Patent Application
20140143419
The present invention relates to networks, the control of these and controllers for these. The invention has particular application in respect to networks such as power substation networks and more particularly those centrally automated using the IEC61850 standard. Further in particular, the invention may relate to the detection of the presence and location of faults or potential faults in a power distribution network.
Various industries rely on networks of devices. One challenge for network engineers is ensuring interoperability and coordinated control of devices and network elements. Another challenge is providing robust network protection for events that disrupt services. Standards have evolved for centralised control or automation of network devices and for communication between devices. These generally rely on imposing a limited number of standardised events, data objects and functionality.
There is a continual need for increasingly sophisticated software applications for controlling networks. Applications involving multiple software agents show promise. One reason for this is that they are well suited to applying intelligence that uses data gathered from different networks elements. However, the implementation of these multiple agent applications can be problematic in industries that rely on the interoperability and robust protection provided by standards for centralised control or automation. The limited events, data types and functionality of standards used in these industries do not facilitate sophisticated distributed applications. Conversely, departure from these standards is not feasible in industries which might provide essential services or—with power distribution networks—deal with potentially lethal voltages and currents.
A variety of different types of device networks designed and implemented using standards for centralised control and/or automation are presently restricted by these circumstances.
For example, one type of network which would benefit from applications involving multiple agents but which is constrained by the need for interoperability and robust operation is electrical power distribution networks, or electricity substation networks. The typical electricity customer might be supplied via a service wire from a three-phase, Low Voltage distribution feeder with a nominal voltage of 240 volts (phase-to-neutral)/415 volts (phase-to-phase). Each LV feeder is supplied by an 11 kV/415V distribution substation, typically a pole transformer or ground transformer. Each distribution substation is supplied via a Medium Voltage MV distribution feeder, with a nominal voltage of 11 kV, phase-to-phase, from a zone substation. Each zone substation is supplied via a 33 kV or 110 kV sub-transmission network from a bulk supply substation. Each bulk supply substation constitutes an interface to the transmission system. A distribution substation might manage 300 zone substations. For each zone substation there may typically be 6-12 11 kV feeders, 80-150 distribution substations and 5000-10 000 customers.
After supplying customers with electricity, the foremost mission critical function of the electricity substation network is protection, this is the detection and clearance of faults and overloads. A fault is defined as an uncontrolled flow of electrical energy due to insulation failure. The simplest form of protection is fuse protection, generally used only at extremities of the network. Elsewhere, faults are detected by protective relays and cleared by circuit breakers. A protective relay processes voltage and current measurements in order to determine the existence, and also in some cases the location, of a fault. A circuit breaker is a type of switch capable of interrupting fault current. Other switch types with less onerous capabilities include load break switches, capable of interrupting load current but not fault current, and disconnectors, only capable of off-load switching for the purpose of isolating equipment for maintenance access.
Faults on 11 kV overhead feeders can be temporary in nature, such as caused by tree branches or animals. Accordingly feeder circuit breakers are often configured with automatic reclosing, a function which re-closes the circuit breaker one or more times after fault clearance in an attempt to restore supply. If the fault is permanent, a lockout occurs and the feeder cannot be put back into service until repaired.
To speed the process of restoring customers blacked out by a fault, an 11 kV feeder may be divided into sections by sectionalising switches, and connected to adjacent feeders via tie switches. Once a fault has been located, sectionalizing switches are opened to isolate the faulted section, and tie switches are closed to restore supply to the unfaulted sections. Computer-based remote control of power system equipment simplifies such processes as restoring power to customers blacked out by a fault. For example, control of sectionalising switches can be done by remote manual control using a Supervisory Control And Data Acquisition (SCADA) system. SCADA is a commonly a feature of zone substations. With improvements in technology, SCADA has become cost effective for distribution system equipment as well. Recently, automated Fault Location, Isolation and Supply Restoration (FLISR) products have begun to appear on the market. These products use the SCADA system as eyes and arms to gather information about faults and execute the necessary control actions, such as the opening and closing of switches.
The IEC 61850 standard introduces various elements of a power system-related automation architecture called Substation Automation System (SAS). According to the IEC 61850, a SAS can be represented in a 3-layered form which facilitates centralized monitoring and automation or control of the network.
The IEC61850 standard also provides a data model involving logical nodes, which are capsules of data, such as Pos, and functionality, such as position indication of a circuit breaker. The functionality of the substation network can be modeled as a collection logical nodes.
A limitation of the IEC61850 standard is that it does not cover the representation of control and automation logic. This limitation of the
The applicant has observed that the IEC 61499 standard can be used to define applications for a wide range of control and automation logic. The IEC 61499 standard describes a general purpose Function Block (FB) architecture for industrial measurement and control systems. A FB is a software unit that encapsulates some behavior. IEC 61499 defines three classes of FBs: basic FBs, composite FBs, and service interface FBs. Each FB has a set of input and output variables. Input variables are read by an internal algorithm when it is executed, while the results from the algorithm are written to the outputs.
In IEC 61499 basic FBs have a state machine which defines the response of the block to input events. The state machine is called an Execution Control Chart (ECC). The response can consist of the execution of algorithms, computing output variables and internal variables as functions of input variables and internal variables, and the generation of one or several output events.
A composite FB encapsulates a network of FBs, both basic and composite, connected to the external data and event sources. The possibility to include composite FBs within other composite FBs enables a hierarchical system description. This is useful for defining multilayered architectures. FB-based architecture also enables modeling and simulation to be tightly integrated with the design process. Before deployment, the controller can be validated by either simulation or formal verification. In the IEC 61499 architecture, the function performed by the system is specified as an application, which may reside in a single device or be distributed among several devices. The application consists of a network of FBs connected by data connections and event connections. The control system is specified as a collection of devices interconnected and communicating with each other by means of one or more communication networks.
The use of FBs makes the control device openly programmable and easily reconfigurable. IEC 61499-compliant devices can easily interface with each other, thus providing for seamless distribution of different tasks across different devices. The user may create their own program using standard FB types. Thus, the IEC61499 architecture enables encapsulation, portability, interoperability, and configurability. Portability means that software tools and hardware devices can accept and correctly interpret software components and system configurations produced by other software tools. With interoperability, hardware devices can operate together to perform the cooperative functions specified by one or more distributed applications. With configurability, devices and their software components can be configured (selected, assigned locations, interconnected, and parameterized) by multiple software tools.
A limitation of the IEC 61499 is that it does not ensure interoperability and robust control of networks. For example, the IEC61499 does not provide an architecture for encapsulating network functions and data or standardized communications between such capsules.
According to one aspect of the invention there is provided a network including a set of network devices and a set of processors operable to control and/or monitor the operation of the set of devices by executing code defining a data-model for the network, the data-model comprising a set of logical-nodes encapsulating network functions and/or network devices, wherein the data-model is structured in a hierarchy for centralised control and/or monitoring, wherein for each logical-node the code defines:
According to a further aspect of the invention there is provided a network of devices including a set of processors operable to execute control code to control the devices, the code comprising a set of node-modules each encapsulating a node of a data-model defined for the network, each node-module comprising:
According to another aspect of the invention there is provided a carrier medium carrying code defining a code module which encapsulates a node-module of a data-model defined for a network, the code module comprises:
According to yet a further aspect of the invention there is provided a processor with data memory and operating memory, said data memory storing a code module which encapsulates a node-module of a data-model defined for a network, the code module comprises:
According to another aspect of the invention there is provided an integrated development environment arranged to assemble a code module which encapsulates a node-module of a data-model defined for a network, where the code module comprises:
According to yet a further aspect of the invention there is provided a network including a set of network devices and a set of processors operable to control and/or monitor the operation of the set of devices by executing code defining a data-model for the network, the data-model comprising a set of logical-nodes encapsulating network functions and/or network devices, the data-model being composed of logical-nodes of defined types conforming to a design standard, the design standard defining allowed interconnections of logical-nodes for centralised monitoring and/or control of the set of devices, wherein the data-model is structured in a hierarchy for centralised control and/or monitoring, wherein for each logical-node the code defines:
According to yet another aspect of the invention there is provided a network substantially as described above wherein the design standard defines a multi-layer data-model with interconnected layers for physical functions, network protection for physical functions, and central automation and human interfacing, whereby a central controller and human interface are adapted to assert control over the network, and said at least one intelligence module implements an agent of a multi-agent distributed intelligence application to participate in intelligence-operations to influence control of the network.
Preferably in this aspect of the invention each logical-node the code defines an interpreter-module having one or more connections for the communication of service-intelligence data and for service-events, each interpreter-module being operable to parse service-intelligence data to service-events.
Reference is made within this specification to the invention incorporating, implementing, providing or otherwise exhibiting features, functions or characteristics defined by a standard or a number of standards. Those skilled in the art will appreciate that these functions or components of the invention should be understood to be provided in compliance with the requirements of such a standard or standards, or potentially are implemented as outlined, described or dictated by a standard or standards.
Preferably the present invention may use design standards to dictate the formulation or construction of a data model of a network and/or the components which make up such a data model of a network. A design standard should be understood by the skilled reader as providing a fixed description, specification or rule set for the design and/or operation of a network and its components.
In some embodiments a standard associated with or for a form of network defines a design architecture, such as, for example a hierarchy of devices and nodes arranged to provide centralised control. For example a design standard provided by IEC61850 details the provision of a Substation Automation System (SAS) represented in a 3-layered form which facilitates centralized monitoring and automation or control of the substation network.
In some embodiments a design standard may define a set of event types and corresponding data types and services to cause given logical nodes perform given network functions. Service-events, data objects, services and functions may be associated according to a given type of logical node.
In a preferred embodiment the design standard employed with the invention may define allowed interconnections of logical-nodes to centralise monitoring and/or control of the set of devices present within the network. In such embodiments the design standard may also dictate that service-modules have a dedicated connection for each type of service-event to be received by the service model, in addition to dictating the types of service-events which a service-module is allowed to receive. This form of design standard restricts the specifics of the design which can be used to implement each logical-node, thereby making monitoring and control of the network a more predictable and easier task.
In a further preferred embodiment a logical-nodes intelligence-module or modules may also be operable to generate service-intelligence data defining the service-events which are capable of reception by the service-module or modules of the type or types defined for the logical-node by the design standard used. In such embodiments this arrangement of intelligence-modules provides the ability for distributed intelligence-operations executed across multiple intelligence-modules to influence control of the network. An intelligence-module resident with in each logical-node is provided with the capacity to supply service-events to a service-module within the same logical-node, where intelligence-operations will be used to determine if and when such service-events should be supplied.
In a preferred embodiment the design standard used by the invention may define a multi-layered data-model. In such an embodiment this data-model may define interconnected layers for physical functions, network protection for physical functions, and central automation and human interfacing. Such a multi-layered data-model may allow a central controller and human interface to assert control over the network being modelled.
In a further preferred embodiment such a multi-layered data model may also incorporate logical-nodes which define an intelligence-module implementing an agent of a multi-agent distributed intelligence application. Such a multi-agent distributed intelligence application can allow distributed intelligence-operations to be completed to influence control of the network.
In addition to a design or design standards the present invention may also use one or more intelligence standards in the formulation of a data-model. For example such intelligence standards may be used to extend the functionality provided by a design standard or potentially increase the operational flexibility of the network involved. For example in some embodiments intelligence standards such as IEC61499 or IEC61131 may be used in the formulation of a data model.
Reference is also made within this specification to the invention providing a network incorporating network devices which may in some instances perform or execute network services. Again those skilled in the art will appreciate that these forms of networks, the network devices provided within them and the network services performed will be dictated by the particular application in which the invention is used. References to networks, network devices and/or network services should in no way be construed as limiting the invention to use in data transmission or information technology networks in isolation.
A data-model utilised in conjunction with the invention comprises a set of logical-nodes encapsulating network functions and/or network devices. Those skilled in the art will appreciate that the network devices represented in the data model may be the actual devices present in the network being modelled. Furthermore, the network functions encapsulated by the logical notes of the data model may representative of any operation, facility and/or service completed by or in association with the network devices and/or the network modelled.
References throughout this specification to modules implemented or provided in conjunction with the invention should be interpreted to encompass any form of module discussed in respect of the invention—such as, for example, service-modules, intelligence-modules and/or interpreter-modules.
A logical node includes at least one intelligence-module, control module, or controller which provides intelligence for the behaviour of the logical node represented by the module. The intelligence-module has code to implement algorithms which may or may not conform to the standard used by the service interface module.
Preferably the devices in the network are connected so as to provide centralised monitoring and/or control of the network. In a further preferred embodiment the devices are connected in a hierarchy.
Preferably the data-model includes groups of logic-nodes structured to form a logical device as defined by a standard.
Preferably each processor is associated with a device and operable to control the associated device dependent on data stored by a service-module.
Preferably a device may be a logical device as defined by a standard or a physical device.
Preferably the data-model is defined by a standard. In a further preferred embodiment the standard is IEC61850.
Preferably modules are provided by IEC61499 or IEC61131 standard compliant function blocks.
Preferably the code defining each logical-node or module includes an event driven algorithm and a scheduler.
Preferably one or more modules is a composite module formed from other modules.
Preferably the network is a power distribution network. In a further preferred embodiment the network is a power distribution substation
Preferably intelligence-operations include protection and/or monitoring processes for the network.
Preferably an intelligence-module implements an agent of a multi-agent distributed intelligence application to participate in intelligence-operations.
Preferably intelligence-operations include bartering algorithms involving bartering between agents associated with two or more logical nodes or two or more logical devices
An intelligence-module is arranged to exchange intelligence-events and intelligence data objects with other intelligence-modules. These intelligence-events and intelligence data objects allow for the control of the network when utilised by intelligence-operations which are executed in a distributed architecture across number of intelligence-modules. Intelligence algorithms run in conjunction with each intelligence-module allow an intelligence-module to participate in such distributed intelligence-operations.
Intelligence-modules generate service-intelligence-data which can be provided to service interface modules to define and provide standards compliant service-events and service-data objects. These standards compliant service-events and-service-data objects can differ from the intelligence-events and intelligence data objects communicated between intelligence-modules which need not be standards compliant. The skilled reader will appreciate that these intelligence-events and intelligence data objects may utilise any desired arrangement of a data structure, function or data organisation scheme which allows intelligence-modules to generate service-intelligence-data which can effectively control the network involved.
In a preferred embodiment a user may define arbitrary code for the intelligence-module, for the behaviour of logical nodes, independently of any code defined for the service interface module, for interoperable communication between logical nodes. In such instance the service-interface module can interface with other logical nodes using service-events and service-data objects that conform to the standard used by the logical node and performs operations which conform to services defined by the standard. Therefore, the service interface module can provide for standardised communication and assured interoperability of logical nodes according to the standard, irrespective of any code or operations implemented by the intelligence-module. The intelligence-modules of this embodiment may be recognised as user-defined because a user can define code independently of the standard defining communication and services.
One additional aspect of the present invention provides a network controlled using a data model which represents the network logically as a set of nodes each representing a network function or network device and controlled by executing a set of node-modules which are each operable to store data for a corresponding node and which are each able to communicate with other node-modules for the control of the network, wherein each node-module includes:
The data model may be adapted to facilitate the determination of faults and/or the location of faults in the network. The data model may be adapted to facilitate centralised automation for protection in response to faults in the network. The data model may be adapted for centralised monitoring of data describing faults on the network.
The behaviour may be for one or more network devices.
The node-modules may include blocks which are able to participate in the exchange of events and able to perform event-driven operations. The standardised events and data-types may be standardised according to the IEC61850 standard. The blocks may be function-blocks as defined by one of the IEC61499 and IEC61131 standards. The node-modules may comprise connections between the data-module and the behaviour-module. The controller-module may include an interpreter-module able to interpret data or events from the behaviour-module into standardised events.
A further aspect of the invention provides a network including a set of logical nodes as defined by the IEC61850 standard, the network executing one or more function blocks of software, each function block including a network of event-driven capsules each operable to exchange events with other event-driven capsules. The event-driven capsules may conform to a reference architecture for distributed software systems.
One aspect of the present invention provides a network of physical devices each controlled by one or more logical node software-modules, the software-modules grouped according to a standardised data model as logical-devices, wherein a logical device is logical analog to a physical device, each logical node communicating using standardised events and standardised data-types, wherein a logical node software-module includes code which when executed:
A logical node-software-module may be able to perform one or more operations so as to implement standardised services.
The network of physical devices may be provided as components of a power distribution network, each physical devices being controlled by a group of logical node software-modules grouped according to a standardised network model as logical devices. For example in a preferred embodiment where the invention employs IEC 61850 as the design standard to be used, a logical device may be provided equivalent to the description of IEC61850. Such logical devices may be used to represent the characteristics or functions of a physical device or a subset of characteristics or functions of a physical device.
The software module may include a connection between the controller and the database for service requests.
One aspect of the present invention provides a network of devices controlled using data stored by a group of logical nodes such as defined by the IEC61850 standard, the network including a logical node-code-module associated with each logical node and including one or more processors operable to execute the logical node code-modules to control the devices, wherein each logical node code-module includes:
The logical node code-module may include one or more service-connections between the service-module and the intelligence-module, the one or more service-connections being operable to communicate data identifying a service as defined by the IEC61859 standard to allow the intelligence-module to control the logical node by identifying services.
The logical node code may be implemented using event-driven code-blocks each including an event-driven algorithm and each including one or more connections for events. The one or more event-driven code-blocks may include one or more schedulers operable to schedule the algorithm as part of a distributed operation. The one or more event-driven code-blocks may be function-blocks such as defined by one of the IEC61499 and IEC61131 standards.
The service-module may be operable to store data defining the logical node with which the code-module is associated. The data stored may define the state of a logical node forming part of a logical device which is a logical analog to a network device. Therefore, a group of logical nodes may be able to store data representing the state of a device. The service-module may include code defining one or more algorithms operable to respond to the set of events to perform operations such as defined for services of the IEC61850 standard. The operations may include any one or more of: receiving data, storing data, updating stored data, sending stored data, and generating events for given logical nodes.
The service-module may include a data-module connected to the service-interpreter-module by a set of service-event connections. The data-module may include data-connections for receiving data objects to store. The intelligence-module may include data-connections to communicate data-objects to the data-module.
The service-module may include a service-interpreter-module operable to parse service-request-strings received in a string-data-type into service-events. The service-interpreter-module and data-module may have corresponding sets of event-connections for communication events. The sets of event-connections may be defined by a standard for the network. The corresponding sets of event connections may be defined by the service requests of the IEC61850 standard.
The data-module may include an event connection for each service defined for the network. Services defined for the network may be defined by the IEC61850 standard.
The data-module may include code defining algorithms to send service-events in response to service-events received at the event connections. The data-module may comprise code defining algorithms to perform one or more of updating, sending and receiving data in response to events received at the event connections. The data-module may include a database.
The network may comprise logical nodes associated with node-locations representing locations associated with logical nodes and the network may include processors at the node-locations to execute the logical node code associated with the respective node-location.
The intelligence-module may implement one or more function-blocks. The service-module may include one or more function-blocks. The logical node code may be implemented entirely using function-blocks. A function-block may be event-driven. A function-block may be operable to exchange events. A function-block may comply with a distributed system architecture. One or more of the event-driven, event exchange or distributed architecture functionality may be as defined in the IEC61499 or IEC61131 standards.
One aspect of the present invention provides a method of controlling a network of devices communicating using service-request-events and data-objects defined by the IEC61850 standard, the method including:
One aspect of the present invention provides a set of processors distributed across a power substation network to control logical nodes of the substation network, wherein a logical node is defined according to the IEC61850 standard, and wherein each processor executes a logical node-code-module which includes:
The logical node code-module may include a connection between the intelligence-module and the service-module to allow the intelligence-module to identify service-requests defined by the IEC61850 standard.
Each processor may implement a service-interpreter-module operable to parse data from the intelligence-module into event types defined by the IEC61850 standard, wherein the data identifies service-requests.
The processors may execute code which is defined by one or more of the IEC61499 or IEC61131 standards.
One aspect of the present invention provides a device controller in a network using communications between a set of logical nodes as defined by a data model of the IEC61850 standard, the device controller including:
The behaviour controller may be operable to generate service-request data identifying IEC61850 compliant service-requests.
The service-interface may include a connection for receiving service-request-string data of a string data-type to respond to service-events determined by the intelligence-module.
The service-interface-module may include a data-module operable to perform processes representing services defined by the IEC61850 standard in response to service-request events.
The service-interface may include a service-interpreter-module including one or more connections operable to receive service-request-string in a string data-type data from the intelligence-module, and including event connections operable to provide service-request-events for the data-module, the service-interpreter-module operable to parse service-request-string data into service-request-events.
The service-interface-module may include a data-module operable to perform processes representing services defined by the IEC61850 standard dependent on service-request-events and data-objects. The data-module may be operable to store data using hierarchies of data-types defined for the network. The data-module may be operable to store data using data-types defined by the IEC61850 standard. The data-module may include event connections for events defined by service-requests and data-connections for data objects.
One aspect of the present invention provides a network of devices modelled as logical nodes which logically perform one or more network functions, the network including a logical node code-module associated with each logical node and including one or more processors operable to execute the logical node code-modules, wherein each logical node code-module includes:
One aspect of the present invention provides a processor operable to control devices in a network using communications between logical nodes operable to perform a one or more defined network functions, the processor executing logical node code including:
The network may include a heterogeneous set of devices.
The devices may be devices in an electricity substation network.
One aspect of the present invention provides an electricity substation network including devices operable to collectively perform network functions and including controllers operable to control the behaviour of groups of devices, the devices grouped logically such that a group is able to perform one or more network functions by communicating using a set of event types standardised for the network and a set of data types standardised for the network, the code including:
In one further aspect the invention provides an automated electrical power distribution network including a set of devices operable to distribute power from a bulk supply substation to multiple end-user sites, to perform protection operations for the network and to perform monitoring of the network, the devices connected in a hierarchy so as to provide centralised monitoring and/or control of the devices, the network comprising a set of processors operable to control the devices, the processors also operable to execute code defining a set of logical nodes providing an information model of the network and performing service-algorithms to update stored control-data used the by processors to control the devices, wherein code defining each logical node comprises a set of function blocks, and wherein the set of function blocks comprises:
Each function block may comprise one or more algorithms and one or more state machines operable to control the execution of the one or more algorithms.
The data block may update data using data-types defined by the standard.
The data block may be operable to update data and perform corresponding services so as to encapsulate the data and service or services.
In a further aspect of the invention an integrated development environment or IDE is provided. An IDE can facilitate the formulation and assembly of the code modules which implement a data model defined for a network.
In embodiments where an IDE is provided the IDE may also incorporate or have access to a library of code elements. These code elements may be reviewed by a user who can make selections from the library during the design of a particular code module to be provided for the data model of a specific network.
Aspects of the present invention provide a computer readable carrier or medium bearing code which if executed causes the computer, or processor, to perform processes or methods or to configure the computer operate according to any of the paragraphs above.
Aspects of the present invention provide a computer having a processor, program memory and data memory, the data memory storing code which if executed causes the or processor to perform processes or methods or to configure the computer operate according to any of the paragraphs above.
Aspects of the present invention provide control of a network using an object-oriented code modules each encapsulating a network function or device wherein the code module is implemented using event-driven code-blocks which include event-driven algorithms and connections to exchange events with other code-blocks. The event-driven code-blocks may be functional-blocks as defined by the IEC61499 or IEC61131 standards.
Aspects of the present invention provide control of a network using an object-oriented code-module encapsulating a network function or device wherein the code module includes one or more code-blocks which participate in intelligence applications involving other object-oriented code modules.
Aspects of the invention may provide control of a network of network devices the network being operable to perform network functions, the control using code modules which encapsulate network functions and/or network devices and associated data, wherein the code modules include a database encapsulating nodes of an information model as defined by a standard and implementing communication with other nodes according to a standard for centralised automation of the network, and wherein the code modules include one or more function blocks implementing the network functions.
Aspects of the present invention provide control of a network using an object-oriented code-module encapsulating a network function or device wherein the code module includes a service-module operable to perform operations to implement a defined network service in response and operable to communicate using standardised data types defined for the network function and includes an intelligence-module for the implementation of intelligence for behavior of the data module. The intelligence-module may be operable to communicate using data types additional to the standardised data types. The service-module may be responsive to defined service-request-events.
Aspects of the present invention provide control of a network using object oriented code-modules each encapsulating a function or device of a network wherein the code module includes a data module operable to perform operations to implement the network function and operable to communicate using data types defined for the network function and an includes an intelligence-module for the implementation of intelligence for behavior of the data module, and a service interpreter operable to interpret signals from the intelligence-module for the data module.
Additional and further aspects of the present invention will be apparent to the reader from the following description of embodiments, given in by way of example only, with reference to the accompanying drawings in which:
a illustrates an example user defined type implementation of a Common Data Class (CDC) according to a preferred embodiment of the present invention;
b illustrates function blocks implementing a Common Data Class according to a preferred embodiment of the present invention;
c illustrates function blocks implementing a database module according to a preferred embodiment of the present invention;
a also illustrates operation of a substation network according to a preferred embodiment of the present invention;
Further aspects of the invention will become apparent from the following description of the invention which is given by way of example only of particular embodiments.
Data modelling of a network of devices according to IEC61850 is depicted in
The devices of the physical layer 3, such as circuit breakers, are connected via communication channels to protective relays (not shown) and bay controllers 4a and 4b of a second layer 4. The devices 4a and 4b in the second layer implement network functions such as protection, monitoring, control and automation tasks in a particular responsibility area, or area of operation. This area might be known to the reader as a bay. The top level 5 of the hierarchy has a substation automation unit 5a, which i) integrates and controls several bays within a substation ii) implements a human-machine interface 5b and iii) communicates with a control centre (not shown). The reader will recognise that the top level implements centralised control and automation of the network.
A set of Logical Nodes (LN) 8 each encapsulate data, such as Pos and network functionality, such as providing in response to a request data describing the circuit breaker position. The IEC61850 standard describes the interdependencies between the logical nodes 8 within devices and across the network. The functionality of a substation network can be modelled as a collection of logical nodes 8 or as a collection of logical devices 9 populated by logical nodes 8. These nodes affect a set of network functions.
The logical node module 10 represents a data and function capsule which stores data representing the state of the logical node and performs functions representing the function encapsulated with the data. The logical node module 10 also communicates and responds to other logical node modules using a set of standardised data objects and events. The standardised data objects represent real-world communication signals within or between parts of a physical device. The logical node module 10 performs functions, dependent on receiving events and data in the form of objects. As known to the reader the functions are manifest as updating data or generating data objects to be communicated to another logical node code module 10. In the case of this embodiment the data objects and services are defined by the IEC61850 standard. Events in the form of requests for services or service requests and may be accompanied by corresponding data objects. For example a logical node 8 representing a circuit breaker position description will generate a Pos data-object in response to receiving a corresponding service-request. The IEC standard defines a list of services which intelligence within a logical node can use to implement a given function. An example of such a function is the overcurrent function, encapsulated by an PIOC LN, which can use an operate service to indicate to a protection trip conditioning function encapsulated by PTRC LN to indicate that a fault has been detected. Therefore, services are used for communications between logical nodes 8 which encapsulate functions.
The logical node module 10 has a service-module 11, database-service-interface or service-interface, which interfaces with other logical nodes 8 communicating using service-event and data objects defined by the standard. The service-interface-module 11 encapsulates data stored to define the logical node 8 of the data model used for the network (not shown) and functionality for the logical node. In this embodiment the data is stored according to data types defined by the IEC61850 standard and the functionality is defined by services of the IEC61850 standard. The service-module 11 receives or exchanges events and data objects defined by the standard and stores data in the standardised data types. These event and data objects may be described as service-events and service-data objects respectively. The service-interface module 11 has code defining algorithms to perform operations representing the services. In this embodiment the algorithms are defined according to the IEC61850 standard.
The logical node 8 also has an intelligence-module 12, control module, or controller which provides intelligence for the behaviour of the logical node represented by the module 10. The intelligence-module 12 of this embodiment has code to implement algorithms which may or may not conform to the standard used by the service interface module 11.
An integrated development environment (IDE) is provided according to this embodiment which allows a user to program arbitrary intelligence functionality which is compiled into an intelligence module 12, which in turn is compiled into a logical node module 8 along with a service module 11. This arrangement and the IDE provided by the invention means that the services and functions of the logical node 8 are ensured to be interoperable, robust and centralised, while at the same time the logical node can be influenced by intelligence functionality.
A user may define arbitrary code for the intelligence-module 12, for the behaviour of logical nodes 8, independently of any code defined for the service interface module 11, for interoperable communication between logical nodes. The service-interface module 11 interfaces with other logical nodes 8 using events and data objects that conform to the standard used by the logical node and performs operations which conform to services defined by the standard. Therefore, the service interface module 11 provides for standardised communication and assured interoperability of logical nodes 8 according to the standard, irrespective of any code or operations implemented by the intelligence-module 12. The intelligence-modules of this embodiment may be recognised as user-defined because a user can define code independently of the standard defining communication and services.
In this embodiment the intelligence-module 12 participates in distributed intelligence for the behaviour or control of logical nodes 8. The reader will recognise the intelligence-module 12 as forming part of a distributed intelligence application with the intelligence-modules of other logical nodes 8. The operations completed by this distributed intelligence application can be described as intelligence-operations. The distributed intelligence application of this embodiment is a multiple agent application distributed over a network (not shown) and is able to gather data from logical nodes 8 at different parts of the network and perform intelligence-operations to coordinate the network. The distributed application also defines service events for the service module 11 so some of the control of the network is dependent on intelligence functionality provided by intelligence-modules 12.
The service interface module 11 of this embodiment has a database 13, or data-module, which provides the standard specific encapsulation of data and services to represent the logical nodes 8 and a service interpreter 14, service interpreter or interpreter-module, to interpret communications, or signals, from the intelligence-module 12. In this embodiment the service interpreter module interfaces with intelligence-module 12 and other logical nodes (not shown), via the intelligence-modules of those other logical nodes 8. In this embodiment also the service-interpreter parses data in a string data type into events which conform to the standard. This allows the intelligence-module 12 to interact with a database which conforms to the standard and thereby ensures interoperability of logical nodes 8 and physical devices (not shown) controlled using the logical nodes 8. In some examples with given embodiments, communication between intelligence and service-interpreter modules within a logical node 8 or 10, need not necessarily comply with the standard, because the communication is within a logical node and the standard is conformed to between logical nodes 8.
The communication between the intelligence-module 12, the service-interpreter-module 14 and the database module 13 is defined by algorithms defined in code for the intelligence block.
The connection between service interpreter 14 and database 13 blocks have output event connections of the service interpreter block 14 corresponding one-to-one to the input event connections of the data base block 13. The interpreter block 14 parses requested services and outputs corresponding service-event and the database performs requested services upon receiving the service corresponding event. Data inputs and outputs of the database block 13 interfaces to the external logical nodes (not shown in
The data connections between the service-interpreter-module 14 and the database-module 13 are unified and the same for all types logical node 8. Here a type is defined by the device or function modelled by the logical node 8 and may be implemented as a type that is supported by a given Intelligent Electronic Device (IED) of a network.
The Intelligence block 12 performs user defined-logic and requests services from its local database block 13, in the same logical node 8, and from other logical nodes 8. To interface its local database block 13 and allow other logical nodes 8 to request service from it, events and data from the service interface block 14 and database block 13 have to be available for the internal intelligence block 12 and for the external interface of a logical node. Thus the data and events of the service and database module are shared between its local intelligence block and external LNs. To enable sharing of the common resources, merge block 18 is introduced in this implementation to multiplex service requests from the local intelligence block 12 and external service requests into single service interface block 14 and single and database block 13.
In this embodiment the service-interpreter module 14 may be implemented with either a single functional block or multiple functional blocks. It will be apparent to the reader which is preferable in a given instance.
The database 13 also operates to perform algorithms or operations corresponding to services, defined by the standard for the logical node 8. The database 13 performs these in response to service request-events, also known as service-requests. The response to given service requests is defined by the standard. Input service requests are associated with corresponding data according to functional constraints defined by the standard for the data-objects. In this embodiment the database-module 13 can be implemented using one or more function blocks.
The present embodiment uses the service-interpreter-module 14 to request standardised data from the database-module 13 needed for assigned tasks.
As shown in
The intelligence-module 12 of this embodiment is implemented using event-driven code capsules which are able to exchange events with each other. Typically, the capsules each have code defining an algorithm and defining a scheduler. This particular embodiment is implemented using functional blocks defined by the IEC61499 standard. These intelligence-modules may comprise intelligence from other intelligence-modules 12 or functional blocks making up these which are performing sub functions. For instance, in PIOC LN intelligence block (
Communication flows within a logical node-module 10 are illustrated in
The intelligence-module 12 also receives and generates intelligence dependent communications 42 and 43 dependent on intelligence algorithms.
The data structures used by the logical nodes 8 of embodiments of the present invention will now be illustrated with reference to
In the present embodiment CDC are modelled as User Defined Types (UDT s) as defined in the IEC61499 standard. UDT s allow wrapping of simple types as well as complex types into a single higher-hierarchy complex type.
In the example illustrated in
An example of an implementation of a logical node 10 of an embodiment of the invention using nxtControl and isaGraf tools is illustrated with reference to
On the figure an example of UDT implementation of CDC is shown. UDT 72, implementing a Single Point Status SPS CDC, is the highest level of data hierarchy. SPS type contains data attributes 73 of simple types stVal of type BOOL, subEna of type BOOL, subVal of type BOOL74. Also it contains data attributes 52 of complex types—q of type Quality 52. This is the next stage of hierarchy. Data attribute q consists of simple 75 (String) and complex (detailQual) data 76. detailQual 76 representing details of quality of this data attribute is a complex data type—packed list. As known to the reader, a packed list is the lowest level of data hierarchy and consists of simple types only.
a, shows an example implementation of Double Point Control DPC CDC in nxtControl is shown. As the reader will be aware, nxtControl does not currently support UDTs. Details of the CDC attributes are given in IEC 61850-7-3 page 44 table 41. In this embodiment UDTs are modelled as basic function blocks 192 with read and write services and data attributes 194-199 flattened out, because the convenience of using a UDT is not available.
As shown in
An example of communication between logical nodes 8 of an embodiment of the present invention is illustrated by
Collaboration between logical node-modules 10 starts when a fault occurs on one of the feeders 150, feeder 1, at the position of circuit-breaker 1, 151. Logical node 8 implementing the protection functions trip CB 1151, reclose it and, if the fault is permanent, and auto-closing function will set to lock-out. The arrows 152 depict upstream (up the page) and downstream (down the page) communication flows respectively. Once the fault has been located by Protection Instantaneous Over Current PIOC (LN for overcurrent protection, relay), and Control SWItch CSWIs (switch controller LN) are informed of the fault location on the section 150, section1, of CB1. The CSWIs that do not have a fault on their respective sections send help signals to tie switches to request searches for alternative supplies. For example the ROS 1 sends a help 200 as shown in
As the reader will be aware, a full list of services described in
An exemplary service-interpreter-module 14 implemented as a function block 500a and a corresponding state-machine 500b is illustrated in
An exemplary database-module 13 and a corresponding state-machine are illustrated in
An exemplary intelligence-module 12, in this example a function Block 517a, and a corresponding state-machine 517b is illustrated in
A more detailed example of a Protection for Instantaneous Overcurrent (PIOC) intelligence block 12 is illustrated in
The algorithm for location of the fault starts once intelligence block 12 gets LOCKOUT input event. Once the intelligence block 12 starts locating the fault: it sends the state request to stateRequest for its own state identified in the 323 FaultInform block. Once the Lockout block 321 block gets stateReply it emits state to notify the Adds block 323 about the PIOC state after lockout. In the case where the PIOC state is normal then PIOC 312 moves to notMyFault state and waits for the FaultLocatedPIOC event, then it moves into faultLocated state and propagates FaultLocated event. If the PIOC state is fault PIOC moves to MyFault state and issues FaultLocatedPIOC and transfers to faultLocated state. In this state PIOC 12 (Lockout FB 12) informs corresponding CSWI about the fault location. Either PredefaultState or CSWIReady events will make PIOC 12 transfer to the normal state. CSWIReady implies that corresponding CSWI is ready to get an alternative supply, and PIOC has to come back to normal state to react on fault current as the supply is restored.
An example of a Function Block implementation of a Logical Node 8 is shown in
Further and additional embodiments of aspects of the invention will now be described. In some embodiments the intelligence-module is formed of sub-modules which each perform sub-functions of the functions performed by the intelligence block. In some embodiments modules described herein are implemented as source code modules by various means known to the reader. In one example, a module may be defined by a namespace. In other embodiments the modules described herein may be implemented as object code for a computer, or processor of an Intelligent Electronic Device. In other embodiments modules may be implemented as firmware or as hardware description language, such as VHDL, or as hardware such as known to the reader and including Field Programmable Gate Arrays (FPGA s) or Application Specific Integrated Circuits (ASIC s). The modules, or blocks, described herein with reference to given embodiments contain code which performs operations described when executed. Depending on the implementation of the modules various embodiments of the invention implement connections for data objects or events include argument variables, software methods such as set or get methods, interface classes, XML or other data files, physical connections or other known connections for data objects, or events.
The code of various embodiments may be stored on computer or processor readable media including EEPROM, Flash Memory, other volatile or non-volatile memory, magnetic or optical storage media, or other known storage media. For some embodiments the code may be carried using carrier media including electronic, or optical carrier signals, or communication protocols including TCP/IP, FTP, EtherNet, or other known carrier media.
In reference to some embodiments, the term module describes a functional unit which may represent source or object code or even hardware. In some embodiments modules are function blocks. In some embodiments the function blocks are IEC61499 compliant function blocks or blocks which have one or more characteristics of the IEC61499. In other examples the modules are implemented as source code functions or classes which are defined by the user to provide connections, outputs and functionality described with reference to modules. In some embodiments the modules described in reference to the embodiments above are combined or divided into other modules as known to the reader to be appropriate for given applications or implementations. In some embodiments of the present invention software modules are replaced or interchanged with hardware modules or firmware modules. In some embodiments the functional units represented in the description as modules are provided using dedicated hardware, such as FPGA s. In some embodiments the software modules for a number of logical nodes 8 may be executed on one processor.
In some embodiments all logical nodes 8 forming a logical device may be executed on single processor co-located or otherwise associated with a physical device. Other embodiments may involve execution of an arbitrary number of logical nodes 8 for a network on one processor. For other embodiments one or more logical node-modules may be implemented on a dedicated processor associated with an intelligent electronic device which is provisioned to support given types of logical node as defined by a standard.
Some embodiments provide a compiler or Application Programming Interface (API), or Software Development Kit (SDK) which allows a user to defined code for the intelligence-modules defines logical node-modules but defines the rest of the logical node-module. In some embodiments, code developed or compiled may conform to a standard for distributed applications, such as the IEC61499 standard. In other embodiments code may conform to the IEC61131 standard. Other embodiments may use function blocks of both the IEC61499 and IEC61131 standards. In some embodiments the entire logical node module is implemented using function blocks, but in alternative embodiments only some of the modules within the logical node module, such as the intelligence-module is implemented as function blocks.
Embodiments of the present invention provide a power distribution network using a data model adapted to facilitate centralised monitoring and/or automation to perform protection functions in response to faults on the network, the data model defining logical node software modules and defining services to be performed by the logical nodes, defining events to request services and defining data types associated with the services, the devices having associated processors which implement logical devices being analogs of the physical devices the logical devices comprising sets of logical node modules which each include:
a service-module which performs the services in response to the events and stores data according to the data types; and
one or more intelligence-modules which communicate with the intelligence-modules of other logical node modules and communicate with service-modules and adapted to perform functions to facilitate data collection from points on the network and/or bartering operations to determine a configuration for the network in response to the detection of faults.
In some embodiments the functions comprise part of a multi-agent operation. Some embodiments allow a network that uses a data model that defines a hierarchy for centralised monitoring and protection automation or control for reconfiguration by an operator to implement intelligence that uses data and/or operations from multiple points around a network or which uses multi-agent processes involving agents distributed over the network.
Embodiments of the present invention implement control of physical devices by making available to these devices data defining the logical node and the identifying the state of the logical node using data base modules or service-modules. Various embodiments use any means for making the data available known to the reader.
In embodiments of the present invention the intelligence-module enhances a power distribution system, or transmission or other electricity powers systems, or a network that has centralised monitoring and automation for network and/or reconfiguration and assured interoperability with agent-based control. Some embodiments allow the system or network to be self-aware self-healing, alive and interactive.
In some embodiments the service-interpreter assures interoperability through the use of standardised data structures and/or defined communication mechanisms and the intelligence-module provides user-defined algorithms for flexible and self-configurable agent-based control of logical nodes and equipment associated with them.
The processor of embodiments of the invention is operable to control the behaviour of the group according to event-driven algorithms distributed across the network and the devices can be controlled with assured interoperability as part of a network of devices.
In embodiments of the invention the behaviour of the group can be controlled by code defined by given users of the processor by providing code only for the intelligence-module with assured interoperability of logical devices and/or nodes in the network.
In the preceding description and the following claims the word “comprise” or equivalent variations thereof is used in an inclusive sense to specify the presence of the stated feature or features. This term does not preclude the presence or addition of further features in various embodiments.
It is to be understood that the present invention is not limited to the embodiments described herein and further and additional embodiments within the spirit and scope of the invention will be apparent to the skilled reader from the examples illustrated with reference to the drawings. In particular, the invention may reside in any combination of features described herein, or may reside in alternative embodiments or combinations of these features with known equivalents to given features. Modifications and variations of the example embodiments of the invention discussed above will be apparent to those skilled in the art and may be made without departure of the scope of the invention as defined in the appended claims.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/NZ2012/000126 | 7/19/2012 | WO | 00 | 1/16/2014 |
| Number | Date | Country | |
|---|---|---|---|
| 61509558 | Jul 2011 | US |
