Patent Application
20130018490
The subject matter disclosed herein relates to generator control systems and more particularly to a web-based operator control interface for generator control systems.
Generator control systems typically include a generator coupled to an exciter and static starter to provide excitation current to start-up and operate the generator. Generator control systems can further include a computer and human local operator interface to allow an operator to configure and trouble shoot the generator control system. Typical local operator interfaces implement a custom hardware platform with custom third party software and communicate between the computer and the control system components via an RS232 serial link. This approach can limit installation flexibility and ability to easily make enhancements, and require rework to address component obsolescence issues. In addition, embedded controllers for generator systems can be charged with subservient tasks, increase overhead and can interfere with real-time operational requirements of the generator system.
According to one aspect of the invention, a web-based operator control interface system is described. The system can include an operator interface section including a web browser application, a generator exciter section or a static starter section coupled to the operator interface section, a generator coupled to the generator exciter section and a web server application configured to receive processing requests from the web browser application, and further configured to internally process real-time generator functions.
According to another aspect of the invention, a web-based operator control interface method for a generator system is described. The method can include receiving requests from a web browser application residing on an operator interface section of the generator system, delegating generation of the requests for the web browser application via common gateway interface calls, internally processing requests in an embedded controller, related to real-time generator functions of the generator system via internal common gateway interface functions and delegating non-real time tasks to the operator interface section.
According to yet another aspect of the invention, a computer program product including a non-transitory computer readable medium storing instructions for causing a computer to implement a web-based operator control interface method for a generator system is described. The method can include receiving requests from a web browser application residing on an operator interface section of the generator system, delegating generation of the requests for the web browser application via common gateway interface calls, internally processing requests in an embedded controller, related to real-time generator functions of the generator system via internal common gateway interface functions and delegating non-real time tasks to the operator interface section.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
In exemplary embodiments, the operator interface 105 is an interactive physical interface between an operator and electrical or mechanical equipment such as an embedded controller, which can provide features such as control inputs, configuration, status feedback, and diagnostic information. The operator interface 105 can therefore include a computer 110 and a web browser application 115 residing on the computer 110. In exemplary embodiments, the computer 110 can include a touch screen that can include a graphical user interface (GUI). For illustrative purposes, the computer 110 can therefore be a touch screen computer. As such, when buttons are pressed on the touch screen, signals are generated that send commands to the computer 110. The web browser application 115 can be a software application that interfaces between an operator and a web server using a HyperText Markup Language (HTML) communications protocol.
In exemplary embodiments, the generator exciter system 150 supplies and controls power to a generator field supplied to the generator 175, such that generator output is regulated. The generator exciter system 150 can include a fully static power converter, or a static regulator and a rotating exciter that amplifies the regulator output before applying it to the generator field. In exemplary embodiments, the generator exciter system 150 therefore includes a power converter 155 that can be a solid state device for supplying a large ac or dc load in a regulated manner from one or more unregulated alternating current (AC) or direct current (DC) power sources 160. The power converter 155 can be configured to provide a variable DC voltage output from either an AC or DC power source. The generator exciter system 150 can further include an embedded controller 165 that can be a processor-based control system including various I/O interfaces, for controlling a system such as the power converter, an exciter, or a static starter 180. In exemplary embodiments, the static starter 180 is a system for initially spinning the generator 175 up to a suitable speed from standstill by operating it as a synchronous motor. As such, the embedded controller 165 is operatively coupled to the power converter 155, and the static starter 180. The generator exciter system 150 can further include a web server application 170, which can be a software application configured to provide data in response to communication requests from remote web client applications, such as through the operator interface 105, connected via an interface such as Ethernet via the HTML communications protocol.
In exemplary embodiments, the embedded controller 165 can be a simplex controller or a redundant controller in which one controller is an active controller and one or more additional controllers are available to become active if the active controller fails. The web server application 170 can therefore reside on one or more controllers redundantly. In exemplary embodiments, in the event of a failure of an active controller, the web server application 170 as well as the web browser application 115 on the operator interface section 105 automatically re-establishes communication with a new active controller.
In exemplary embodiments, the generator 175 is a rotating synchronous machine including a rotating field winding for producing a magnetic field and non-rotating stator windings for converting steam, hydro, or combustion energy to electrical energy. It will be appreciated that the generator can be any machine in various exemplary embodiments.
As such, the web server application 170 is a web-based interface between a local operator station or human-machine interface (HMI), (e.g., the operator interface 105) and generator control systems that generally include components such as the generator exciter 150, the generator 175 the static starter 180, and any other static or rotating field exciters. The web server application 170 can be portable and compatible as systems are upgraded. In exemplary embodiments, the embedded controller 165 can include any web server, which is a component of the web server application 170, which runs in the background. It will be appreciated that the embedded controller 165 (including the web application 170) meets real-time operational requirements of the excitation or static starter systems (e.g., the generator exciter 150 and the static starter 180), and this function must not be compromised by subservient tasks such as the web server.
The web server 205, in general, handles a connection to the system 100 via an HTTP request from a browser (e.g., from the browser on the operator interface 105) beginning with a listen( )command 305 on a TCP socket, for example, followed by an accept( ) command 310. The web server 205 then creates a worker thread 325 to handle the connection. The worker thread 325 handles background tasks that do not compromise the critical generator tasks that are performed in addition to the subservient tasks. For example, tasks such as recalculation and background printing are tasks handled by the worker thread 325. In addition, the worker thread 325 creates an external shell 340 that processes CGI commands. The worker thread 325 further creates a process 335 to run the external shell 340. However, the typical process of locating the CGI command file, creating the shell and processing the command can compromise the critical generator tasks can be prohibitively expensive from a memory and CPU context switching perspective. For subservient tasks, the web server 205 implement the find CGI command file, create the shell and process the command pattern.
In exemplary embodiments, for generator critical tasks, the embedded controller 165 implements CGI in the web server 205 to interface with the generator components of the system 100 internally without the need to implement the listen( ) accept( ) create worker thread, find CGI command file, create the shell and process the command pattern. Instead, the web server 205 includes internal functions 320 that do not have to be created externally as with the listen( ) accept( ) create worker thread pattern. Instead, the internal functions 320 create the worker thread 325, CGI file calls 330 and process 335 to create internal CGI shells, that do not make calls to the external shall 340. The embedded controller 165 implements CGI for simplified internal calls. Internal CGI processing does not create separate processes associated with external calls such as disk I/O and context switches (e.g., via GCI Lite). External CGI calls include lengthy disk access reads to find appropriate CGI script or binary. In addition, at least one process consuming considerable memory is created with many context switches. In exemplary embodiments, when the web server 205 creates the worker thread 324 to service a particular connection, code associated with CGI decides whether a CGI call matches an appropriate internal call with a compare statement and proceeds to make the function call rather than creating a shell process to interpret or run CGI code.
In exemplary embodiments, the system 100 implements AJAX (Asynchronous JavaScript and XML) technology, which places the burden of computation on the operator interface section 105, which is the web client (the local operator station or HMI computer platform) rather than on the web server 205 and the embedded controller 165, which address the generator critical tasks. As such, the operator interface section 105, via AJAX, can retrieve data from the embedded controller 165 (and web server 205) asynchronously in the background without interfering with the display and behavior of web server application 170. The operator interface section 105 can retrieve data from the embedded controller 165 via an HttpRequest( ) object 350, which is an AJAX data call. The HttpRequest( ) object 350 retrieves data from the embedded controller 165 in XML format allowing all of the processing to be completed on the operator interface section 105 by traversing the DOM (Document Object Model) tree and interpreting and parsing the results as they become available. In AJAX, DOM is a cross-platform and language-independent convention for representing and interacting with objects in HTML, XHTML and XML documents, and can be accessed with JavaScript to dynamically display, and to allow the user to interact with the information presented. JavaScript and the HttpRequest( ) object 350 provide a method for exchanging data asynchronously between the web browser application 115 and web server 205 to avoid full page reloads. As such, the processing performed on the operator interface section 105 via AJAX does not burden the embedded controller 165 compared to JAVA or similar server side technologies. Furthermore, by implementing AJAX and the asynchronous HttpRequest( ) call, objects on the screen of the computer 110 are updated dynamically, as soon as the data is available giving a the used a smooth and fast user experience.
As such, the implementation of internal CGI calls and AJAX provides web based calls without affecting the ability of the embedded controller 165 to effectively perform its critical control functions. In addition, the internal functions 320 implement CGI calls as a local function within the context of the worker thread 325, which eliminated the context switch and memory overhead that would normally be associated with the creation of the external shell 340.
The operator interface 105 has been described as having a computer 110. Several types of computing devices can be implemented as the computer 110. One exemplary computing system is now described.
In exemplary embodiments, in terms of hardware architecture, as shown in
The processor 405 is a hardware device for executing software, particularly that stored in memory 410. The processor 405 can be any custom made or commercially available processor, a central processing unit (CPU), an auxiliary processor among several processors associated with the computer 401, a semiconductor based microprocessor (in the form of a microchip or chip set), a macroprocessor, or generally any device for executing software instructions.
The memory 410 can include any one or combination of volatile memory elements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM, etc.)) and nonvolatile memory elements (e.g., ROM, erasable programmable read only memory (EPROM), electronically erasable programmable read only memory (EEPROM), programmable read only memory (PROM), tape, compact disc read only memory (CD-ROM), disk, diskette, cartridge, cassette or the like, etc.). Moreover, the memory 410 may incorporate electronic, magnetic, optical, and/or other types of storage media. Note that the memory 410 can have a distributed architecture, where various components are situated remote from one another, but can be accessed by the processor 405.
The software in memory 410 may include one or more separate programs, each of which comprises an ordered listing of executable instructions for implementing logical functions. In the example of
The web-based operator control interface methods described herein may be in the form of a source program, executable program (object code), script, or any other entity comprising a set of instructions to be performed. When it is a source program, then the program needs to be translated via a compiler, assembler, interpreter, or the like, which may or may not be included within the memory 410, so as to operate properly in connection with the OS 411. Furthermore, the web-based operator control interface methods can be written as an object oriented programming language, which has classes of data and methods, or a procedure programming language, which has routines, subroutines, and/or functions.
In exemplary embodiments, a conventional keyboard 450 and mouse 455 can be coupled to the input/output controller 435. Other output devices such as the I/O devices 440, 445 may include input devices, for example but not limited to a printer, a scanner, microphone, and the like. Finally, the I/O devices 440, 445 may further include devices that communicate both inputs and outputs, for instance but not limited to, a network interface card (NIC) or modulator/demodulator (for accessing other files, devices, systems, or a network), a radio frequency (RF) or other transceiver, a telephonic interface, a bridge, a router, and the like. The system 400 can further include a display controller 425 coupled to a display 430. In exemplary embodiments, the system 400 can further include a network interface 460 for coupling to a network 465. The network 465 can be an IP-based network for communication between the computer 401 and any external server, client and the like via a broadband connection. The network 465 transmits and receives data between the computer 401 and external systems. In exemplary embodiments, network 465 can be a managed IP network administered by a service provider. The network 465 may be implemented in a wireless fashion, e.g., using wireless protocols and technologies, such as WiFi, WiMax, etc. The network 465 can also be a packet-switched network such as a local area network, wide area network, metropolitan area network, Internet network, or other similar type of network environment. The network 465 may be a fixed wireless network, a wireless local area network (LAN), a wireless wide area network (WAN) a personal area network (PAN), a virtual private network (VPN), intranet or other suitable network system and includes equipment for receiving and transmitting signals.
If the computer 401 is a PC, workstation, intelligent device or the like, the software in the memory 410 may further include a basic input output system (BIOS) (omitted for simplicity). The BIOS is a set of essential software routines that initialize and test hardware at startup, start the OS 411, and support the transfer of data among the hardware devices. The BIOS is stored in ROM so that the BIOS can be executed when the computer 401 is activated.
When the computer 401 is in operation, the processor 405 is configured to execute software stored within the memory 410, to communicate data to and from the memory 410, and to generally control operations of the computer 401 pursuant to the software. The web-based operator control interface methods described herein and the OS 411, in whole or in part, but typically the latter, are read by the processor 405, perhaps buffered within the processor 405, and then executed.
When the systems and methods described herein are implemented in software, as is shown in
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
Any combination of one or more computer readable medium(s) may be utilized. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.
In exemplary embodiments, where the web-based operator control interface methods are implemented in hardware, the web-based operator control interface methods described herein can implemented with any or a combination of the following technologies, which are each well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit (ASIC) having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc.
Technical effects include but are not limited to establishing a low-cost web based operator interface with an embedded controller of a generator system. As a web-based system, related software can be installed and maintained with decreased effort. In addition, the exemplary web-based systems and methods described herein reduce an amount of hardware needed in generator systems and shift processing burden from the embedded controller to the operator interface. In addition, the systems and methods described herein ease downloading of new web pages to the embedded controller. As such, where new control sub-systems are added to the generator control system (such as static or rotating field exciters and static starters) which needs to be controlled or monitored, web pages can be easily downloaded into the embedded controller without modifying existing setup or shutting down the generator control system. In addition, with web-based communication, multiple operator interfaces can concurrently fetch the data from the generator control system both locally and remotely. The web-based systems and methods described herein enable platform independence. As such, there is no software or hardware dependency as only web browser needs to run the web pages, which allows the system to run on scalable platforms to allow tradeoffs in cost and functionality.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
