Patent Application
20160380444
The invention relates to the management of the production of an energy system comprising an energy production device, or energy source, a plurality of energy storage modules and a control device intended to control the storage of energy and the production of energy output by the system.
Certain energy production systems, or plants, produce energy, for example electric energy, by means of conversion of a renewable energy such as solar energy or wind energy. The electric energy produced is supplied to an electric power supply network. Renewable energy is most often of an intermittent nature: it is not continuous or uniform over time. It may be necessary or useful to control the production of electric energy output by the system, or the plant, with the aim for example of ensuring the stability of the electric power network or supplying the electric energy produced during a pricing period which is favourable for the system or plant operator. In order to ensure a certain flexibility as regards the production of energy by the upstream energy production device (photovoltaic modules, wind modules, etc.) and the production of energy output by the system, the latter incorporates energy storage modules. During operation, the energy production device produces electric energy depending on the quantity of renewable energy received. This electric energy is either directly supplied to the electric power network or provisionally stored by the storage modules and then further supplied to the electric power network.
In order to better manage the storage of the energy and the production thereof output by the system, operation of the system is generally pre-programmed by means of an energy production plan. This production plan is established on the basis of the hypothetical production of energy by the source. It covers a reference time period, for example 24 hours, and is intended to be applied during a corresponding future period. The production plan is defined by:
During operation, the storage of energy and the production of energy output by the system are controlled on the basis of this production plan.
During the working life of the energy production system, it may prove necessary to carry out certain further operations, in addition to the normal operation of the system, in particular on the storage modules. These complementary further operations, which we called “related operations”, may comprise tests, calibration, maintenance operations, balancing operations, or other operations.
At present, these related operations are carried out either “off-line” on at least part of the production plant, which is disconnected and therefore does not participate momentarily in the overall energy production, or “on-line” (namely during energy production) in an opportune manner if a favourable situation arises and a related operation may be carried out.
The present invention aims to improve the situation.
To this end, the invention relates to a method for managing, by means of a management device, the energy production of an energy system incorporating an energy production device and a plurality of energy storage modules, comprising a step for formulation, by the management device, of a forecast plan for production of energy output by the system for a future period, characterized in that it comprises a step for incorporation, by the management device, of at least one related operation on a storage module in the production plan of the system.
As a result of the invention, during energy production by the production system on the basis of the established production plan, one or more related operations are carried out on one or more storage modules, the latter also participating in the overall production of the system.
Advantageously, the incorporation, in the production plan, of a related operation on a storage module comprises the formulation of a forecast plan for operation of the storage module containing setting to an initial state of charge required for the related operation, a step for execution of a power profile of the related operation and stoppage of the said execution step when a criterion for stoppage of the related operation is satisfied.
Again advantageously, the method comprises a step of recording at least one related operation profile in a database of the management device, the said profile containing an initial state of charge required for the storage module, a power profile comprising data relating to the power time trend of the storage module, and a criterion for stoppage of the related operation.
According to a first embodiment, the step of formulation of a production plan and the step of incorporation of at least one related operation on a storage module in the production plan of the system are performed in a combined manner.
According to a second embodiment, the step of incorporation of at least one related operation on a storage module in the production plan of the system is performed after the step of formulation of a production plan.
Advantageously, the step of formulation of a production plan and the step of incorporation of at least one related operation on a storage module in the production plan are performed by the management device via execution of an optimization software.
In this case, again advantageously, the method comprises a step of specification of functions to be optimized, at least one of the functions being to incorporate at least one related operation in the operation of at least one storage module.
In a particular embodiment, the incorporation of a related operation on a storage module is achieved by performing charging or discharging compensation with at least one other storage module.
In another particular embodiment, the incorporation of a related operation on a storage module is performed by modification of a pre-established production plan within a given tolerance margin.
The related operation may be an operation of the group comprising the related operation is one of the operations from the group comprising:
In one particular embodiment, the energy production device is of the intermittent type and the production plan is established on the basis of an estimate of energy production by the energy production device during the future period.
The invention also relates to a device for managing an energy production system incorporating an energy production device and a plurality of energy storage modules, comprising a tool for formulation of a forecast plan for production of energy output by the system for a future period, characterized in that the tool for formulation of the production plan comprises a module for incorporation of at least one related operation on a storage module in the production plan of the system.
Advantageously, the incorporation module is designed to formulate a forecast plan for operation of the storage module containing setting to an initial state of charge required for the related operation, a step for execution of a power profile of the related operation and stoppage of the said execution step when a criterion for stoppage of the related operation is satisfied.
Again advantageously, it comprises a database for storing at least one related operation profile, the said profile containing an initial state of charge required for the storage module, a power profile comprising data relating to the power time trend of the storage module, and a criterion for stoppage of the related operation.
The invention will be better understood with the aid of the following description of a particular embodiment of the method for managing the energy production of an energy system and a management device for implementing the method, with reference to the attached drawings in which:
The upstream energy production device 2 comprises N energy source(s), with N≧1. In this case, the device 2 comprises N energy sources able to convert a first energy such as a renewable energy (solar energy, wind energy, or the like) into a second energy, for example electric energy. The energy produced by the energy sources is here temporarily intermittent, which means that it is not constant and uniform over time. In the example of embodiment described here, the energy production device 2 comprises N photovoltaic modules which are connected together and intended to convert solar energy into electric energy. The energy production device 2 is referred to as being “upstream” since it produces the energy upstream of the energy production output 6 of the system 1.
The system 1 comprises M energy storage devices 3A-3D, here batteries, with M greater than 1. In the example shown here, M is equal to 4. These M storage devices 3A-3D are connected by means of an electrical connection 5 to the energy production device 2.
The system 1 comprises an output 6 which is connected to an electric power network 10 and via which the system 1 is intended to introduce electric energy into the network 10. The upstream energy production device 2 and the energy storage modules 3A-3D are respectively connected to the output 6 by two respective electric connections 8 and 9.
The upstream energy produced by the device 2 is either directly supplied to the electric power network 10 via the output 6 of the system 1 or provisionally stored in the storage modules 3A-3D of the system 1, as will be explained further below.
The management device 4 is intended to manage storage of the electric energy produced by the upstream production device 2 and the production of electric energy at the output 6 of the system 1. The energy storage and the production of energy at the output 6 of the system 1 (otherwise referred to as the introduction of electric energy into the electric power network 10) are controlled by the management device 4 on the basis of a production forecast plan.
The production forecast plan is formulated by a tool 40 of the management device 4. It covers a reference time period, for example 24 hours.
The production forecast plan corresponds to a desired or target operation of the energy production system 1 during a future period corresponding to the reference period which here covers 24 hours. It comprises:
A certain tolerance margin may be defined with regard to the set production power levels and the set states of charge of the storage modules. For example, the tolerance margin may be + or −5% of the set power for the power plan or + or −5% of the set state of charge.
The production plan is established on the basis of data relating to an estimate of electric energy production by the energy production device 2 during a future time period corresponding to this reference period.
The graph “px” shown as a broken line in
The method for managing the energy production according to the invention comprises a first step E0 of recording data, “data _Pest”, relating to the estimate of the electric energy production by the energy production device 2 during the reference period, in a database 11 of the management device 4. The data “data_Pest” may be entered by a user via a user interface of the management device 4 which stores them in the database 11.
According to the invention, the method for managing the production of the system 1 comprises a step of incorporating related operations on storage modules 3A-3D in the production plan, as will be explained further below. A “related operation on a storage module” is an operation where the storage module is required to perform one or more actions having an aim other than that of contributing to the production of energy by the system 1. This different aim may be in addition to or instead of the aim of contributing to produce energy at the output of the system 1. A related operation on a storage module may be a (complete or partial) charging test and/or (complete or partial) discharging test, a balancing operation, a maintenance operation or any other operation affecting the storage module.
A related operation is characterized by different elements comprising:
The method for managing the energy production according to the invention comprises a second step E1 of recording a set of related operation profiles in a database 12 of the management device 4. Each related operation profile contains the characteristic data relating to this operation, “data-OPcon”, mentioned above. The data, “data-OPcon”, may be entered by a user via the user interface of the management device 4 which stores them in the database 12.
A rest step is a step during which the storage module is inactive, its charging or discharging power being zero.
The method also comprises a step E2 of recording data relating to the trend of the price of the electricity during the reference period. This price data “data-px” is modelled by the graph px in
The method also comprises a step E3 of recording data relating to the storage modules “data_batt”. The storage modules, or batteries, 3A-3D, are represented by a set of characteristic data comprising here a maximum (charging or discharging) power, a storage capacity and an initial state of charge. The data relating to the storage modules is stored in the database 11 by the management device 4, for example after being entered by a user or obtained from a test carried out on the module.
The data relating to the estimate of the energy production Pest, the data relating to the storage modules 3A-3D and the data relating to the price of the electricity represent constraints which may be taken into account during the formulation of a production plan of the system 1 by means of optimization.
The method also comprises a step E4 of specifying one or more functions to be optimized to the tool 40 for formulating a production plan. “Functions to be optimized” is understood as meaning an object to be achieved by the system 1 during the production of energy in accordance with the production plan. For example, the following functions may be specified:
In this case, it is desired that the system 1 should produce energy at the output 6 so as to maximize the gain on sale and perform one or more related operations on one or more storage modules, by means of execution of the production plan during a future period corresponding to the reference period.
Instead of the function b), any other function aiming to incorporate at least one related operation in the operation of one or more storage modules could be specified. For example, the function may be to specify the carrying out of at least one related operation on each storage module.
It is also possible to add the function of maximizing the overall economic value of the related operations incorporated. As explained above, each related operation is associated with an economic value indicating the advantage of carrying out this related operation on an economic level. If several related operations are incorporated in the production plan, the respective economic values of these operations are added together to obtain an overall economic value. In this case, the function is to maximize the overall economic value of the related operations incorporated.
In another example of embodiment, the target function is to carry out a specific related operation specified for one or more particular storage modules, for example following an accident or a production fault.
In any case, in the step E4, the tool 40 of the management device 4 records one or more target functions to be optimized, one at least of these functions being to incorporate at least one related operation in the operation of one or more storage modules. The functions may be specified by a user via the user interface of the management device 4.
During a step E5, the tool 40 of the management device 4 formulates a production plan for the system 1. This production plan is formulated by an optimization process which consists in determining an optimum solution for the function(s) specified during the step E4 taking into account certain constraints. The constraints comprise here the estimation of the power Pest produced by the photovoltaic modules, the price trend of the electricity and the characteristics of the storage modules.
The formulation E5 of the production plan of the system 1 by the management device, as described, incorporates, in a combined manner, at least one related operation on a storage module in the production plan of the system. Thus the formulation of the production plan and the incorporation of one or more related operations on one or more storage modules are performed at the same time. The production plan is formulated incorporating therein one or more related operations on one or more storage modules. In order to incorporate a related operation on a storage module in the production plan, the management device 4 formulates an operation plan for the storage module, including setting to the initial state of charge required for the related operation, a step for execution of the power profile of the related operation and stoppage of the said execution step when a criterion for stoppage of the related operation is satisfied.
An example illustrating a given production plan is shown in
During formulation of the production plan, the management device 4 breaks down the overall power plan of the storage modules into the respective individual contributions of the different storage modules 3A-3D. These contributions are represented by individual charging or discharging zones which respectively relate to the different storage modules, as indicated by the key in
Each of
The related operations planned on the storage modules are then carried out during operation of the production system 1, during the course of production based on the established production plan.
In the above description, the incorporation, in the production plan, of the related operations on the storage modules is performed by the management device 4 during formulation of the production plan. By way of a variant, the related operations are incorporated in the production plan afterwards, once the production plan has been established. In this case, in order to incorporate a related operation in the operation of a storage module, the method comprises a step of searching for the specific characteristics of this related operation in the power and state-of-charge plans of the storage module considered. The specific characteristics of the related operation comprise here an initial state-of-charge of the storage module, a power (charging and discharging) profile and a criterion for stoppage of the operation, as explained above.
The method also envisages incorporating a related operation on a storage module by performing charging or discharging compensation with at least one other storage module. For example, it can be seen in
The method may also envisage modifying the production plan within a given tolerance margin in order to facilitate incorporation of a related operation in the production plan.
With reference to
The tool 40 comprises an optimization software such as AIMMS®.
Moreover the management device 4 comprises a central control unit 47 to which all the elements 11, 12, 40 to 46 are connected and which is intended to control operation of these elements.
| Number | Date | Country | Kind |
|---|---|---|---|
| 15 55762 | Jun 2015 | FR | national |
