Order for a hybrid power plant comprising a power generation source and a storage system

Abstract

This presentation concerns a method for controlling a hybrid power plant (100) comprising a power generation source (2) and an energy storage system (3). The method includes determining a power setpoint to be supplied by the source and the storage system, taking into account: - the dynamics of the source; - the state of charge of the storage system; and - extreme values ​​that can be taken by an instantaneous control value of the source, imposing a rate of change of a power value of the source; and - control of the source and the storage system by the setpoints. Figure for the abstract: Fig. 1

Description

Title of the invention: Control of a hybrid power plant comprising a power generation source and a storage system technical field

[0001] This presentation relates generally to the production of electrical energy and more specifically to the management systems of hybrid power plants. STATE OF THE TECHNOLOGY

[0002] Combined cycle gas turbine power plants are known. They consist of a combustion turbine that can respond quickly to electricity demand and a steam turbine with a slower operating dynamic. A power reserve can be associated with the power plant, and it is usually operated below this reserve. When the grid operator wishes to draw on this reserve, it sends a signal to regulate the frequency of the electrical grid. This signal represents the desired rate of change from an operating point corresponding to the sale of the energy to be produced by the generating source itself to a second operating point corresponding to the sale of energy and the absorption or transmission of all or part of the reserve.The grid operator requests that producers participating in secondary frequency control modulate their power output around their production point linked to energy sales. This power modulation is achieved via a frequency control signal that the operator sends to the producers, who then multiply this signal by the reserve volume they dedicate to secondary control. Since this signal is between -1 and 1, the power plants must therefore modulate their output by decreasing or increasing it up to the maximum of their contracted reserve. If the frequency control signal is 0, the target power output remains the same as the production schedule linked to energy sales.

[0003] However, the dynamics of an electricity generation source include an "inertia" that does not always allow it to meet the power variation rate requirement imposed by the grid operator. In such a case, the generation source may be limited in its ability to vary its power sufficiently rapidly. Thus, this type of power plant is limited by the dynamics of the steam turbine, which therefore prevents it from following the setpoint imposed by the grid operator.

[0004] To remedy this, the operating point related to energy sales can be reduced to ensure the release of the reserve within the allotted time by freeing up margin on the combustion turbine. This principle is called "derating". But, in the While practical, this solution presents a significant drawback and cost for the power plant. The disadvantage of this reduction in power output is that it effectively limits the generation available for sale when the plant participates in secondary control. This is the case, for example, with a combined-cycle gas turbine (CCGT) power plant with a maximum capacity of 500 MW, which can provide a maximum reserve power of 100 MW over 300 seconds. In other words, the maximum upward or downward slope the plant can follow is 20 MW / min. To provide the maximum reserve power for this secondary control, a 20 MW reduction is necessary (this reduction is determined by the steam turbine's delay over 600 seconds). The power available for sale has therefore decreased by 20 MW.Thus, assuming that this power plant operates 5,000 hours per year, including 2,000 hours with secondary frequency control, this derating represents a production loss of approximately 40 GWh, or 1.7% of the plant's annual production. Considering a contribution margin of €10 / MWh, this represents a loss of €400,000 per year.

[0005] Energy storage systems can also be integrated into the electricity generation system to compensate for the inertia of the electricity generation source without limiting its operation. In the example of a 500 MW combined cycle gas turbine power plant, battery storage with a capacity of 20 MW can complement the slow dynamics of the steam turbine. This has the advantage of eliminating the 20 MW derating by increasing the reserve (110 MW instead of 100 MW) as well as the operating point related to energy sales by 10 MW.Furthermore, the battery's energy capacity can be optimized by simulating hybridization and activation for secondary frequency regulation. In our example, a 20 MWh battery is sufficient. However, if other services are anticipated, they may be more limiting for the battery's capacity.

[0006] A first control solution for this hybrid power plant consists of using a control device that guarantees the dynamics imposed by the grid operator for tracking the frequency regulation signal. The device "limits" the signal to match the dynamics of the electricity generation source and requests the missing amount of energy from the storage system in order to comply with the operator's setpoint.

[0007] However, this solution is not sustainable. Indeed, over time, the state of charge of the energy storage system decreases to reach a zero value, thus compromising the ability of the hybrid power plant to provide the service over time. GENERAL STATEMENT

[0008] One aim of the present exposition is to improve the control of power plants hybrids.

[0009] To this end, a method for controlling a hybrid power plant is proposed, according to a first aspect.

[0010] the process comprising at least once the implementation of the following steps:

[0011] - considering a power setpoint of the power plant and an instantaneous value current control of the power plant

[0012] the current instantaneous control value of the power plant imposing a rate of change of a power value of the power plant,

[0013] the setpoint and the current instantaneous value intended to compensate for a difference between a frequency of an electrical network and a nominal frequency of the network,

[0014] determination of an activation setpoint for a reserve power of an electrical production source of the power plant from a measured value of a state of charge of an energy storage system of the power plant and taking into account a minimum value and a maximum value that can be taken by a subsequent instantaneous control value of the power plant,

[0015] the reserve power of the source being a predetermined power margin of the source,

[0016] the minimum and maximum values ​​being a function of the current instantaneous control value of the power plant and a predetermined threshold for the rate of change of the current instantaneous control value of the power plant,

[0017] the activation command being between a first terminal and a second terminal,

[0018] the first and second terminals being a function of a maximum power available in the storage system, the reserve power of the power plant, the reserve power of the source, the current instantaneous control value of the power plant, the minimum and maximum values ​​and a power variation rate threshold of the source;

[0019] - based on the activation command for the reserve power of the source and a reserve power of the power plant, determination of a current instantaneous control value for the source,

[0020] the current instantaneous control value of the source imposing a rate of change of a power value of the source,

[0021] the reserve power being a predetermined power margin of the power plant;

[0022] - from a power setpoint outside the reserve of the source and the ins value current tantanate control of the source, determination of a power setpoint to be supplied by the source,

[0023] the power outside reserve of the source corresponding to the power supplied by the central unit which does not contribute to the frequency adjustment;

[0024] - from a measurement of the power supplied by the source and the setpoint of power of the power plant, determination of a power setpoint to be supplied by the storage system by compensating for a difference between the power supplied by the source and the power setpoint of the power plant; and

[0025] - control of a power supplied by the source and a power supplied by the storage system respectively from the power setpoint to be supplied by the source and the power setpoint to be supplied by the storage system.

[0026] Thus, such a control method makes it possible to comply with the instructions of the network manager and the dynamics of the electricity production source while maintaining the state of charge value at an acceptable level for the batteries.

[0027] It also has the advantage of preserving the previous configuration of the hybrid power plant control device by only modifying the instructions.

[0028] It can be provided that the process is implemented such that the first and second bounds are determined respectively by the following expressions: ^Pr'jm'n ~ Pr~ ( 1 " N [ ) ' Pr~ Ps^nax ' C-Pr'jnax ~ “P > + (1 + 'Pr + Psmax' with Cpr'jnjn the first terminal and Cpr'ma!( the second terminal, Psjnax the maximum power available in the storage system, Pr the reserve power of the power plant, Pr' the reserve power of the source, and Nj the current instantaneous value.

[0029] It may be provided that the method further includes a calculation of a second activation setpoint for the reserve power of the source for the subsequent instantaneous value,

[0030] the method being implemented so that a slope value between a first point corresponding to the activation setpoint calculated for the current instantaneous value and the activation setpoint calculated for the subsequent instantaneous value is bounded, for example by filtering, in order to respect the power rate of change threshold of the source.

[0031] It may also be provided that the process is implemented so that a minimum limit of the state of charge is equal to a fraction, for example 40%, of the total capacity of the storage system and that a maximum limit of the state of charge is equal to a fraction, for example 60%, of the total capacity of the storage system,

[0032] and so that the activation setpoint of the reserve power of the source is equal, if the measured value of the state of charge is strictly greater than the maximum limit, to the first terminal and, if the measured value of the state of charge is strictly less than the minimum limit, to the second terminal.

[0033] The minimum limit and the maximum limit are state of charge values.

[0034] It may also be provided that the process is implemented so that the current instantaneous value aims to deliver the reserve power in less than 300 seconds, the current instantaneous value being between -1 and 1.

[0035] It may be provided that the method is implemented so that the current instantaneous value aims to deliver the reserve power of the power plant in less than 30 seconds to compensate for the difference between a frequency of an electrical network and a nominal network frequency,

[0036] a nominal network frequency value equal to 50.0 Hz and a value of the same deviation equal to -200 millihertz,

[0037] the current instantaneous value being proportional to the same deviation.

[0038] It may further include a saturation step of the current instantaneous control value of the source.

[0039] According to a second aspect, a control device for a hybrid power plant is proposed, the device being configured to implement a process according to the first aspect.

[0040] According to a third aspect, a computer program product is proposed comprising instructions which, when the program is executed by a computer, lead the computer to implement a process according to the first aspect.

[0041] According to a fourth aspect, computer-readable storage means are proposed, on which a computer program product according to the third aspect is recorded.

[0042] According to a fifth aspect, a hybrid power plant is proposed comprising: - a control device for the hybrid power plant conforming to the second aspect; - a source of electricity production; and - an energy storage system, the production source and storage system being configured to be controlled by the control device. DESCRIPTION OF THE FIGURES

[0043] Other features, purposes and advantages will become apparent from the following description, which is purely illustrative and not limiting, and which should be read in conjunction with the accompanying drawings on which:

[0044] Fig. 1 schematically illustrates an example of a power plant architecture, detailing the inputs and outputs;

[0045] [Fig.2] is a flowchart illustrating a method of implementing a control process for a hybrid power plant;

[0046] [Fig.3] illustrates an example of a causal simulation model of a hybrid power plant control device;

[0047] [Fig.4] illustrates another example of a causal simulation model of a hybrid power plant control device;

[0048] Figure 5 illustrates the causal model of Figure 4 in a particular case,

[0049] Figure 6 illustrates the causal model of Figure 4 in another specific case,

[0050] [Fig. 7] illustrates the causal model of [Fig. 4] in a particular case different from figures 5 and 6;

[0051] [Fig.8] illustrates a variant of the causal model of [Fig.4];

[0052] [Fig.9] illustrates a simulation result of the control device of [Fig.4] activated by a setpoint imposed by the network manager in a first case; and

[0053] Figure 10 illustrates a simulation result of the same control device activated by a setpoint imposed by the network operator in a second case. DETAILED DESCRIPTION

[0054] Schematically represented in [Fig.1] as an example is a hybrid power plant 100 composed of an electricity production source 2 and an energy storage system 3, each power supplied P', Ps being controlled by a control device 1.

[0055] The electricity production source 2 can, for example, be a combined cycle gas power plant comprising a combustion turbine and a steam turbine, a conventional gas, oil or coal power plant, a nuclear power plant or a hydroelectric power plant.

[0056] The energy storage system 3 can be a set of batteries, or even a battery or any other storage means configured to power an electrical network.

[0057] In this description, we consider the case where the hybrid power plant increases or decreases (also referred to as absorption) the power P it supplies to the electrical grid in order to regulate the grid frequency. That is to say, the power supplied increases or decreases to compensate for a deviation in the grid frequency previously set, for example, at 50 Hz by the grid operator in France or Europe. The relationship between the power supplied by the power plant and its ability to influence the grid frequency is known and will not be detailed further.

[0058] However, it may be stipulated that the power plant must deliver this power within a given timeframe. A dynamic constraint may therefore be imposed on the power plant, particularly by the operator.

[0059] For example, in France, a control unit 100 participating in secondary frequency regulation is configured to deliver this power in less than 30 seconds in order to to compensate for a frequency difference of -200 MHz. According to another example, this power is delivered in less than 300 seconds.

[0060] In order to respect the imposed dynamics, it is planned that the control device 1 will implement a process whose implementation steps are illustrated as an example in [Fig.2].

[0061] In what follows, the present exposition will be detailed for a power supplied by the power plant to compensate for the difference and applies mutatis mutandis to the case where the difference is compensated by a power absorbed by the power plant.

[0062] Consider a power setpoint CP of the central unit and a current instantaneous value Ni of the central unit control.

[0063] The current instantaneous value Ni imposes a rate of change of a power value of the power plant from a current operating power to the setpoint and aims to compensate, together with the setpoint, for the aforementioned deviation. This can also be referred to as a deviation.

[0064] Therefore, the CP instruction can be represented by the following equation:

[0065] Cp — Po + Ni' Pr

[0066] with:

[0067] Po representing an out-of-reserve power of the source, and

[0068] Pr representing a reserve power of the power plant which are predetermined data finished.

[0069] The off-reserve power Po corresponds to power supplied for a service other than frequency regulation. For example, the off-reserve power corresponds to what the power plant supplies to feed the network. This power therefore does not contribute to frequency regulation.

[0070] The reserve power Pr of the power plant corresponds to a power margin intended for other services such as frequency regulation. It is therefore defined, in particular, as a margin between the non-reserve power and the nominal power corresponding to the maximum power the power plant is capable of supplying, and thus depends on the power plant's construction specifications. In the present application, this definition may apply to other reserve power levels, in particular the reserve power Pr' of source 2.

[0071] It is then understood that the dynamics followed by the power plant are imposed by the current instantaneous value Ni at each instant.

[0072] These values ​​also constitute over a period a signal, known as a "remote tuning signal", or even a "frequency tuning signal".

[0073] For example, in France, this signal is between -1 and 1. Over a given period, it can be divided into several linear segments of negative or positive slope.

[0074] Therefore, it is further understood that the power supplied or absorbed by the power plant to compensate for the frequency difference is defined by the product N; ■ Pr. Indeed, at each instant, the value Ni depends on the difference and its product with the value of the reserve power amounts to determining at that instant what proportion of the reserve power is to be supplied or absorbed to compensate for the difference.

[0075] Therefore, it is necessary to implement a power plant control strategy which aims to determine the respective power shares of source 2 and storage system 3. To determine these shares, consideration is given to the dynamics imposed by the manager but also to those imposed naturally by source 2, for example for the combined gas power plants mentioned above in this description which may exhibit an inertia compromising the ability of the power plant to follow the imposed dynamics.

[0076] It is also assumed that the state of charge (SOC) of the energy storage system 3 is continuously measured so as to transmit this information to the control device 1. The state of charge (SOC) is characterized by a predetermined minimum limit (SOCmin) and a predetermined maximum limit (SOCmax). These limits define boundaries within which the state of charge (SOC) must remain in order not to compromise the hybrid power plant's ability to provide service over time.

[0077] The minimum limit SOCmin and the maximum limit SOCmax are parameters for maintaining the state of charge of the energy storage system 3.

[0078] Thus, according to one embodiment, the minimum limit SOCmin is 40% of the total capacity of the energy storage system 3 and the maximum limit SOCmax is 60% of this total capacity.

[0079] According to another embodiment, the minimum limit SOCmin can reach 20% of the total capacity and the maximum limit SOCmax can reach 80% of the total capacity.

[0080] During a step El, the activation setpoint for the reserve power of a power generation source of the plant is determined from a SOC value measured from a state of charge of the plant's storage system.

[0081] In the development of this instruction, a minimum value and a maximum value that can be taken by a subsequent instantaneous value Ni+i of the control unit are also taken into account.

[0082] These minimum and maximum values ​​are determined based on the current instantaneous value Ni of the control unit and a predetermined threshold for the rate of change of this current instantaneous value. This threshold is, for example, determined in advance by the dynamics imposed by the controller, which will influence the slope of the remote control signal.

[0083] To achieve this, the activation setpoint is between a first limit C^ min and a second limit Cpr'>max given by the following equations: [°°841 CP,m = Pr-(X-Ni}-Pr-P!l„x [00851 cP,„a= - pr+ (i+A',)-p;+pvm

[0086] with Ps>max representing the maximum power available at the level of the energy storage system 3.

[0087] Thus, for a state of charge SOC above its maximum limit SOCmax, the minimum value for the setpoint can be chosen:

[0088] CPr=CFrJ,lln

[0089] For a state of charge SOC below its minimum limit SOCmin, the maximum value for the setpoint can be chosen:

[0090] Cpr = Cp^nax

[0091] Otherwise, when the state of charge is within this range, the setpoint is given by:

[0092] Cp^NP,.

[0093] According to another embodiment, it is possible to fix intermediate points between the two terminals in order to slow down the charging and discharging of the batteries and to reduce the use of storage.

[0094] Of course, the terminals can be adapted for different dynamic constraints of the electrical production source 2 and the manager as well as for other settings or services.

[0095] During an Eli step, a second activation setpoint for the reserve power of the source is calculated for the subsequent instantaneous value.

[0096] Therefore, in the calculation of the first and second bounds, it is taken into account that a slope value between a first point corresponding to the activation setpoint CPr' calculated for the current instantaneous value and the activation setpoint calculated for the subsequent instantaneous value is bounded, for example by filtering, in order to respect the power variation rate threshold of the source.

[0097] During a step E2, an instantaneous current value Ni' of the source 2 is determined from the setpoint and the reserve power of the power plant, for example by dividing the setpoint by the reserve power of this power plant 100.

[0098] The frequency adjustment signal of the source N' is then distinguished by its amplitude and its slope compared to the frequency adjustment signal of the central unit N.

[0099] During a step E21, the current instantaneous value Ni' of the source 2 is saturated. Thus, the current instantaneous value of the source is bounded within a domain identical to that of the instantaneous value of the power plant previously defined by the network operator.

[0100] During a step E3, a power setpoint CP' to be supplied by the source 2 is determined from the source's out-of-reserve power and the current instantaneous control value Ni' of the source. This determination takes place, for example, according to the following equation:

[0101] C^Pç+Nt-P,

[0102] During a step E4, a power setpoint CPs to be supplied by the storage system 3 is determined from a measurement of the power P' supplied by the source 2 and the power setpoint CP of the power plant so as to compensate for a difference between the power supplied by the source and the power setpoint CP of the power plant.

[0103] For example, the power setpoint CPs can be expressed by the following equation:

[0104] CP=Cp-P'

[0105] Thus, the power setpoint CPs is defined as the difference between the value corresponding to what the electrical production source 2 supplies and the value of the power P' that the source 2 actually supplied, measured at its output.

[0106] During a step E5, the powers supplied by the source and by the storage system are controlled by the control device respectively from the setpoint of power to be supplied by the source and by the storage system.

[0107] It is observed that the preceding equations are parameterized for an example of frequency control but can be adapted for any other type of frequency control or hybrid power plant, in particular according to the dynamic capabilities of the source and the power available by the storage system.

[0108] Thus, the presented process makes it possible to comply with two constraints while respecting the requirements imposed by the manager at any given time, namely:

[0109] - the dynamics of the electrical production source 2; and

[0110] - maintaining the state of charge (SOC) of the storage system 3 in AC terminals acceptable.

[0111] Furthermore, to ensure that the state of charge (SOC) remains within the two limits, the control strategy implemented by the process steps takes into account extreme cases of remote control signal evolution. Indeed, the applicant has identified these values ​​as particularly critical because, to ensure that the storage system does not empty over time, it is not enough to simply ensure that the state of charge is maintained between its limits at every instant; it is also necessary to anticipate these extreme cases.

[0112] In this case, another control strategy not taking extreme cases into account is illustrated as an example in [Fig.3] by a causal simulation model.

[0113] In the present description, a causal model is a representation relating input and output flows of the model by means of blocks that generally contain mathematical operations. The input flows are then modified into intermediate flows by the blocks until the output flows are obtained. Thus, it is It is possible to visualize the input and output flows, but also each intermediate flow.

[0114] In this example:

[0115] - block 10 limits the slope of the first derivative of the frequency adjustment signal input N between two terminals, in this example, 0.003 and -0.003, in order to obtain the output signal N', and

[0116] - at the output of block 8, the flow contains the product between Pr and N received at the input, and

[0117] - at the output of block 7, the power Ps of the energy storage system 3 contains the difference between the power setpoint CP of the power plant and the power supplied by the source P'.

[0118] However, the applicant has observed through this simulation that such a control strategy taking into account only the state of charge SOC is insufficient and inevitably leads to a depletion of the energy stored in the storage system 3.

[0119] We will now therefore present examples obtained by simulation of the process described above which makes it possible to overcome this exhaustion problem and, more generally, to highlight the aforementioned advantages. EXAMPLES

[0120] Consider a hybrid power plant 100 with a reserve power Pr of 110 MW, comprising an electricity production source 2 materialized by a 500 MW combined cycle gas power plant whose dynamics are limited in increase or decrease to 20 MW per minute and an energy storage system 3 materialized by a 20 MW battery whose initial state of charge SOC is for example between 40% and 60% of the total capacity of the energy storage system 3.

[0121] The power demand P' of the electrical production source 2 is described by the following equation:

[0122] P' = Po+HO-Æ

[0123] Suppose that the network operator wishes to call upon the reserve power of the hybrid power plant Pr, amounting to 110 MW, for secondary frequency regulation in Europe. In other words, the reserve must be fully delivered within a maximum of 300 seconds.

[0124] The target power limits for activating the reserve for the electricity production source are thus expressed as follows:

[0125] CPrmax- -110+ (1 + Æ) ■ 100+20

[0126] and [°1271 CPr^ 110-100-(1-2V)-20

[0128] The power setpoint of the CPS storage system is expressed as follows:

[0129] CP^PO+1W-NP'

[0130] Starting from the simulation model of the prior control device 1 which does not allow the state of charge of the energy storage system 3 to be maintained, illustrated in [Fig.3], a new causal simulation model which allows this problem to be solved is illustrated in [Fig.4].

[0131] This simulation model is representative of the implementation of the steps of the control process described above over several iterations.

[0132] This model includes:

[0133] constant simulation inputs referenced 5,

[0134] variable simulation inputs referenced 6,

[0135] of the blocks referenced 7 corresponding to the operations of addition and subtraction between streams containing the values ​​determined upstream in order to obtain downstream the values ​​obtained by these blocks,

[0136] referenced blocks 8 corresponding to the multiplication and division operations between streams containing the values ​​determined upstream in order to obtain downstream the values ​​obtained by these blocks,

[0137] of the simulation outputs referenced 9, and

[0138] a slope limiter block 11 applying to the value of the first derivative (in other words, the slope) of the setpoint Ca for activating the reserve power of the source in order to respect the threshold of the rate of change of power of the source.

[0139] Blocks 12 and 13 are also included, which are tests on the state of charge (SOC) of the energy storage system 2. If the state of charge (SOC) is below its minimum limit (SOCmin), then the output flux of block 12 is 1; otherwise, it is 0. If the state of charge (SOC) is above its maximum limit (SOCmax), then the output flux of block 13 is 1; otherwise, it is 0. Finally, the simulation model also includes block 14, which is a NOR function. When both fluxes take the value zero, then the state of charge (SOC) is between its minimum limit (SOCmin) and its maximum limit (SOCmax).

[0140] Figure 5 illustrates the set of active flows of the causal model in the case where the state of charge SOC is between its minimum limit SOCmin and its maximum limit SOCmax.

[0141] the flow 15 contains the product of the instantaneous control values ​​N of the power plant with the reserve power of the power plant Pr after application of a block 7,

[0142] the flow 16 contains the flow 15 limited in slope by application of block 11 and divided by the reserve power of the power plant Pr after application of a block 8, and

[0143] the stream 17 contains the CPS power supplied by the storage system after application of blocks 7 and 8 to the variable inputs N, P', Po and to the constant input Pr so as to obtain the equation CPS = Po + 110 ■ N - P'.

[0144] Figure 6 illustrates the set of active flows of the causal model in the case where the state of charge SOC is above its maximum limit SOCmax:

[0145] the flow 18 contains the first bound CPrmin by application of blocks 7 and 8 to the variable input N and to the constant inputs Ps>max, Pr so as to obtain the equation ^,= 110-100-(1-^)-20,

[0146] the flow 19 is obtained in a manner analogous to that for the flow 16, and

[0147] the flow 20 is obtained in a manner analogous to that for the flow 17.

[0148] Figure 7 illustrates the set of active flows between the output and the input in the case where The state of charge (SOC) is below its minimum limit (SOCmin):

[0149] the flow 21 contains the second limit CPr max by applying blocks 7 and 8 to the variable input N and the constant inputs Ps>max, Pr so as to obtain the equation CPr,m = -110+(l + V)-100 + 20,

[0150] the flow 22 is obtained in a manner analogous to that for flows 16 and 19, and

[0151] the flow 23 is obtained in a manner analogous to that for flows 17 and 20.

[0152] Figures 9 and 10 illustrate results obtained by visualizing the outputs at different levels of the causal model.

[0153] In particular, these figures show the instantaneous control value N of the power plant (curve 24) and the instantaneous control value N' of the source (curve 25), the state of charge SOC (curve 26), the power Ps supplied by the storage system (curve 27), the minimum limit SOCminde of the state of charge SOC of the storage system 3 (curve 28), the first terminal CPr ' in (curve 32) and the second terminal CPrmiiX (curve 31) after slope limitation by block 11, as well as the respective parts of the power setpoint CP of the power plant (curve 29) and the power setpoint C p- of the source (curve 30) useful for frequency adjustment.

[0154] On [Fig.9], the state of charge SOC of the energy storage system 3 is between its maximum limit SOCmax and its minimum limit SOCmin, and the output frequency control signal N' follows the input frequency control signal N with an offset corresponding to the slope limit allowing compliance with the dynamics of the power generation source 2.

[0155] In [Fig. 10], the state of charge SOC of the storage system 3 is below its lower limit SOCmin, which requires a power input from the electricity production source 2 so that the storage system 3 can recharge according to the maximum limit CPr >max of the activation setpoint of the reserve power of the source 2

[0156] Thus, the results illustrated in Figures 9 and 10 confirm that the process stated above allows the storage unit 3 not to deplete the stored energy over time.

[0157] A variant of the simulation model of [Fig. 4] is illustrated in [Fig. 8]. Compared to the model of [Fig. 4], it further includes a saturation block 24 interposed between the flows 25 and 26 so as to have the same characteristics as the frequency control signal N sent by the network operator. In other words, in order for the flow 26 to be between -1 and 1, the flow 25 is saturated between -1 and 1.

[0158] Many modifications can be made without departing from the scope of this presentation.

Claims

1. Demands Method for controlling a hybrid power plant (100), the method comprising at least once the implementation of the following steps: - considering a power setpoint (CP) of the power plant and a current instantaneous value (Ni) of the power plant control, the current instantaneous value (Ni) of the power plant control imposing a rate of change of a power value of the power plant, the setpoint (Cp) and the current instantaneous value (N0) aimed at compensating for a difference between a frequency of an electrical network and a nominal frequency of the network, determination (El) of a setpoint (Cft) for the activation of a reserve power (Pr') of an electrical production source (2) of the power plant (100) from a measured value (SOC) of a state of charge of an energy storage system (3) of the power plant and taking into account a minimum value and a maximum value that can be taken by a subsequent instantaneous value (Ni+i) of the power plant control, the reserve power of the source (Pr') being a predetermined power margin of the source,the minimum and maximum values ​​being a function of the current instantaneous control value (Ni) of the power plant and a predetermined threshold for the rate of change of the current instantaneous control value (Ni) of the power plant, the activation setpoint being between a first limit (Cpr- min ) and a second limit (0^ ^), the first and second limits being a function of a maximum power (Ps>max) available in the storage system, the reserve power (Pr) of the power plant, the reserve power (Pr') of the source, the current instantaneous control value (Ni) of the power plant, the minimum and maximum values ​​and a power variation rate threshold of the source; - Starting from the activation setpoint (CPr) of the source's reserve power and a reserve power of the power plant (Pr), determination (E2) of a current instantaneous value (N;') of the source control, the current instantaneous value (N;') of the source control imposing a rate of change of a source power value, the reserve power (Pr) being a power margin of the power plant predetermined; - from a setpoint (CP0) of power outside reserve of the source and the current instantaneous value (N;') of control of the source, determination (E3) of a power setpoint (CP') to be supplied by the source, the power outside reserve of the source corresponding to the power supplied by the power plant which does not contribute to the frequency control; - from a measurement of the power supplied by the source and the power setpoint (CP) of the power plant, determination (E4) of a power setpoint (CPS) to be supplied by the storage system (3) by compensating a difference between the power supplied by the source and the power setpoint (CP) of the power plant; and - control (E5) of a power (P') supplied by the source and a power (Ps) supplied by the storage system respectively from the power setpoint (CP') to be supplied by the source and the power setpoint (CPS) to be supplied by the storage system.

2. Method according to claim 1, implemented so that the first and second limits are determined respectively by the following expressions: C^ = / >,-(lW,)- / >;-^ Cpr 'jnax = " P*r + ( 1 + N; ) ' Pt+ Ps^max' with Cpr^njtl the first limit and Cpr'fljax the second limit, Pspiax the maximum power available in the storage system, Pr the reserve power of the plant, Pr' the reserve power of the source, and the current instantaneous value.

3. A method according to any one of claims 1 or 2, further comprising a (Eli) calculation of a second activation setpoint of the reserve power of the source for the subsequent instantaneous value, the method being implemented so that a slope value between a first point corresponding to the activation setpoint (CPr) calculated for the current instantaneous value and the activation setpoint calculated for the subsequent instantaneous value is bounded, for example by filtering, in order to respect the power rate threshold of the source.

4. A method according to any one of claims 1 to 3, implemented such that a minimum limit of the state of charge is a fraction, for example 40%, of a total storage system capacity and a maximum limit of the state of charge is equal to a fraction, for example 60%, of the total storage system capacity, and such that the activation setpoint (Cp / ) of the source reserve power is equal, if the measured value (SOC) of the state of charge is strictly greater than the maximum limit, to the first terminal (Cft ',min) and, if the measured value (SOC) of the state of charge is strictly less than the minimum limit, to the second terminal (Cp / ,^).

5. A method according to any one of claims 1 to 4, implemented so that the current instantaneous value (Ni) aims to deliver reserve power in less than 300 seconds, the current instantaneous value (Ni) being between -1 and 1.

6. A method according to any one of claims 1 to 4, implemented so that the current instantaneous value (Ni) aims to deliver the reserve power (Pr) of the power plant in less than 30 seconds to compensate for the difference between a frequency of an electrical network and a nominal network frequency, a value of the nominal network frequency being equal to 50.0 Hz and a value of the same difference being equal to -200 millihertz, the current instantaneous value (Ni) being proportional to the same difference.

7. A method according to any one of claims 1 to 6, further comprising a saturation step (E21) of the current instantaneous value (N;') of the source control.

8. Control device (1) of a hybrid power plant (100), the device being configured to implement a method according to any one of claims 1 to 7.

9. Product computer program comprising instructions which, when the program is executed by a computer, cause the computer to carry out a process according to any one of claims 1 to 7.

10. Computer-readable storage means on which a computer program product according to claim 9 is stored.

11. Hybrid power plant (100) comprising: - a control device (1) for the hybrid power plant according to claim 8; - a power generation source (2); and - an energy storage system (3), the generation source and the storage system being configured to be controlled by the control device.

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