Water turbine power generation system and control method for providing improved dynamic response to major power setpoint variations

Abstract

The invention relates to a method for controlling an energy production system (1), comprising: - a connecting link (6) provided with a connection (62) to an AC network (2); - a turbine system (3) comprising an electric machine (31) for delivering a nominal electrical power Pnom; - an energy storage system (14), comprising the following steps: - receipt of a first electrical power setpoint Ps0 and control of the turbine system (3) so as to deliver an electrical power Pt0 = Ps0; and - receipt of an electrical power setpoint Ps1, where ΔPs = Ps1 - Ps0 and |Δps| > Pnom*0.3; a) application of a hydraulic setpoint to the turbine system (3) so as to increase the delivered electrical power Pti thereof and prevent the storage system (14) from delivering electrical power (62); b) determination of the power Pea that the storage system (14) is able to supply; c) when Pti + Pea ≥ Ps1 - ε1, the storage system (14) delivers an electrical power Pe1 to satisfy the requirement Ps1 - ε1 ≤ Pe1 + Pti ≤ Ps1 + ε2.

Description

Hydraulic turbine power generation system and control method for providing an improved dynamic response following significant variations in the power setpoint

[0001] The invention relates to a monitoring strategy for optimizing the operation of a hybrid power generation system using a turbine system that generates electrical power for an alternating current (AC) grid as the primary energy source, and an energy storage system as the secondary source. The invention specifically addresses the management of significant variations in the electrical power setpoint. The invention also relates to the management of sudden changes in the electrical power setpoint.

[0002] Many power plants, particularly hydroelectric dams, include a turbine system to generate electrical power that is transferred to an AC grid via a connecting link. Significant variations in electrical power output can be requested by the AC grid operator from the power generation system. Due to its physical limitations, the turbine system cannot instantaneously provide a significant change in its electrical output. For example, the response time of a hydraulic system to a large change in the power setpoint is typically greater than 30 seconds, due in part to the inertia of the water column in the upstream penstocks connected to the turbine.

[0003] A hydraulic turbine system is configured to operate within a specific power output range. Outside this power output range, several undesirable phenomena can be expected. For example, with a Francis turbine, a system instability known as "S-shape" appears at power outputs between 0% and 20% of the rated output power; unstable vorticity appears between the turbine blades at power outputs between 20% and 40% of the rated output power; helical vorticity may appear downstream of the turbine at power outputs between 40% and 60% of the rated output power; and right-handed vorticity downstream of the turbine may appear at power outputs between 90% and 110% of the rated output power. These undesirable phenomena are known to cause damage. certain parts of the turbine system and prolonged use of the system under these conditions require operators to repair damaged parts, resulting in increased system interruptions for maintenance and, consequently, higher maintenance costs.

[0004] The hydraulic system can be combined with an energy storage system connected to the grid connection to increase the turbine system's responsiveness to a new electrical power setpoint transmitted by an AC grid operator. A control circuit receives an electrical power setpoint from the AC grid operator and, based on this setpoint, controls a transient power transfer between the grid connection and the energy storage system by selectively charging or discharging the energy storage system. When a new setpoint is received, the energy storage system contributes to this change by immediately participating in the power variation with the turbine.

[0005] However, given its cost, the energy storage system has limited capacity. Consequently, it can only contribute to a limited variation in electrical energy after a new electrical power setpoint has been transmitted by the AC grid operator. Thus, the actual electrical power supplied to the AC grid does not reach the setpoint requested by the AC grid operator quickly enough. Indeed, responsiveness to a change in the power setpoint has increasing market value in the context of integrating more renewable energy sources into electrical grids. This market value increases the profitability of the turbine system if this responsiveness can be improved.

[0006] It is therefore necessary to improve the responsiveness of an energy production system using a turbine system in order to respond to a new electrical power setpoint involving a significant power variation.

[0007] Furthermore, electricity suppliers can generate revenue from system manager requirements. These requirements are defined as requests to supply energy to a grid, requests that sometimes impose very short activation times, typically less than 1 second. Such power requests can be made to compensate for the difference between production and demand. Consumption across the electricity grid. Such services can generate significant revenue for electricity providers if these output power adjustment deadlines are met.

[0008] The hydraulic system can be combined with an energy storage system to increase the turbine system's responsiveness when a new electrical power demand is applied. A control circuit receives an electrical power demand transmitted by the AC grid operator or calculated from the frequency deviation observed at the electrical supply connection. Based on this demand, the circuit controls a transient power transfer between the supply connection and the energy storage system by selectively charging or discharging the energy storage system. When such a sudden new demand is received, the energy storage system contributes to this change by immediately matching the turbine's power output.

[0009] However, such a system currently relies on a large-capacity energy storage system, which increases its cost and size. To improve the adoption of energy production systems that include energy storage, it is important to keep their cost as low as possible.

[0010] The invention aims to resolve one or more of these drawbacks. The invention therefore relates to a method for controlling an energy production system, as defined in the attached claims.

[0011] The invention also relates to variants of the dependent claims. Those skilled in the art will understand that each of the features of the dependent claims or of the description can be combined independently with the features of an independent claim, but without constituting an intermediate generalization.

[0012] Other features and advantages of the invention will become clearer from the description given below, by way of example and without limitation, with reference to the accompanying drawings, in which:

[0013] [Fig. 1] is a schematic representation of an energy production system according to one embodiment of the invention;

[0014] [Fig.2] is a diagram illustrating the evolution of electrical power at different locations of an energy production system according to a first variant of the invention;

[0015] [Fig.3] is a diagram illustrating the evolution of electrical power at different locations of an energy production system according to a second variant of the invention;

[0016] [Fig.4] is a schematic representation of an energy production system according to another embodiment of the invention;

[0017] [Fig.5] is a schematic representation of an energy production system according to another embodiment of the invention;

[0018] [Fig.6] illustrates the electrical power supplied on the connection interface with power management according to the invention;

[0019] [Fig.7] illustrates the energy supplied by the energy storage device during the power management of figure 6;

[0020] [Fig.8] illustrates the electrical powers supplied on the connection interface according to a reference power management;

[0021] [Fig.9] illustrates the energy supplied by the energy storage device during the power management of figure 8.

[0022] Figure 1 is a schematic representation of a power generation system 1 according to a first embodiment of the invention. The power generation system 1 comprises a turbine system 3, an energy storage system 14, and a connecting link 6. The invention will be disclosed in the specific example of a hydraulic turbine system, but can also be applied to other turbine systems, such as gas turbines.

[0023] The turbine system 3 comprises an electric machine 31 (generally a synchronous machine) and a turbine 32 coupled to the electric machine 31. The turbine system 3 is essentially designed to provide electrical power to the connecting link 6. The turbine system 3 can also be reversible and designed to operate as a pump-turbine.

[0024] The connection link 6 includes a connection interface 62 for an AC network 2. The electric machine 31 and the energy storage system 14 are electrically connected to the connection link 6. The electric machine 31 is configured to generate electrical energy and transfer it to the AC network 2 via the connection interface 62.

[0025] The energy storage system 14 is configured to supply or absorb electrical power to / from the connection interface 62. In this embodiment of the invention, the energy storage system 1 comprises an AC / DC electrical transducer 12 and a DC converter 13. The AC interface of the AC / DC converter 12 is connected to the connection link 6, and the DC interface of the AC / DC converter 12 is connected to the DC electrical transducer 13, which enables power transfer between the connection link 6 and the DC transducer 13.

[0026] Connection interface 6 is connected to an AC network 2, typically a three-phase AC network. The AC network 2 can request electrical power by providing power setpoints corresponding to the power generation system 1.

[0027] The operation of the energy production system 1 is controlled by a control system. The control system in the illustrated example includes a main supervisor 7, a controller 8 for the electric machine 31, a controller 141 for the energy storage system, and a controller 9 for the turbine 32.

[0028] According to the invention, the energy production system 1 is controlled as follows. The following parameters will be used in the remainder of the description.

[0029] Pnom is the nominal electrical power of turbine system 3;

[0030] PsO is an initial setpoint for the electrical power received from the AC 2 network;

[0031] Ps1 is a subsequent electrical power setpoint received from the AC 2 network;

[0032] Aps = Ps1 - PsO corresponds to the variation in electrical power required by the CA 2 network;

[0033] PtO is the initial electrical power supplied by the turbine system 3 to the connection interface 62;

[0034] Pti is the instantaneous electrical power supplied by the turbine system 3;

[0035] Pea is the electrical power that the energy storage system can supply to the connection interface 62;

[0036] Peamax is the maximum electrical power exchanged at the connection interface 62 by the energy storage system 14, as permitted by the design of the energy storage system 14;

[0037] Pe1 is the instantaneous electrical power exchanged between the connection interface 62 and the energy storage system 14;

[0038] E1 and s2 are respectively the lower and upper power deviations tolerated by the CA 2 network;

[0039] The following steps are carried out. First, before a reference time t=0, the CA 2 network operates with an electrical power setpoint PsO sent by the supervisor 7 to the turbine system 3. At this stage, the power PsO delivered by the turbine system 3 to the connection interface 62 is equal to the electrical power setpoint PsO, say PtO = PsO.

[0040] At time t=0, the CA 2 network provides a subsequent power setpoint Ps1. The corresponding power setpoint Ps1 is, for example, received by the supervisor 7. The setpoint Ps1 implies a significant power variation; let's say it meets the following requirements: APs = Ps1 - PsO and |APs| > Pnom * 0.3.

[0041] The power variation implied by the setpoint Ps1 is either an increase in power (Ps1 > PsO) or a decrease in power (PsO > Ps1). In both cases, the power response Pti is not immediate.

[0042] For a power increase (PS1 > PSO):

[0043] a) A hydraulic setpoint is applied to the turbine system 3 to increase its output power Pti at the connection interface 62. The supervisor 7 can, for example, send a hydraulic power setpoint to the controller 9. The controller 9 can control the operation of the turbine 32 accordingly, for example, by adjusting the angle of the director's moving blades in a Francis turbine. The energy storage system 14 cannot simultaneously supply electrical power to the connection interface 62. Thus, the energy stored in the energy storage system 14 is conserved for later use;

[0044] b) the Poa power is determined. Poa is the maximum power that the energy storage system 14 can supply to the connection interface 62. The Poa power can in particular be supplied to the supervisor 7 by a state of charge controller of the energy storage system 14;

[0045] c) The following requirement is verified: Pti + Pea > Ps1 - d. The supervisor 7 can verify this requirement repeatedly. When this requirement is met, the energy storage system 14 is controlled to supply electrical power Pe1 to the connection interface in order to satisfy the requirement Ps1 - if < Pe1 + Pti < Ps1 + s2, with the power deviations e1 and E2 tolerated by the AC network 2.

[0046] The power Pe1 can initially be equal to Pea or at least equal to Pea / 2, or preferably at least equal to Pea*0.75. The power Pe1 can initially be greater than 0.05 * Pnom or even initially greater than 0.1 * Pnom.

[0047] For a decrease in power (PsO > Ps1):

[0048] n) A hydraulic setpoint is applied to the turbine system 3, in order to reduce its output power Pti at the connection interface 62. The supervisor 7 can, for example, send a hydraulic power setpoint to the controller 9. The energy storage system 14 cannot simultaneously recover electrical power from the connection interface 62. Thus, the storage capacity of the energy storage system 14 is preserved for later use;

[0049] o) The Poa power is determined. The Poa power is the maximum power that the energy storage system 14 can recover from the connection interface 62. The Poa power can in particular be supplied to the supervisor 7 by the controller 141 of the energy storage system 14;

[0050] (p) The following requirement is verified: Pti + Pea < Ps1 + E2. The supervisor 7 can verify this requirement repeatedly. When this requirement is met, the energy storage system 14 is controlled to recover electrical power Pe1 from the connection interface in order to satisfy the requirement Ps1 - £1 < Pe1 + Pti < Ps1 + E2.

[0051] According to the invention, the updated setpoint Ps1 can be reached more quickly without requiring increased energy capacity for the system. Energy storage 14. The invention overturns a common misconception among those skilled in the art: it teaches us to delay the power input to the energy storage system 14 in order to reach the new power setpoint more quickly. The invention is particularly effective if APs > Pnom*0.4, and even more so if APs > Pnom*0.5. The invention is especially advantageous if APs > 2*Peamax.

[0052] According to the invention, the control of the turbine 32 can be more aggressive since the use of the energy storage system 14 allows for a temporary overshoot of the electrical power generated by the electric machine 31 once the updated setpoint PS1 is reached. Indeed, a rapid convergence of Pti with Ps1 as the limit is less necessary; oscillations of the power Pti around the setpoint Ps1 are tolerated. The turbine 32 can therefore be controlled solely by taking into account its physical requirements. The turbine system 3 can thus provide a change in electrical power in less time.

[0053] In addition, controlling the turbine 32 to obtain an overshoot also allows the state of charge of the energy storage system 14 to be treated after its discharge, when the requirement Ps1 - £1 < Pe1 + Pti < Ps1 + E2 is satisfied.

[0054] Such control of the turbine 32 can be expressed in particular as follows. When the requirement Ps1 - e1 < Pe1 + Pti < Ps1 + E2 is satisfied, the turbine system 3 transiently supplies the electrical power Pti to the connection interface 62 with Pti > Ps1 if Ps1 > PsO, or Pti < Ps1 if PsO > Ps1. The electrical power Pti can transiently respond to the following relationships: Pti > Ps1 if Ps1 > PsO or Pti < Ps1 if PsO > Ps1.

[0055] A significant overrun may be accepted when the requirement Ps1 - £1 < Pe1 + Pti < Ps1 + c2 is satisfied, for example: if Ps1 > PsO, Pti > Ps1 + 0.1 * Pnom, or Pti > Ps1 + 0.15* Pnom, or even Pti > Ps1 + 0.2* Pnom; if PsO > Ps1, Pti < Ps1 - 0.1* Pnom, or Pti > Ps1 - 0.15* Pnom, or again Pti > Ps1 - 0.2* Pnom.

[0056] Once the requirement Ps1 - £1 < Pe1 + Pti < Ps1 + £2 is satisfied, the CA 2 network operator can be informed that the power setpoint Ps1 has been reached.

[0057] Power deviations £1 and £2 are set by the network operator CA 2, in order to define the tolerance for power deviations at the interface level. connection 62. These deviations can for example satisfy the requirements if < 0.02 * Pnom and e2 < 0.02 * Pnom, in preference to the control method according to claim 1, where E1 < 0.015 * Pnom and if possible where e2 < 0.015 * Pnom, and e1 < 0.01 * Pnom and e2 < 0.01 * Pnom.

[0058] To reduce the cost of the energy storage system 14, it can, for example, be designed so that Peamax < 0.2 * Pnom, or be designed so that Peamax < 0.15 * Pnom.

[0059] In some cases, the energy stored in the energy storage system 14 is either insufficient or not high enough to satisfy the requirement of the updated setpoint for a long period. For example, for a power increase Ps1 > Ps0, if the energy stored in the energy storage system 14 is less than Pea * (t2 - 11) / 2, the requirement Ps1 - £1 < Pti < Ps1 + £2 may not be met before time t2.

[0060] The supervisor 7 can integrate a digital clone of the turbine system 3 to forecast its electrical power output. Based on parameters such as the power Pti, the water flow rate, and the pressure inside the turbine or in its upstream conduits, the supervisor 7 can use the digital clone of the turbine system 3 and forecast the evolution of the instantaneous transient electrical power Ptm supplied by the electric machine 31 over a forecast horizon tp > t2 - t0. When it receives the setpoint Ps1, the supervisor 7 can forecast the instantaneous power Pem = Ps1 - Pti that will be supplied by the energy storage system 14 over the forecast horizon tp > t2 - t0.

[0061] By integrating the Pem signal for a period corresponding to the forecast horizon tp > t2 - t0, the supervisor 7 can calculate the power that will be demanded from the energy storage system 14 over the forecast horizon tp > t2 - t0. If the energy currently stored in the energy storage system 14 is less than the calculated energy, the energy storage system 14 will adjust its state of charge accordingly during the interval [t0 - 11].

[0062] If the energy storage system 14 does not have the capacity to store the calculated power, the power supply by the storage system Energy 14 can be deferred to allow the Pti to increase a little more, until the energy storage system 1 can supply the calculated power.

[0063] This can be applied in the same way for a decrease in the power setpoint.

[0064] In embodiments of the invention, the energy storage system 14 may include a storage device selected from the group consisting of a supercapacitor, a fuel cell, an electrochemical battery, an electric motor driving a flywheel, an air compressor and electromagnetic storage.

[0065] Figure 2 illustrates the operation of an energy production system 1 according to an embodiment of the invention. The solid line represents the total electrical power supplied to the connection interface 62. The dashed line represents the electrical power supplied by the electric machine 31 to the connection interface 62. The dashed line represents the electrical power exchanged by the energy storage system 14 with the connection interface 62. The upper limit corresponds to Ps1 + £2, and the lower limit corresponds to Ps1 - £2.

[0066] In this example, PtO = PsO = 0, let's say that the turbine system 3 does not supply power to the connection interface 62 before t = 0. At this point, the state of charge of the energy storage system 14 is sufficient for it to supply electrical power Poa to the connection interface 62, according to the invention. The energy storage system 14 can be fully or partially charged.

[0067] When t = 0, the AC network 2 sends the power setpoint Ps1 to the supervisor 7, with Ps1 = 0.8 * Pnom. Therefore, a significant increase in power is requested by the AC network 2. Until t = t1, the energy storage system 14 cannot supply electrical power to the connection interface 62. The energy storage system 14 cannot exchange electrical power with the connection interface 62 before t1. Thus, Pe1 = 0 between t = 0 and t1. Until t = t1, the turbine system 3 is controlled to increase the output electrical power Pti at the connection interface 62. Until t = t1, Pti + Pea < Ps1. Therefore, the power generation system 1 is unable to supply the electrical power corresponding to Ps1 before t1. Until that t = t1, the electrical power of the connection interface 62 is supplied solely by the turbine system 3.

[0068] When t = t1, the requirement Pti + Pea > Ps1 is met, and the state of charge of the energy storage system is sufficient to ensure continued operation. The energy storage system 14 is then controlled to supply the electrical power Pe1 with Ps1 - e1 < Pe1 + Pti < Ps1 + s2. Thanks to its power contribution, the energy storage system 14 allows the power setpoint Ps1 to be reached quickly.

[0069] The energy storage system 14 is used to meet this requirement, even after it has been met. As shown in Figure 2, aggressive control of the turbine 32 results in a power overshoot after t = t2: Pti > Ps1. Thus, after t2, the energy storage system 14 begins to recover electrical energy from the connection interface 42, in order to maintain Ps1 - e1 < Pe1 + Pti < Ps1 + e2. The previous discharge of the energy storage system 14 allows it to store more electrical power after such an overflow.

[0070] As illustrated in Figure 2, after t1, the electrical power Pti can oscillate around the setpoint Ps1. The energy storage system 14 compensates for these oscillations in order to maintain the power delivered to the connection interface 62 within the limits set by the network operator CA 2. Consequently, the energy storage system 14 sequentially recovers / distributes energy from / to the network CA 2.

[0071] Figure 3 illustrates the operation of an energy production system 1 according to another embodiment of the invention. The solid line represents the total electrical power supplied to the connection interface 62. The dashed line represents the electrical power supplied by the electric machine 31 to the connection interface 62. The dashed line represents the electrical power exchanged by the energy storage system 14 with the connection interface 62. The upper limit corresponds to Ps1 + s2, and the lower limit corresponds to Ps1 - s2.

[0072] In this example, PtO = PsO = 0, let's say that the turbine system 3 does not supply power to the connection interface 62 before t = 0. At this stage, the energy storage system 14 can be fully or partially charged.

[0073] When t = 0, the AC network 2 sends the power setpoint Ps1 to the supervisor 7, with Ps1 = 0.8 * Pnom. Consequently, a significant increase in power is requested by the AC network 2. Until t = t1, the energy storage system 14 recovers electrical power from the connection interface 62 in order to process its state of charge for subsequent operation.

[0074] Until t = t1, the turbine system 3 is controlled to increase the electrical output power Pti at the connection interface 62. Until t = t1, Pti + Pea < Ps1. Therefore, the power generation system 1 is not able to supply the electrical power corresponding to Ps1 before t1.

[0075] Until t = t3, the electrical power supplied by the turbine system 3 to the connection interface 62 is recovered by the energy storage system 14. Therefore, until t3, no electrical power is supplied to the connection interface 62; all the available electrical power Pti is transferred to the energy storage system 14. This does not cause any problems for the management of the AC 2 network, since the available power is not sufficient to reach the setpoint Ps1.

[0076] When t = t3, the energy stored in the energy storage system 14 has reached a sufficient value for continued operation. Between t3 and t1, there is no power exchange between the energy storage system 14 and the connection interface 62. The electrical power supplied to the connection interface 62 therefore corresponds to the electrical power supplied by the turbine system 3 to this interface 62.

[0077] When t = t1, the requirement Pti + Pea > Ps1 - e1 is satisfied. The energy storage system 14 is then controlled to supply the electrical power Pe1 with Ps1 - e1 < Pe1 + Pti < Ps1 + e2. Thanks to its power contribution, the energy storage system 14 allows the power setpoint Ps1 to be reached quickly. The behavior of the electricity generation system 1 is then identical to the behavior disclosed for the embodiment in Figure 2.

[0078] The following control parameters can be used. Supervisor 7 can receive active / reactive power setpoints from the AC network 2. Supervisor 7 will set the respective power inputs to the energy storage system 14 and the hydraulic system 3, providing them with corresponding setpoints. Supervisor 7 can send the respective setpoints to controllers 141, 8 and 9. Supervisor 7 can also transmit additional information, for example the AC network voltage value 2, to controllers 141 and 8.

[0079] The controller 9 can receive the instantaneous power value Pti supplied by the electric machine 31 at the connection interface 62, in order to correct the control of the hydraulic turbine 32.

[0080] The AC / DC converter 12 is configured to be current reversible. The AC / DC converter 12 is controlled by the controller 141.

[0081] Figure 4 is a schematic representation of an energy production system 1 according to a second embodiment of the invention. This embodiment is identical to the second, except for the structure of its energy storage device 14. In this embodiment, the DC electrical transducer 13 of the energy storage system 14 comprises a DC / DC converter 131 and an electrical energy storage device 132. The DC / DC converter 131 electrically connects the energy storage system 14 to the DC interface of the AC / DC converter 12. The DC / DC converter 131 is configured to adapt the voltage level between the storage device 132 and the DC interface of the AC / DC converter 12. The operation of the electrical transducer 13 can be controlled by a control circuit 133.

[0082] Figure 5 is a schematic representation of a power generation system 1 according to another embodiment of the invention, in an aspect independent of this invention. The power generation system 1 comprises a turbine system 3, an energy storage system 14, and a connecting link 6. The invention will be disclosed in the specific example of a hydraulic turbine system, but can also be applied to other turbine systems, such as gas turbines.

[0083] The turbine system 3 comprises an electric machine 31 (generally a synchronous machine) and a turbine 32 coupled to the electric machine 31. The turbine system 3 is essentially designed to provide electrical power to the connecting link 6. The turbine system 3 can also be reversible and designed to operate as a pump-turbine.

[0084] The connection link 6 includes a connection interface 62 for an AC network 2. The electric machine 31 and the energy storage system 14 are electrically connected to the connection link 6. The electric machine 31 is configured to generate electrical energy and transfer it to the AC network 2 via the connection interface 62.

[0085] The energy storage system 14 is configured to supply or absorb electrical power to / from the connection interface 62. In this embodiment of the invention, the energy storage system 14 comprises an AC / DC electrical transducer 12 and a DC converter 13. The AC interface of the AC / DC converter 12 is connected to the connection link 6, and the DC interface of the AC / DC converter 12 is connected to the DC electrical transducer 13, which enables power transfer between the connection link 6 and the DC transducer 13.

[0086] Connection interface 6 is connected to an AC network 2, typically a three-phase AC network. The AC network 2 can request electrical power by providing power setpoints corresponding to the power generation system 1.

[0087] The operation of the energy production system 1 is controlled by a control system. The control system in the illustrated example includes a main supervisor 7, a controller 8 for the electric machine 31, a controller 141 for the energy storage system, and a controller 9 for the turbine 32.

[0088] According to this embodiment of the invention, the energy production system 1 is controlled as follows.

[0089] The controller 9 is configured to apply a fluid parameter setpoint to the turbine 32, this parameter influencing the electrical power supplied by the electric machine 31. More specifically, for a hydraulic turbine 32, the fluid parameter setpoint can be a setpoint for the opening of the turbine's control valve 32. The electric machine 31 thus supplies instantaneous electrical power Ph to the connection link 6.

[0090] Controller 7 receives a setpoint P* from the AC network 2 to be delivered on the connection interface 62 (the setpoint P* can also be calculated locally by controller 7, for example by taking into account frequency variations). Before time t=0, the value of the setpoint P* is PsO. The turbine system 3 is therefore ordered to deliver a power PhO = PsO on the connection interface 62. The energy storage system 14 is therefore not used, or can be charged or used transiently.

[0091] At time t = 0, the value of the setpoint P* is Ps1. APs = Ps1 - PsO, with Ps1 > PsO. Thus, at time t = 0, a sudden increase in the value of the setpoint P* is required.

[0092] Based on a predictive control model of the electrical power generated by turbine system 3, successive operating parameters of the turbine controller 9 are determined so that the power Ph reaches the value Ps1 with a minimum amount of additional energy to be supplied by the energy storage system 1. Thus, controller 7 successively sends hydraulic power commands Ph* to the turbine controller 9 until the system reaches equilibrium. Controller 7 also sends successive power commands Pb* to the energy storage system 14 until the system reaches equilibrium. The power commands are defined to follow the relationship Ph* + Pb* = Ps1.

[0093] Model predictive controllers (MPCs) rely on dynamic models of a process, most often linear empirical models obtained by identifying a system. The models used in MPCs are generally designed to represent the behavior of complex dynamic systems. MPCs are based on finite-horizon iterative optimization subject to the constraints of a system model. At time t, the current state of the system is sampled, and a cost-minimizing control strategy is calculated (using a numerical minimization algorithm) for a relatively short time horizon in the future: [t, t + T], where t is the current time and T is the prediction time or prediction horizon.More precisely, an online or on-the-fly computation is used to explore state trajectories emanating from the current state and to find (via the solution of the Euler-Lagrange equations, for example) a control strategy that minimizes costs up to time t + T. Only the first step of the control strategy is implemented at time [t, t+Ts], where Ts is the controller sampling time. Then, the system state is sampled again, and the computations are repeated from the new current state, yielding a new control and a new predicted state path. The horizon. prediction continues to be shifted towards the future and for this reason, predictive model controllers are also called receding horizon controllers.

[0094] Until the hydraulic system stabilizes at the target output power (Ph reaches Ps1), the energy storage system 14 applies real electrical power Pb to the connecting link 6, with Pb + Ph = Ps1. Simultaneously, the successive operating parameters provided by the turbine controller 9 are applied to the turbine 32.

[0095] Typically, the successive operating parameters determined by the controller 7 are power setpoints for the turbine 32. These setpoints are determined by predictive model control, minimizing a cost function defined as the amount of additional energy to be supplied to the turbine during the prediction horizon to meet the high-level requirements associated with the new power setpoint. As a secondary objective, the same process is used to ensure load-state control of the energy storage system 14.The calculation of the best set of operating parameters of the turbine controller 9 also includes the following constraints: i) the additional energy to be supplied must not be greater than what the energy storage system 14 can absorb (or supply) according to its actual state of charge, ii) the planned additional power must not be greater than what the energy storage system 14 can absorb (or supply) according to its actual state of health, iii) the stability margins of the turbine system 3 and its controller 9 must be respected.

[0096] Figure 6 illustrates the corresponding powers applied to the connection interface 62 according to the invention. Figure 6 shows the overall electrical power supplied to the connection interface 62 in dashed lines. The hydraulic power Ph supplied to the connection interface 62 is shown in solid lines. Figure 7 illustrates the amount of energy to be delivered by the energy storage device 14 during the same period (corresponding to the area between the solid and dashed lines in Figure 6). As can be seen, the energy supplied by the energy storage device 14 until Ph reaches Ps1 is, for example, approximately 1 kWh.

[0097] Figure 8 illustrates the total electrical power supplied to the connection interface 62 (shown in dashed lines) for a reference power management system. According to this prior art power management system, the turbine 32 is controlled to to provide a hydraulic power Ph that remains below Ps1. The hydraulic power Ph supplied at connection interface 62 is shown in solid lines. Figure 9 illustrates the amount of energy to be delivered by the energy storage device 14 during the same energy management period. As can be seen, the energy supplied by the energy storage device 14 until Ph reaches Ps1 is approximately 1.5 kWh.

[0098] Therefore, according to the invention, the energy required by the energy storage device 14 is reduced. Thus, an energy storage device 14 with a reduced capacity (and therefore lower cost and size) can be used.

[0099] To ensure that the energy storage device 14 is able to supply the required energy to the connection link 6, the controller 7 also determines the amount of additional energy Emin that the energy storage system 14 must supply to the connection link 6 to meet the requirement Ps1 = Pb + Ph up to Ph = Ps1. The electrical power satisfying the requirement Pb + Ph = Ps1 and the application of the successive determined operating parameters of the turbine 32 are only triggered when the instantaneous available energy of the energy storage system 14 satisfies Eess > Emin.

[0100] Depending on the requirements set by the network managers, the electrical power meeting the requirement Pb+Ph= PS1 and the application of the successive determined operating parameters of the turbine 32 are triggered less than 5s after receiving the electrical power setpoint Ps1, preferably less than 2s, preferably less than 1s, preferably less than 500ms, and preferably less than 300ms.

[0101] According to another variant of this embodiment of the invention, the power generation system 1 is controlled as follows. In this embodiment, the turbine controller 9 is a PID controller, having at least one variable gain (either one or more of a proportional gain, an integration gain and a derivation gain).

[0102] As with the previous variant, the turbine controller 9 is configured to apply a fluid parameter setpoint to the turbine 32 influencing the electrical power delivered by the electric machine 31. The electric machine 31 thus delivers an instantaneous electrical power Ph to the connection link 6.

[0103] Controller 7 receives a setpoint P* from the AC network 2 to be delivered to connection interface 62. Before time t=0, the value of the setpoint P* is PsO. The turbine system 3 is therefore controlled to deliver a power PhO = PsO to connection interface 62. The energy storage system 14 is therefore not used, or can be charged or used transiently.

[0104] At time t = 0, the value of the setpoint P* is Ps1. APs = Ps1 - PsO, with Ps1 > PsO. Thus, at time t = 0, a sudden increase in the value of the setpoint P* is required.

[0105] Based on a predictive model control of the electrical power generated by turbine system 3, successive values ​​of a variable turbine controller gain 9 are determined so that the power Ph reaches the value Ps1 with a minimum amount of additional energy supplied by the energy storage system 14. Successive values ​​can be determined for several different gains of the turbine controller 9.

Claims

DEMANDS Claim 1. [Method for controlling an electricity production system (1) comprising: -a connection link (6) comprising a connection interface (62) for connection to a CA network (2); - a turbine system (3) comprising an electric machine (31) and configured to deliver a nominal electrical power Pnom to the connection link (6); - an energy storage system (14) connected to the connection link (6); the control method comprising the following steps: - the reception from the AC network (2) of a first electrical power command PsO to be delivered to the connection interface (62) and the control of the turbine system (3) in order to deliver an electrical power PtO = PsO to the connection interface; and - the reception of another electrical power setpoint Ps1 from the AC network (2) with APs = Ps1 - PsO and |APs| > Pnom * 0.3; If Ps1 > PsO: a) applying a hydraulic setpoint to the turbine system (3) to increase its electrical output Pti and prevent the energy storage system (14) from supplying electrical power to the connection interface (62); b) determining the power Pea that the energy storage system (14) can supply to the connection interface; c) when Pti + Pea > Ps1 - if , controlling the energy storage system (14) to supply electrical power Pe1 to the connection interface to satisfy the requirement Ps1 - e1 < Pe1 +Pti < Ps1 + s2, with the power deviations e1 and s2 tolerated by the AC network (2) at the connection interface (62); or If PsO > Ps1: n) the application of a hydraulic setpoint to the turbine system in order to reduce its delivered electrical power Pti and to prevent the energy storage system (14) from recovering electrical power from the connection interface; o) the determination of the power Pea that the energy storage system (14) can recover from the connection interface (62); p) when Pti + Pea < Ps1 + E2, the control of the energy storage system (14) to recover electrical power Pe1 from the connection interface in order to satisfy the requirement Ps1 - e1< Pe1 + Pti < Ps1 + e2. Claim 2. Control method according to claim 1, wherein £1 < 0.02 * Pnom and E2 < 0.02 * Pnom. Claim 3. Control method according to claim 1 or 2, wherein an achievement signal is sent to a network management system AC (2) when the requirement Ps1 - e1 < Pe1 + Pti < Ps1 + £2 is satisfied. Claim 4. A control method according to any one of the preceding claims, wherein a hydraulic setpoint is applied to the turbine system so that it transiently supplies electrical power Pti to the connection interface when the requirement Ps1 - E1 < Pe1 + Pti < Ps1 + £2 is satisfied, with: Pti > Ps1 if Ps1 > PsO; or Pti < Ps1 if PsO > Ps1. Claim 5. Control method according to claim 4, wherein, when the requirement Ps1 - £1 < Pe1 + Pti < Ps1 + £2 is satisfied, the electrical power Pti responds transiently to the relation: Pti > Ps1 +0.1 * Pnom if Ps1 > PsO; or Pti < Ps1 - 0.1 * Pnom if PsO > Ps1. Claim 6. A control method according to claim 4 or 5, wherein the energy storage system (14) is controlled to sequentially absorb and supply electrical power to the connection interface when the requirement Ps1 - £1 < Pe1 + Pti < Ps1 + £2 is satisfied. Claim 7. A control method according to any one of the preceding claims, wherein Pe1 = 0 between the time of receipt of the setpoint Ps1 and the time when Pti + Pea - £1 > Ps1 or between the time of receipt of the setpoint Ps1 and the time when Pti + Pea + £2 < Ps1. Claim 8. A control method according to any one of claims 1 to 6, wherein, between the time of receipt of the setpoint Ps1 and the time when Pti + Pea - s1 > Ps1: Pel < 0 if Ps1 > PsO; or Pel > 0 if PsO > Ps1. Claim 9. Energy production system (1) characterized in that it comprises: - a connection link (6) comprising a connection interface (62) for connection to a CA network (2); - a turbine system (3) comprising an electric machine (31) and configured to deliver a nominal electrical power Pnom to the connection link (6); - an energy storage system (14) connected to the connection link (6); - a control system (7) configured to control the operation of the energy production system (1), the control system (7) being configured to: - the reception from the AC network (2) of a first electrical power setpoint PsO to be delivered to the connection interface (62) and the control of the turbine system (3) in order to deliver an electrical power PtO = PsO to the connection interface; and - the reception of another electrical power setpoint Ps1 from the AC network (2), with APs = Ps1 - PsO and |APs| > Pnom * 0.3; If Ps1 > PsO: a) applying a hydraulic setpoint to the turbine system (3) to increase its electrical output Pti and prevent the energy storage system (14) from supplying electrical power to the connection interface (62); b) determining the power Pea that the energy storage system (14) can supply to the connection interface; c) when Pti + Pea > Ps1-s1, controlling the energy storage system (14) to deliver electrical power Pe1 to the connection interface to satisfy the requirement Ps1 - E1 < Pe1 + Pti < Ps1 + £2, with the power deviations E1 and E2 tolerated by the AC network (2) at the connection interface (62); or If PsO > Ps1: n) the application of a hydraulic setpoint to the turbine system in order to reduce its electrical power output Pti and prevent the storage system 22 of energy (14) to recover electrical power from the connection interface; o) the determination of the power Pea that the energy storage system (1) can recover from the connection interface (62); p) when Pti + Pea < Ps1 + E2, the control of the energy storage system (14) to recover electrical power Pe1 from the connection interface in order to satisfy the requirement Ps1 - e1< Pe1 + Pti < Ps1 + e2. Claim 10. Energy production system (1) according to claim 9, wherein the energy storage system (14) comprises a DC electric transducer (13), an AC / DC converter (12) having an AC interface connected to the connecting link (6) and a DC interface connected to the DC electric transducer (13). Claim 11. Energy production system (1) according to claim 10, wherein the energy storage system (14) comprises a DC / DC converter (131) configured to change the voltage level between the DC electrical transducer (132) and the AC / DC converter (12). Claim 12. Power generation system (1) according to claim 11, wherein the DC electric transducer (13) is selected from the group comprising a supercapacitor, a fuel cell, an electrochemical battery, an electric motor driving a flywheel, an air compressor and electromagnetic storage. Claim 13. Energy production system (1) according to any one of claims 9 to 12, wherein Pe1 > Pea / 2. Claim 14. A method for controlling an electricity generation system (1) comprising: -a connection link (6) comprising a connection interface (62) for connection to a CA network (2); - a turbine system (3) comprising an electric machine (31), a turbine (32) and a turbine controller (9), the turbine controller being configured to deliver at least one fluid parameter setpoint to the turbine (32) influencing the electrical power delivered by the electric machine (31), the electric machine (31) delivering instantaneous electrical power Ph to the connection link (6); - an energy storage system (14) connected to the connection link (6); 23. The control procedure comprising the following steps: -a) receive a first electrical power command PsO to be delivered to the connection interface (62) and control the turbine system (3) in order to deliver an electrical power PhO = PsO on the connection interface; and - b) receive a subsequent electrical power setpoint Ps1 (2) , with APs = Ps1 - PsO, with Ps1 > PsO ; c) based on a predictive model control of the electrical power generated by the turbine system (3), determine successive operating parameters of the turbine controller (9a so that Ph reaches Ps1 with a minimum amount of additional energy; -d) Until Ph=Ps1, apply an electrical power Pb on the connecting link (6) by means of the energy storage system (14), with Pb+Ph=Ps1, and apply the successive operating parameters to the turbine controller (9). Claim 15. A method for controlling an electricity production system (1) according to claim 14, wherein an energy storage system (14) has an instantaneous available energy Eess, the method further comprising determining the additional energy Emin that the electrical energy system (14) must supply to the connecting link (6) to fulfill the condition Ps1 = Pb + Ph until Ph = Ps1, wherein step d) is triggered only when Eess > Emin. Claim 16. Method of controlling an electricity production system (1) according to claim 14 or 15, wherein step d) is triggered less than 5 seconds after step b). Claim 17. Method of controlling an electricity production system (1) according to claim 16, wherein step d) is triggered less than 1 second after step b). Claim 18. A method for controlling an electricity generation system (1) according to any one of claims 14 to 17, wherein the successive operating parameters are the operating points of the turbine, wherein step c) is carried out by iteratively evaluating the instantaneous power Ph, comparing the evaluated instantaneous power Ph to the electrical power anticipated by the predictive model control, and determining parameters of 24 successive operations updated for the turbine controller (9) so that Ph reaches Ps1 with a minimum amount of additional energy. Claim 19. Method of controlling an electricity production system (1) according to any one of claims 14 to 17, wherein the turbine controller (9) is a PID controller, the successive operating parameters being successive values ​​of at least one gain variable selected from a proportional gain, an integration gain and a derivation gain. Claim 20. Method of controlling an electricity production system (1) according to any one of claims 14 to 19, wherein said turbine (32) is a hydraulic turbine, and wherein said fluid parameter setpoint is a guide valve opening setpoint of the hydraulic turbine (32). Claim 21. A method for controlling an electricity generation system (1) according to any one of claims 14 to 20, wherein the first received electrical power setpoint PsO is received from the AC network (2). Claim 22. A method for controlling an electricity generation system (1) according to any one of claims 14 to 20, wherein the first received electrical power setpoint PsO is calculated by the power generation system (1).

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