Power generation system with hydro turbine having improved dynamic response - Patents.com

Abstract

The present invention relates to a power generation system (1), comprising: a hydro-turbine system (3) having an undesirable power output setpoint and a specific safe power output setpoint; an energy storage system (14); a feeder link (6) connected to the energy storage system (14), an electric machine of the hydro-turbine system (3), and the feeder link (6) connected to an AC power network (2); a device for determining a state of charge (19); and a control circuit (18) for controlling the transmission of power between the feeder link (6) and the energy storage system (14), the control circuit (18) being configured to receive a power setpoint Reps and to determine that the received power setpoint Reps belongs to the undesirable power output setpoint, and to generate a power transmission setpoint Epts and an actual power output setpoint Aepos that satisfy the relationship Reps=Epts+Aepos and belong to the safe power output setpoint.

Description

[Technical Field]

[0001] The present invention relates to power generation systems using hydro-turbine systems to generate electrical power for an AC grid, and more particularly to extending the operating range of the power generation system and mitigating unintended phenomena during operation of the hydro-turbine system. Summary of the Invention [Problem to be solved by the invention]

[0002] Many hydroelectric dams include a hydroelectric turbine system for generating electrical power that is sent to an AC grid via a feeder link. Such systems may include an energy storage system connected to the connecting link to increase the responsiveness of the turbine system to new power setpoints provided by a grid operator. Such an energy storage system is particularly useful when the new power setpoints involve large power fluctuations. A control circuit receives the power setpoint transmitted from the grid operator and, based on the setpoint, controls the temporary transmission of power between the feeder link and the energy storage system by selectively controlling the charging or discharging of the energy storage system. The turbine system is configured to operate within a specific output power range. Outside this output power range, certain undesirable phenomena can be expected. For example, in the case of a Francis turbine, a system instability known as an "S-shape" appears between 0% and 20% of nominal power output, unstable vortices appear between the turbine blades between 20% and 40% of nominal power output, spiral cables appear downstream of the turbine between 40% and 60% of nominal power output, and axial cables appear downstream of the turbine between 90% and 110% of nominal power output. These undesirable phenomena are known to damage turbine system components, and prolonged use of the system under these conditions requires operators to repair damaged components, resulting in increased system downtime for maintenance and increased maintenance costs.

[0003] Therefore, there is a need to extend the output power range while suppressing the various undesirable phenomena mentioned above.

[0004] EP3579369 describes a method for using hydroelectric power as a power reserve for a power grid. Several hydroelectric generators, each with a separate output power level, are used to supply the grid with all of its power output. The AC frequency of the grid is monitored to detect deviations from a reference frequency range. If deviations from this frequency range are detected, power is transferred between a storage device and the grid.

[0005] Document DE102011119384 describes a hydroelectric power plant with a turbine mechanically connected to a generator. At least one inertial energy storage device is connected to the generator. The inertial energy storage device comprises an electric machine, and the generator and the electric machine are connected. [Means for solving the problem]

[0006] The present invention aims to solve one or more of these problems. Accordingly, the present invention relates to a power generation system as defined in claim 1 attached hereto.

[0007] The invention also relates to variants of the dependent claims. A person skilled in the art will understand that each feature of the description or the dependent claims can be independently combined with the features of the independent claims without intermediate generalizations. [Brief explanation of the drawings]

[0008] Further characteristics and advantages of the present invention will become more apparent from the following description, given by way of example and not of limitation, with reference to the accompanying drawings, in which: [Figure 1] FIG. 1 is a schematic diagram of a power generation system according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of a power generation system according to a second embodiment of the present invention. [Figure 3] FIG. 3 is a schematic diagram of a power generation system according to a third embodiment of the present invention. [Figure 4] FIG. 4 is a schematic diagram of a power generation system according to a fourth embodiment of the present invention. [Figure 5] FIG. 5 shows the range of power settings for a water turbine system as a function of the water level. [Figure 6] FIG. 6 is a power output setpoint range diagram illustrating an example of setpoint offsetting to prevent a water turbine from operating in an unsafe and undesirable power setpoint range. [Figure 7] FIG. 7 is a power output setpoint range diagram illustrating another example of setpoint offsetting to prevent a water turbine from operating in an unsafe and undesirable power setpoint range. [Figure 8] FIG. 8 is a diagram showing changes over time in a plurality of different output power setting values ​​in response to changes in the state of charge. [Figure 9] FIG. 9 is a diagram of a power setpoint range modified according to water level, with an expanded upper and lower power setpoint range. [Figure 10] FIG. 10 is a diagram of a modified electrical output setpoint range depending on water level, illustrating an example of a power transfer setpoint offset that prevents the water turbine system from operating in an undesirably low, risky electrical output setpoint range. [Figure 11] FIG. 11 is a diagram of the range of power setpoints (Rep) as a function of water level, with the extended upper and lower power setpoint ranges within the upper power setpoint range. [Figure 12] FIG. 12 is a diagram illustrating the range of power setpoints for the water turbine system of FIG. 2 as a function of water level. [Figure 13] FIG. 13 is a diagram of power output setpoint ranges, illustrating an example of offsetting the setpoint to prevent operation of the water turbine system of FIG. 2 in unachievable and undesirable power setpoint ranges. [Figure 14]FIG. 14 is a diagram of power output setpoint ranges, illustrating an example of offsetting the setpoint to prevent operation of the water turbine system of FIG. 2 in unachievable and undesirable power setpoint ranges. [Figure 15] FIG. 15 illustrates a number of different power set points over time in response to changes in the state of charge of the water turbine system of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] 1 is a schematic diagram of a power generation system 1 according to a first embodiment of the present invention. The power generation system 1 includes a hydro-turbine system 3 with an electric machine 31 (typically a synchronous machine), an energy storage system 14, a state-of-charge determination device 19, a control circuit 18, a connection interface 62, and a feeder link 6. The feeder link 6 connects the electric machine 31 to the connection interface 62. The energy storage system 14 is connected to the feeder link 6. The control circuit 18 is connected to the state-of-charge determination device 19, the energy storage system 14, and the hydro-turbine system 3. The state-of-charge determination device 19 is configured to determine the state of charge of the energy storage system 14.

[0010] The connection interface 6 is connected to an AC grid 2, typically a three-phase AC grid. Furthermore, a control circuit 22 is connected to the AC grid 2 and is used to generate a power setpoint Reps based on the power required by the AC grid 2. The electric machine 31 is configured to generate power and send the power to the AC grid 2 via the connection interface 62.

[0011] FIG. 5 illustrates a range of power setpoints for the hydro-turbine system 3 according to the water level H. The vertical axis represents the power P0 of the hydro-turbine system 3, and the horizontal axis represents the water level H. The power setpoint range includes undesirable power output setpoints with specific risks, indicated by an area 93. The undesirable power output setpoints with specific risks may correspond to S-shaped instability of a Francis turbine or a reversible Francis turbine, the occurrence of unstable vortices between multiple turbine blades, the appearance of a spiral cable downstream of the turbine, or the appearance of an axial cable downstream of the turbine. A blank area 90 indicates a range of safe power setpoints. The blank area 90 includes a lower safe output power area 922 and an upper safe output power area 921. The area outside the blank area 90 can be considered an unreachable area.

[0012] The control circuit 18 is configured to receive a power setpoint Reps from the control circuit 22 (e.g., via the communication link 23). Here, the control circuit 18 is configured to receive a current water level value H from the hydro-turbine system 3. The control circuit 18 then determines whether the power setpoint Reps provided by the control circuit 22 belongs to a particular risky undesirable output power setpoint, as shown in region 93 in Fig. 5. The control circuit 18 may also receive any related parameters to determine whether the power setpoint Reps belongs to region 93.

[0013] The control circuit 18 generates an actual power setpoint Aepos and a power transfer setpoint Epts depending on the power setpoint Reps and the state of charge of the energy storage system 14 . This actual power setpoint Aepos is selected as one of the specific safe power output setpoints and corresponds to region 90 in Figure 5. This setpoint Aepos is then supplied to the turbine system 3. This power transfer setpoint Epts is then provided to the energy storage system 14. This setpoint Epts is set according to the determined state of charge of the energy storage system 14. The setpoint Epts causes the energy storage system 14 to be charged or discharged and power to be transmitted using the feeder link 6.

[0014] The set values ​​Epts and Aepos are determined by the control circuit 18 so as to satisfy the relationship Reps=Epts+Aepo.

[0015] When the respective setpoints Epts and Aepos are provided, the energy storage system 14 and the hydro-turbine system 3 provide the corresponding power via the connection link 6. This allows the power generation system 1 to provide the required power Reps to the AC grid 2 without causing the hydro-turbine system 3 to operate in an undesirable and dangerous manner. Different aspects of the management of the state of charge of the energy storage system 14 are highlighted below.

[0016] 6 shows a first operating mode of the power generation system 1. A setpoint value Reps is received by the control circuit 18 and is indicated in the undesired risk area 93. In this first operating mode of the power generation system 1, the energy storage system 14 is determined to be discharged rather depending on its state of charge. The state of charge determines whether the energy storage system 14 is discharging or charging. mosquito To determine this, the control circuit 18 compares the energy storage system 14 with a threshold level (e.g., 50%). and Then, the set value Aepos is set higher than the set value Reps of the area 921. This set value Aepos is sent to the hydro-turbine system 3. The set value Epts is set to charge the energy storage system 14, and the hydro-turbine system 3 sends the charging power to the energy storage system 14. This set value Epts is provided to the energy storage system 14.

[0017] 7 shows a first operating mode of the power generation system 1. The setpoint value Reps is received by the control circuit 18 and is also indicated in the risk area 93. In this first operating mode of the power generation system 1, the energy storage system 14 is, depending on its state of charge, rather Mitsuru electric andNext, the setpoint Aepos is set to be lower than the setpoint Reps of the region 922. This setpoint Aepos is sent to the hydro-turbine system 3. The setpoint Epts is set to discharge the energy storage system 14, and the energy storage system 14 sends power to the AC grid 2. This setpoint Epts is provided to the energy storage system 14.

[0018] As shown in Figure 8, the control circuit 18 can alternate between a first operating mode and a second operating mode. Figure 8 shows the change in the setpoint over time. In this example, the setpoint Reps (dotted line) received by the control circuit 18 remains at the same level in the undesirable risk region 93. The setpoint Aepos is shown as a solid line. The setpoint Epts is shown as a dotted line. In the first stage, the energy storage system 14 is charged. As a result, the setpoint Epts becomes negative, the setpoint Aepos is greater than the setpoint Reps, and the energy storage system 14 is charged.

[0019] When a predetermined charge level of the energy storage system 14 is reached, the energy storage system 14 must be discharged. As a result, the setpoints Epts and Aepos are gradually offset. Thus, the setpoint Epts is set to be positive and the setpoint Aepos is lower than the setpoint Reps.

[0020] When a predetermined discharge level of the energy storage system 14 is reached, the energy storage system 14 must be charged. As a result, the setpoints Epts and Aepos are gradually offset, so that the setpoint Epts is negative and the setpoint Aepos is higher than the setpoint Reps.

[0021] 9 illustrates a range of power settings for the power generation system 1 modified according to the water level of its hydro-turbine system 3. The power setpoint range includes an extended upper power setpoint range and a lower power setpoint range, which extend into an upper region 931 and a lower region 932, which are regions that cannot be reached or are prohibited by the turbine system 3.

[0022] 10 shows a first operating mode of the power generation system 1. The setpoint Reps is received by the control circuit 18 and is shown in the undesirable lower risk region 932. In this first operating mode of the power generation system 1, it is determined that the energy storage system 14 should be discharged according to its state of charge. Then, the setpoint Aepos is set higher than the setpoint Reps in the region 90. This setpoint Aepos is sent to the hydro-turbine system 3. The setpoint Epts is set so that the energy storage system 14 is charged, and the hydro-turbine system 3 sends charging power to the energy storage system 14. This setpoint Epts is provided to the energy storage system 14. This allows the power generation system 1 to quickly provide power less than the power that the hydro-turbine system 3 can provide alone.

[0023] To enable such charging of the energy storage system 14, the control circuit 18 may proactively pre-discharge the energy storage system 14. For example, if the control circuit 18 identifies a setpoint Epts that approaches the undesirable lower risk region 932, it discharges the energy storage system 14, thereby enabling subsequent charging of the energy storage system 14. To achieve discharging, Epts can be set positive and Aepos can be made small, so that the output power of the power generation system 1 is equal to Reps.

[0024] FIG. 11 illustrates a fourth operating mode of the power generation system 1. The setpoint Reps is received by the control circuit 18 and is shown in the undesired upper risk region 931. In this fourth operating mode of the power generation system 1, it is determined that the energy storage system 14 should be discharged according to its state of charge. A setpoint Aepos is then set lower than the setpoint Reps in region 90. This setpoint Aepos is sent to the turbine system 3. A setpoint Epts is set so that the energy storage system 14 is discharged, and the energy storage system 14 sends power to the AC grid 2. This setpoint Epts is provided to the energy storage system 14. This allows the power generation system 1 to quickly supply less power than the hydro-turbine system 3 alone can supply.

[0025] To enable such discharge of the energy storage system 14, the control circuit 18 may preload the energy storage system 14. For example, if the control circuit 18 identifies a setpoint Epts that approaches the undesirable upper risk region 931, it may charge the energy storage system 14, thereby enabling subsequent discharge of the energy storage system 14. To achieve discharge, Epts may be set positive and Aepos may be reduced, so that the output power of the power generation system 1 is equal to Reps.

[0026] The state-of-charge determination device 19 may include a sensor that measures the voltage or current of the energy storage system 14, or a computer that simulates the instantaneous state of charge of the energy storage system 14 according to its characteristics. The state-of-charge determination device 19 is configured to determine the current state of charge of the energy storage system 14 and transmit the current state of charge to the control circuit 18. The state-of-charge determination device 19 may also evaluate the health status of the energy storage system 14 and transmit it to the control circuit 18.

[0027] In the same embodiment of the present invention, the energy storage system 14 comprises a DC electrical converter 141 and an AC / DC converter 142. An AC interface of the AC / DC converter 142 is connected to the feeder link 62 and a DC interface of the AC / DC converter 142 is connected to the DC electrical converter 141, which allows the transfer of power between the feeder link 62 and the DC converter 141.

[0028] FIG. 2 is a schematic diagram of a power generation system 1 according to a second embodiment of the present invention. The second embodiment is the same as the first embodiment except for the structure of the hydro-turbine system 3. In this embodiment, the hydro-turbine system 3 includes a first reversible pump-turbine 31 and a second reversible pump-turbine 32. Each reversible pump-turbine includes an electric machine connected to a connecting link 6. In the operation mode of this embodiment, each reversible pump-turbine exchanges power with the AC grid 2. Therefore, Aepos sent to the control circuit 18 satisfies the relationship Aepos=Aepos1+Aepos2, where Aepos1 and Aepos2 are the actual power setpoints sent to the first turbine 31 and the second turbine 32, respectively. Aepos1 and Aepos2 belong to the safety zones of the individual pump-turbines 31 and 32.

[0029] FIG. 12 illustrates a range of power setpoints for the hydro-turbine system 3 of FIG. 2 based on the water level H of the pump-turbines 31 and 32. The vertical axis represents the power P0 of the turbine system 3, and the horizontal axis represents the water level H. Region 80 represents the range of possible power setpoints for the turbine system 3. Region 80 includes two regions 81 and 82. Region 81 corresponds to the range of possible power setpoints provided by either pump-turbine 31 or pump-turbine 32 individually (in this case, pump-turbines 31 and 32 are the same). Region 82 corresponds to the range of possible power setpoints that can be achieved by both pump-turbines 31 and 32 operating simultaneously. The power setpoint range includes power output setpoints that cannot be reached (and are therefore undesirable for the turbine system 3), as shown in region 83.

[0030] In this configuration, the pump-turbines 31 and 32 can operate in turbine mode or pump mode. One can be shut off. The pump-turbines 31 and 32 can also operate in a combination of these possibilities. In another operating mode of the second embodiment of the present invention, the first reversible pump-turbine 31 operates in pump mode, moving water through a dam. The pump-turbine 31 operates in hydraulic short circuit with the second reversible pump-turbine 32. The second pump-turbine 32 operates in generator mode. This configuration, combined with the transfer of power between the energy storage system 14 and the feeder link 6, allows the turbine system 3 to extend its power setpoint range and generate power for higher and lower power setpoints.

[0031] FIG. 13 shows the operating mode of the power generation system 1 of FIG. 2. The setpoint Reps is received by the control circuit 18 and is shown in the unreachable and therefore undesirable region 83. In this first operating mode of the power generation system 1, it is determined that the energy storage system 14 should be discharged depending on its state of charge. The state of charge is compared, for example, with a threshold value (e.g., 50%) to determine whether the energy storage system 14 should be discharged or charged. The setpoints Aepos1 and Aepos2 are then adjusted to their minimum values. The sum of Aepos = Aepos1 + Aepos2 is greater than the setpoint Reps in the region 82. These setpoints Aepos1 and Aepos2 are sent to the turbines 31 and 32, respectively. The setpoint Epts is set so that the energy storage system 14 is charged, and the turbine system 3 sends charging power to the energy storage system 14. This setpoint Epts is provided to the energy storage system 14. More precisely, both pump-turbines 31 and 32 operate simultaneously in turbine mode. In this case, the setpoint Aepos of the turbine system 3 is the sum of the setpoints Aepos1 and Aepos2 of the pump-turbines 31 and 32, respectively.

[0032] FIG. 14 shows another operating mode of the power generation system 1 of FIG. 2. The setpoint Reps is received by the control circuit 18 and is shown in the unreachable and undesirable region 83. In this second operating mode of the power generation system 1, it is determined that the energy storage system 14 is to be charged depending on its state of charge. The state of charge is compared with, for example, a threshold value (e.g., 50%) to determine whether the energy storage system 14 is to be discharged or charged. In this case, the control circuit 18 determines that the energy storage system 14 is to be charged. The setpoint Aepos1 is set to its maximum value, while Aepos2 is set to 0, which means that the turbine 32 is stopped. Then, Aepos = Aepos1 + Aepos2 is lower than the setpoint Reps in the region 81. This setpoint Aepos is sent to the hydro-turbine system 3. In the region 81, the turbine system 3 operates only the pump-turbine 31 and stops the operation of the pump-turbine 32. Therefore, Aepos is defined only by the setpoint Aepos1 of the pump-turbine 31. The setpoint Aepos2 is 0. The setpoint Epts is set so that the energy storage system 14 is discharged and the energy storage system 14 sends power to the AC grid 2. This setpoint Epts is provided to the energy storage system 14.

[0033] If the setpoint Reps remains in region 83, the control circuit 18 can alternate between the two operating modes (shown in FIGS. 13 and 14) as shown in FIG. 15. FIG. 15 shows the change in the setpoint over time. In this example, the setpoint Reps (dotted line) received by the control circuit 18 remains at the same level in the unreachable and undesirable region 83. The setpoint Aepos is shown with a solid line. The setpoint Epts is shown with a dotted line. Also shown are setpoints Aepos1 and Aepos2, which satisfy the relationship Aepos=Aepos1+Aepos2.

[0034] In the first stage, the energy storage system 14 is charged, so that the setpoint Epts becomes negative and the setpoint Aepos becomes greater than the setpoint Reps, thereby charging the energy storage system 14. Both pump-turbines 31 and 32 operate simultaneously in turbine mode.

[0035] When a predetermined charge level of the energy storage system 14 is reached, the energy storage system 14 must be discharged. As a result, the set values ​​of Epts and Aepos are gradually offset. Therefore, the set value Epts is set positive and the set value Aepos is lower than the set value Reps. Eventually, in turbine mode, only the pump-turbine 31 continues to operate. Therefore, the relationship Aepos=Aepos1 is fulfilled.

[0036] When a predetermined discharge level of the energy storage system 14 is reached, the energy storage system 14 must be charged. As a result, the setpoints Epts and Aepos are gradually offset, and the two pump-turbines 31 and 32 operate simultaneously in turbine mode. As a result, the setpoint Epts is set negative, and the setpoint Aepos is higher than the setpoint Reps. The relationship Aepos=Aepos1+Aepos2 is then satisfied. For both operating modes, the relationship Reps=Aepos1+Aepos2+Epts is established.

[0037] 3 is a schematic diagram of a power generation system 1 according to a third embodiment of the present invention. In this embodiment, the power generation system 1 includes a branch 4 and a branch 8. Branch 4 and branch 8 are connected in parallel between the connection interface 62 and the feeder link 6. Branch 4 is defined as a first supply branch and includes a control switch 41. Branch 8 is defined as a second supply branch and includes a variable frequency converter 5.

[0038] The variable frequency converter 5 comprises an AC / DC converter 11 , a further AC / DC converter 12 , a DC link 13 , a controlled switch 15 and an energy storage system 14 .

[0039] The AC interface of AC / DC converter 11 is connected to connection interface 62, and the AC interface of AC / DC converter 12 is connected to feeder link 6. DC link 13 electrically connects the separate DC interfaces of AC / DC converters 11 and 12, allowing the transfer of power between these DC interfaces.

[0040] The AC / DC converters 11 and 12 are configured to change the flow of current. The AC / DC converters 11 and 12 are controlled by control circuits 16 and 17, respectively. In one mode of the control circuit 16, power is sent from the AC interface of the AC / DC converter 11 to the DC interface of the AC / DC converter 11, and in another mode of the control circuit 16, power is sent from the DC interface of the AC / DC converter 11 to the AC interface of the AC / DC converter 11. In one mode of the control circuit 17, power is sent from the DC interface of the AC / DC converter 12 to the AC interface of the AC / DC converter 12, and in another mode of the control circuit 17, power is sent from the AC interface of the AC / DC converter 12 to the DC interface of the AC / DC converter 12.

[0041] The power generation system 1 further comprises a control circuit 7. The control circuit 7 is configured to control the switch 41 and the switch 15 of the variable frequency converter 5. The control circuit 7 therefore controls the transmission of power between the turbine system 3 and the AC grid 2 via the first branch 4, and the transmission of power between the energy storage system 14 and the feeder link 6.

[0042] The control circuit 7 has a control mode in which it simultaneously closes the switches 41 and 15 to connect the connection interface 62 to the feeder link 6. In this mode, the control circuit 7 allows power to be sent from the turbine system 3 to the AC grid 2 via the first branch 4 (or vice versa, from the AC grid 2 to the turbine system 3). Furthermore, the control circuit 18 controls the transfer of power between the energy storage system 14 and the AC grid 2 or the turbine system 3 via the branch 8. Indeed, the AC / DC converters 11 and 12 configured to transfer power from the respective DC interface to the AC interface when discharging of the energy storage system 14 is required; or When charging of the energy storage system 14 is required, power is transferred from the respective AC interface to the DC interface to transfer power from the turbine system 3 or the AC grid 2 to the energy storage system 14 .

[0043] 4 is a schematic diagram of a power generation system 1 according to a fourth embodiment of the present invention. This embodiment is the same as the third embodiment except for the structure of the energy storage device 14. In this embodiment, the energy storage system 14 includes a DC electrical converter 141 and a DC / DC converter 143. The DC / DC converter 143 electrically connects the energy storage system 14 to the DC interfaces of the AC / DC converters 11 and 12. The DC / DC converter 143 is configured to adjust the voltage levels between the storage device 141 and the DC interfaces of the AC / DC converters 11 and 12.

[0044] In embodiments of the present invention, the energy storage system 14 may comprise a storage device selected from the group including a supercapacitor, a fuel cell, an electrochemical battery, an electric motor driving a flywheel, an air compressor, and electromagnetic storage.

[0045] In the case of electrochemical batteries, the control circuit 18 monitors the charging and discharging of the DC-to-electrical converter 141 and sets the power transfer setpoint Epts to maintain the DC-to-electrical converter 141 in a state of charge or within a suitable charging range, thereby minimizing wear and improving battery life. Such a charging range may, for example, cover 20% of the total capacity. The limits of this charging range are set according to the battery's characteristics (e.g., the chemistry used). For example, such a range may be between 40 and 60% for a lithium-ion battery.

Claims

1. A power generation system (1), comprising: a water turbine system (3) with an electric machine, the water turbine system (3) having specific undesirable and safe power output setpoints; an energy storage system (14); a feeder link (6) connected to the energy storage system (14) and the electric machine of the hydro-turbine system (3), the feeder link (6) having a connection interface (62) for connection to an AC grid (2); a state-of-charge determination device (19) configured to determine the state of charge of the energy storage system (14); Equipped with The system (1) further comprises: a control circuit (18) configured to control the transfer of power between the feeder link (6) and the energy storage system (14) by selectively controlling charging or discharging of the energy storage system (14), the control circuit (18) being configured to receive a power setpoint value Reps; The control circuit further comprises: configured to determine that the received power setpoint Reps belongs to the undesired power output setpoint; configured to generate a power transmission setpoint Epts of the energy storage system (14) and an actual power output setpoint Aepos of the hydro-turbine system (3) belonging to the safe power output setpoint, the setpoint satisfying the relationship Reps=Epts+Aepos; The power transfer setpoint Epts is set in response to a determined state of charge of the energy storage system (14). Power generation system (1).

2. 2. The power generation system (1) of claim 1, wherein the energy storage system (14) comprises a DC-to-DC converter (141), an AC / DC converter (142) having an AC interface connected to the feeder link (6), and a DC interface connected to the DC-to-DC converter (141).

3. 3. The power generation system (1) of claim 2, wherein the energy storage system (14) comprises a DC / DC converter (143) configured to change a voltage level between the DC electrical converter (141) and the DC interface of the AC / DC converter (142).

4. 4. The power generation system (1) according to claim 2 or 3, wherein the DC-to-electrical converter (141) comprises a device selected from the group comprising a supercapacitor, a fuel cell, an electrochemical battery, an electric motor driving a flywheel, an air compressor, and an electromagnetic storage.

5. 5. The power generation system (1) of claim 4, wherein the DC / DC converter (141) is an electrochemical battery having a state of charge range for which its life is optimized, and the control circuit (18) is configured to set the power transfer setpoint Epts so that the state of charge of the electrochemical battery (141) falls within the charge range.

6. The power generation system (1) according to any one of claims 1 to 5, wherein the undesirable power output setpoints and the safe power output setpoints are defined for a plurality of different values ​​of water level in the hydro-turbine system (3).

7. The power generation system (1) of any one of claims 1 to 6, wherein the particular undesirable power output setpoint is a power setpoint that the hydro-turbine system (3) cannot reach.

8. 8. The power generation system (1) according to claim 1, wherein the control circuit (18) causes charging of the energy storage device (14) when the set value Reps increases above a predetermined threshold level and the state of charge of the energy storage device (14) is below a predetermined threshold.

9. The power generation system (1) according to any one of claims 1 to 8, wherein the control circuit (18) causes the discharge of the energy storage device (14) when the set value Reps decreases below a predetermined threshold level and when a state of charge of the energy storage device (14) exceeds a predetermined threshold.

10. The power generation system (1) according to any one of claims 1 to 9, wherein the water turbine system (3) comprises a plurality of water turbines, each water turbine comprising a respective electric machine connected to the feeder link (6).

11. The water turbine system (3) comprises: a number N of pump-turbines (31, 32), each with an index i, operating in hydraulic short circuit and operating at a respective actual power output setpoint Aeposi, The water-turbine system (3) is configured to selectively operate at least one of the pump-turbines in a turbine mode and at least one other of the pump-turbines in a pump mode; Aepos = ΣAeposi, where i ranges from 1 to N; The power generation system (1) according to any one of claims 1 to 10.

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