Full-power variable-speed pumped storage control method, device and system considering electrical losses

Abstract

The present invention discloses a full-power variable-speed pumped storage control method, device and system considering electrical losses, belonging to the technical field of pumped storage control, the control method comprising: using each electrical efficiency characteristic curve to correct the hydraulic efficiency characteristic curve under the same operating condition, to obtain the target efficiency characteristic curve under each operating condition; recording the speed corresponding to the highest efficiency point in each target efficiency characteristic curve as the optimal speed, to obtain an optimal speed lookup table recording the optimal speed under each operating condition; finding the corresponding current optimal speed from the optimal speed lookup table according to the current operating condition, so as to perform machine-side control and water-side control. The present invention uses the optimal speed lookup table that takes into account the electrical efficiency in the electric energy conversion process to perform full-power variable-speed pumped storage control, which can make the entire full-power variable-speed pumped storage system operate at the true highest efficiency point, thereby improving the overall operating efficiency of the system.

Description

Technical Field

[0001] The present invention belongs to the technical field of pumped storage control, and more specifically, relates to a full-power variable-speed pumped storage control method, device and system taking electrical losses into consideration. Background Art

[0002] Variable speed pumped storage is an important way to solve the problems of reduced grid stability caused by large-scale grid connection of highly random and intermittent energy sources such as wind power and photovoltaics, and can effectively improve the grid's absorption level of new energy. The full-power variable speed pumped storage unit achieves decoupling of the synchronous motor from the grid through a full-power converter, and has the advantages of a wide power regulation range, fast response, and high operational flexibility. It is one of the important future development directions of pumped storage power stations.

[0003] Usually, variable-speed pumped storage units adopt power priority control to achieve rapid response to power changes on the user side, but this ignores the impact of unit speed changes on system stability. If the response of the pump-turbine output mechanical torque is too slow, the pump-turbine output torque will not be able to balance with the electromagnetic torque during the speed drop process, and the system speed will continue to drop below the threshold, eventually causing the collapse of the entire system. At present, the optimal speed command of the variable-speed pumped storage system is obtained by table lookup to enable the entire system to operate at the highest efficiency point.

[0004] However, currently variable speed pumped storage units only consider hydraulic losses, while ignoring the power loss in the process of electric energy conversion. This may result in the system not running at the optimal system efficiency point, although it runs at the optimal hydraulic efficiency point through table lookup, causing the actual operating efficiency of the system to deviate from the true optimal efficiency point of the system. Summary of the invention

[0005] In view of the above defects or improvement needs of the prior art, the present invention provides a full-power variable-speed pumped storage control method, device and system taking into account electrical losses, with the aim of solving the technical problem that the actual operating efficiency deviates from the true optimal efficiency point during the control process of the variable-speed pumped storage unit, resulting in low control efficiency.

[0006] To achieve the above object, according to one aspect of the present invention, a full-power variable-speed pumped storage control method considering electrical losses is provided, comprising:

[0007] Construct a hydraulic efficiency characteristic curve that represents the mapping relationship between the rotation speed and hydraulic efficiency under various operating conditions;

[0008] Constructing an electrical efficiency characteristic curve representing the mapping relationship between the rotation speed and the electrical efficiency under each of the operating conditions;

[0009] Using each of the electrical efficiency characteristic curves to calibrate the hydraulic efficiency characteristic curve under the same operating condition, to obtain a target efficiency characteristic curve under each of the operating conditions;

[0010] Recording the speed corresponding to the highest efficiency point in each target efficiency characteristic curve as the optimal speed, so as to obtain an optimal speed lookup table recording the optimal speed under each operating condition;

[0011] According to the current operating conditions, the corresponding current optimal speed is found from the optimal speed lookup table; the current optimal speed is sent as a command value to the machine-side controller to control the motor to reach the specified speed; the optimal guide vane opening is calculated according to the current optimal speed and sent as a command value to the water-side speed governor to control the servo system so that the guide vane reaches the specified opening, thereby realizing control of the system output power.

[0012] In one embodiment, constructing a hydraulic efficiency characteristic curve representing the mapping relationship between the rotation speed and the hydraulic efficiency under various operating conditions includes:

[0013] The water head, speed and power of the pump-turbine under different operating conditions are measured, and the hydraulic efficiency under different operating conditions corresponding to different water heads and speeds is calculated, so as to draw a hydraulic efficiency characteristic curve representing the mapping relationship between the speed and the hydraulic efficiency under each of the operating conditions.

[0014] In one embodiment, the step of constructing an electrical efficiency characteristic curve representing a mapping relationship between a rotation speed and electrical efficiency under each of the operating conditions includes:

[0015] In the pumping condition, the system state parameters under each of the operating conditions are input into the formula , the electrical efficiency η under each of the operating conditions is obtained e The electrical efficiency characteristic curve of the mapping relationship with the speed n;

[0016] Among them, P ref is the active power command on the grid side, P m is the mechanical power of the pump turbine, B is the damping coefficient, Ψ s is the stator flux, r s is the stator current, p inv is the switching loss of the inverter.

[0017] In one embodiment, the electrical efficiency η in the electrical efficiency characteristic curve under the pumping condition is e P m With P ref ratio.

[0018] In one embodiment, the step of constructing an electrical efficiency characteristic curve representing a mapping relationship between a rotation speed and electrical efficiency under each of the operating conditions includes:

[0019] In the power generation condition, the system state parameters under each of the operating conditions are input into the formula , the electrical efficiency η under each of the operating conditions is obtained e The electrical efficiency characteristic curve of the mapping relationship with the speed n;

[0020] Among them, P ref is the active power command on the grid side, P m is the mechanical power of the pump turbine, B is the damping coefficient, Ψ s is the stator flux, r s is the stator resistance, p inv is the switching loss of the inverter.

[0021] In one embodiment, the electrical efficiency characteristic curve of the power generation condition is e P ref With P m ratio.

[0022] In one embodiment, the method of using each of the electrical efficiency characteristic curves to calibrate the hydraulic efficiency characteristic curve under the same operating condition includes:

[0023] The electrical efficiency in the electrical efficiency characteristic curve under each of the operating conditions is multiplied by the hydraulic efficiency under the hydraulic efficiency characteristic curve under the same operating condition to obtain the target efficiency under each of the operating conditions, and then to obtain the target efficiency characteristic curve under each of the operating conditions.

[0024] According to another aspect of the present invention, there is provided a full-power variable-speed pumped storage control device taking into account electrical losses, comprising:

[0025] The first construction module is used to construct a hydraulic efficiency characteristic curve representing the mapping relationship between the rotation speed and the hydraulic efficiency under various operating conditions;

[0026] A second construction module is used to construct an electrical efficiency characteristic curve representing the mapping relationship between the rotation speed and the electrical efficiency under each of the operating conditions;

[0027] A correction module, used to use each of the electrical efficiency characteristic curves to correct the hydraulic efficiency characteristic curve under the same operating condition to obtain a target efficiency characteristic curve under each of the operating conditions;

[0028] An acquisition module, used for recording the speed corresponding to the highest efficiency point in each of the target efficiency characteristic curves as the optimal speed, so as to obtain an optimal speed lookup table recording the optimal speed under each of the operating conditions;

[0029] A control module is used to find the corresponding current optimal speed from the optimal speed lookup table according to the current operating conditions; send the current optimal speed as a command value to the machine-side controller so that it controls the motor to reach a specified speed; calculate the optimal guide vane opening according to the current optimal speed and send it as a command value to the water-side speed governor so that it controls the servo system so that the guide vane reaches the specified opening, thereby realizing control of the system output power.

[0030] According to another aspect of the present invention, a full-power variable-speed pumped storage control system taking electrical losses into consideration is provided, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the described method when executing the computer program.

[0031] According to another aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method described above are implemented.

[0032] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0033] (1) The present invention provides a full-power variable-speed pumped storage control method that takes electrical losses into consideration, wherein each of the electrical efficiency characteristic curves is used to calibrate the hydraulic efficiency characteristic curve under the same operating condition to obtain a target efficiency characteristic curve under each of the operating conditions; the speed corresponding to the highest efficiency point in each of the target efficiency characteristic curves is recorded as the optimal speed to obtain an optimal speed lookup table that records the optimal speed under each of the operating conditions; the corresponding current optimal speed is found from the optimal speed lookup table according to the current operating condition, thereby performing machine-side control and water-side control. The present invention uses an optimal speed lookup table that takes into account the electrical efficiency in the electric energy conversion process to perform a full-power variable-speed pumped storage control method, which can enable the entire full-power variable-speed pumped storage system to operate at the true highest efficiency point, thereby improving control efficiency.

[0034] (2) This scheme measures the head, speed and power of the pump-turbine under different operating conditions to obtain the hydraulic efficiency corresponding to different heads and speeds. This method takes into account the operating status of the pump-turbine under different operating conditions and realizes the data acquisition of various operating conditions, so as to facilitate the subsequent establishment of a high-precision optimal speed lookup table.

[0035] (3) This scheme uses the pumping condition. The electrical efficiency characteristic curve is constructed. This method takes into account the active power loss of the motor and converter under pumping conditions and realizes the accurate calculation of the electrical efficiency under pumping conditions.

[0036] (4) The electrical efficiency η in the electrical efficiency characteristic curve under the pumping condition described in this scheme e P m With P ref This method takes into account the active power flow direction under pumping conditions and realizes the accurate establishment of the electrical efficiency characteristic curve under pumping conditions.

[0037] (5) Under power generation conditions, this scheme uses The electrical efficiency characteristic curve is constructed. This method takes into account the active power loss of the motor and converter under power generation conditions and realizes the accurate calculation of the electrical efficiency under power generation conditions.

[0038] (6) The electrical efficiency η in the electrical efficiency characteristic curve under the power generation conditions described in this scheme e P ref With P m This method takes into account the active power flow direction under power generation conditions and realizes the accurate establishment of the electrical efficiency characteristic curve under power generation conditions.

[0039] (7) In this scheme, the electrical efficiency in the electrical efficiency characteristic curve under each of the operating conditions is multiplied by the hydraulic efficiency under the hydraulic efficiency characteristic curve under the same operating condition to obtain the target efficiency under each of the operating conditions. This method takes into account the deviation between the maximum operating efficiency and the maximum hydraulic efficiency of the system. The maximum operating efficiency of the system is corrected by calculating the electrical efficiency, thereby achieving the full-power variable-speed pumped storage system being able to operate at the true maximum efficiency point under any operating condition. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a flow chart of designing an optimal speed lookup table taking electrical efficiency into consideration provided by an embodiment of the present invention.

[0041] Figure 2a It is a characteristic curve diagram that only considers hydraulic efficiency provided by an embodiment of the present invention.

[0042] Figure 2b This is a schematic diagram of searching for the optimal rotation speed that only considers hydraulic efficiency provided by an embodiment of the present invention.

[0043] Figure 3a It is a characteristic curve diagram considering electrical efficiency provided by an embodiment of the present invention.

[0044] Figure 3b It is a schematic diagram of searching for the corrected optimal rotation speed provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0046] In the prior art, the system control method of full-power variable-speed pumped storage can be divided into speed priority control and power priority control according to the control target. For power priority control, although the actual power on the grid side can always quickly track the power command, this instantaneous increase in energy is extracted from the kinetic energy of the rotor. If the response of the pump turbine is too slow, the speed will fall below the threshold, eventually leading to system collapse. Although the speed priority control strategy sacrifices the ability to respond quickly to power, the system speed is always controllable and will not collapse due to too low a speed. Therefore, from the perspective of stability, the present invention adopts a speed priority control method.

[0047] The control objectives of each part of the speed priority control pumping condition and power generation condition are exactly the same, that is: the machine-side converter is responsible for controlling the motor speed, the grid-side converter is responsible for controlling the DC bus voltage stability to achieve active power transmission, and the water-side speed governor is responsible for controlling the guide vane opening to control the output power of the turbine. It should be noted that due to the affinity effect of the pumping condition, the power is regulated by the speed under the pumping condition, and the control of the guide vane opening only adjusts the pumping efficiency of the system, and has no effect on the power regulation.

[0048] In one of the embodiments, the specific implementation process of the full-power variable speed pumped storage control method considering electrical loss provided by the present invention is introduced. This embodiment provides a full-power variable speed pumped storage control method considering electrical loss, such as Figure 1As shown, it includes: S1-S5. S1: construct a hydraulic efficiency characteristic curve that characterizes the mapping relationship between the speed and the hydraulic efficiency under various operating conditions; S2: construct an electrical efficiency characteristic curve that characterizes the mapping relationship between the speed and the electrical efficiency under various operating conditions; S3: use each electrical efficiency characteristic curve to correct the hydraulic efficiency characteristic curve under the same operating condition to obtain the target efficiency characteristic curve under each operating condition; S4: record the speed corresponding to the highest efficiency point in each target efficiency characteristic curve as the optimal speed, so as to obtain an optimal speed lookup table that records the optimal speed under various operating conditions; S5: find the corresponding current optimal speed from the optimal speed lookup table according to the current operating condition; send the current optimal speed as an instruction value to the machine-side controller to control the motor to reach the specified speed; calculate the optimal guide vane opening according to the current optimal speed and send it as an instruction value to the water-side speed regulator to control the servo system so that the guide vane reaches the specified opening, thereby realizing the control of the system output power.

[0049] It should be understood that although Figure 1 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 1 At least part of the steps may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least part of the sub-steps or stages of other steps.

[0050] The present invention adopts speed priority control, and the water side control method adopts guide vane opening control, that is, the water side speed governor controls the servo system so that the guide vane opening can track the optimal guide vane opening instruction.

[0051] Among them, the machine-side control method adopts stator flux orientation control. Stator flux orientation can ensure that the stator side is always at unity power factor. At the same time, since the excitation current is adjustable, stator flux orientation is completely equivalent to maximum torque current ratio control, which not only realizes unity power factor control, effectively reduces the converter capacity, but also realizes maximum torque current ratio control, and improves the power density of the motor. The optimal speed command of the machine-side controller and the optimal guide vane opening command of the water-side speed regulator need to be generated and issued by the system-level controller, and the system-level controller gives the optimal speed according to the current operating conditions and the built-in optimal speed before operation, and sends it as a command to the machine-side controller. At the same time, since the pump turbine only needs to know any three of the physical quantities to calculate other related physical quantities, the optimal guide vane opening can be calculated according to the current optimal speed, head and power, and it is sent as a command to the water-side speed regulator. In addition, the grid-side control method adopts the most commonly used dual closed-loop control structure of the DC bus voltage outer loop and the grid-side current inner loop. Since this control method is widely used, it will not be repeated here.

[0052] In one embodiment, if Figure 2a and Figure 2b , S1 includes: measuring the water head, speed and power of the pump turbine under different operating conditions, calculating the hydraulic efficiency under different operating conditions corresponding to different water heads and speeds, and drawing a hydraulic efficiency characteristic curve representing the mapping relationship between the speed and the hydraulic efficiency under various operating conditions.

[0053] Since the key physical quantities of a pump turbine include water head, speed, guide vane opening, flow rate and power, other related physical quantities can be calculated by knowing any three of them. For example, efficiency can be uniquely determined by water head, speed and flow rate, by speed, power and water head, or by guide vane opening, speed and power.

[0054] Specifically, the optimal speed lookup table corresponding to the hydraulic efficiency characteristic curve is established before the system is put into operation. The establishment method is: measure the head, speed and power of the pump turbine under different operating conditions, and calculate the corresponding operating efficiency under the operating conditions, draw the efficiency characteristic curves about the speed under different heads and powers, which constitute a set of efficiency characteristic curve clusters. The speed corresponding to the maximum efficiency point of each efficiency characteristic curve is recorded as the optimal speed. All optimal speeds constitute the optimal speed table about head and power. Therefore, only the head and power need to be obtained to obtain the speed corresponding to the maximum operating efficiency of the system.

[0055] In one embodiment, S2 includes: in the pumping condition, the system state parameters under each operating condition are input into the formula , the electrical efficiency η is obtained under various operating conditions eThe electrical efficiency characteristic curve of the mapping relationship between and the speed n; wherein, P ref is the active power instruction on the grid side, P m is the mechanical power of the pump turbine, B is the damping coefficient, Ψ s is the stator flux, r s is the stator resistance, p inv is the switching loss of the inverter.

[0056] The electrical loss is mainly reflected in the heat loss of the motor stator resistance, the friction loss of the damping torque and the switching loss of the converter. Among them, the switching loss of the converter can be considered to be related to the switching frequency, and the switching frequency is constant during the entire operation process, so the switching loss of the inverter is approximately fixed, and its value is generally 2% of the rated power of the system. Therefore, only the heat loss of the stator resistance and the friction loss of the damping torque need to be considered additionally. The electrical efficiency of the unit will be calculated below.

[0057] For the motor, due to the stator flux orientation, the stator voltage vector, stator current vector and stator back electromotive force vector completely coincide. Using the motor convention, the steady-state expression of the stator voltage vector is: u s = r s i s + nΨ s ;in, u s is the stator voltage, r s is the stator resistance, i s is the stator current, n is the motor speed, Ψ s is the stator flux.

[0058] The steady-state motion equation of the motor is expressed as: T e =T m +Bn ; In the formula, T e is the electromagnetic torque, T m is the mechanical torque, B is the damping coefficient.

[0059] Since the stator current depends on the load size, combining the previous electromagnetic torque expression and the steady-state motion equation, we can get: ; Then the mechanical power output of the pump turbine under pumping conditions is expressed as: ;

[0060] Therefore, the expression of the power balance equation is:

[0061] .

[0062] The relationship between output power and power command can be rewritten using efficiency as follows: η e =P m / P ref , then the expression of the power balance equation can be rewritten as:

[0063] ;

[0064] It can be seen that the above formula only contains two unknown quantities, the speed and the electrical efficiency, so a characteristic curve about the electrical efficiency and the speed can be obtained, such as Figure 3a and Figure 3b As shown, it is recorded as η e Under the current head and power command, there is a characteristic curve of hydraulic efficiency and speed. This efficiency characteristic curve is the hydraulic efficiency curve of the pump turbine, which can also be regarded as the system efficiency curve ignoring electrical losses, recorded as η 2 The optimal speed corresponding to the highest efficiency point is recorded as n opt2 The curve obtained by multiplying this characteristic curve with the electrical efficiency curve is called the corrected efficiency characteristic curve, denoted as η ' 2. Finally, find the speed corresponding to the highest efficiency point on the corrected efficiency curve, which is the corrected optimal speed n 'opt2. By continuously changing the water head and power conditions and repeating the above efficiency optimization operation, an optimal speed correction lookup table related to the water head and power instructions can be obtained.

[0065] In one embodiment, the electrical efficiency characteristic curve under pumping conditions is e P m With P ref ratio.

[0066] In one embodiment, S2 includes: in the power generation condition, the system state parameters under each operating condition are input into the formula , and the electrical efficiency under various operating conditions is obtained ηe With speed n The electrical efficiency characteristic curve of the mapping relationship between P ref is the active power instruction on the grid side, P m is the mechanical power of the pump turbine, B is the damping coefficient, Ψ s is the stator flux, r s is the stator resistance, p inv is the switching loss of the inverter.

[0067] The power generation conditions are basically similar to the pumping conditions, but there are still slight differences, which are briefly introduced here.

[0068] In one embodiment, the electrical efficiency characteristic curve of the power generation condition is e P ref With P m ratio.

[0069] Since the power flow direction of the power generation condition is opposite to that of the pumping condition, the stator current is reversed, so the steady-state expression of the stator voltage vector is: u s = - r s i s + nΨ s ; The steady-state expression of electromagnetic torque is: e =T m -Bn ; The steady-state expression of stator current is: i s = ( T m -Bn ) / Ψ s = ( P m - Bn 2 ) / nΨ s ; The power balance equation under power generation conditions is: P ref =P m - p inv - r si s 2 - Bn 2 ; The expression of electrical efficiency is: η e =P ref / P m ; Then the power balance equation can be rewritten as:

[0070] ;

[0071] The process of making the optimal speed correction lookup table under power generation conditions is exactly the same as that under pumping conditions. To save space, it will not be repeated here.

[0072] In one embodiment, S3 includes: multiplying the electrical efficiency in the electrical efficiency characteristic curve under each operating condition by the hydraulic efficiency in the hydraulic efficiency characteristic curve under the same operating condition to obtain the target efficiency under each operating condition, and then obtaining the target efficiency characteristic curve under each operating condition.

[0073] The efficiency obtained by the optimal speed lookup table corresponding to the hydraulic efficiency characteristic curve is only the hydraulic efficiency, and does not take into account the electrical efficiency in the process of power conversion, which may cause the system to not operate at the true highest efficiency point, resulting in energy waste. The following is a design method for the corrected optimal speed lookup table considering electrical losses. According to physical quantities such as the system switching frequency, motor stator resistance, and damping torque, the electrical efficiency characteristic curve about the speed under the current operating conditions can be calculated. Similarly, different heads and powers constitute a group of electrical efficiency curve clusters. Multiply the hydraulic efficiency curve with the same head and power with the electrical efficiency curve to obtain the corrected efficiency characteristic curve, record the speed corresponding to the highest efficiency point of each corrected efficiency characteristic curve as the corrected optimal speed, and generate a corrected optimal speed lookup table.

[0074] In summary, the present invention is based on the existing full-power variable-speed pumped storage control method, adopts speed priority control to improve the stability of the system, realizes the minimization design of the converter and the motor through stator flux orientation, and realizes the operation of the entire system at the highest hydraulic efficiency point through the optimal speed lookup table method. In addition, this patent also takes electrical efficiency into consideration, which can further improve the actual operating efficiency of the system. Therefore, this control method is particularly suitable for full-power variable-speed pumped storage systems with large power levels or high electrical losses.

[0075] In one of the embodiments, a full-power variable-speed pumped storage control device taking electrical losses into consideration is provided, comprising: a first building module, a second building module, a correction module, an acquisition module and a control module.

[0076] The first construction module is used to construct a hydraulic efficiency characteristic curve representing the mapping relationship between the rotation speed and the hydraulic efficiency under various operating conditions;

[0077] The second construction module is used to construct an electrical efficiency characteristic curve representing the mapping relationship between the rotation speed and the electrical efficiency under various operating conditions;

[0078] A correction module, used to use each electrical efficiency characteristic curve to correct the hydraulic efficiency characteristic curve under the same operating condition to obtain a target efficiency characteristic curve under each operating condition;

[0079] An acquisition module, used to record the speed corresponding to the highest efficiency point in each target efficiency characteristic curve as the optimal speed, so as to obtain an optimal speed lookup table recording the optimal speed under various operating conditions;

[0080] The control module is used to find the corresponding current optimal speed from the optimal speed lookup table according to the current operating conditions; send the current optimal speed as a command value to the machine-side controller to control the motor to reach the specified speed; calculate the optimal guide vane opening according to the current optimal speed and send it as a command value to the water-side speed governor to control the servo system so that the guide vane reaches the specified opening, thereby realizing the control of the system output power.

[0081] The division of the various modules in the above-mentioned full-power variable speed pumped storage control device is only for illustration. In other embodiments, the full-power variable speed pumped storage control device can be divided into different modules as needed to complete all or part of the functions of the above-mentioned full-power variable speed pumped storage control device.

[0082] For the specific definition of the full-power variable speed pumped storage control device, please refer to the definition of the full-power variable speed pumped storage control method above, which will not be repeated here. Each module in the above-mentioned full-power variable speed pumped storage control device can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0083] In one of the embodiments, a full-power variable-speed pumped storage control system taking electrical losses into consideration is provided, comprising a memory and a processor, wherein the memory stores a computer program, and the steps of the method are implemented when the processor executes the computer program.

[0084] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored, and the steps of the method are implemented when the computer program is executed by a processor.

[0085] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A full-power variable speed pumped storage control method considering electrical losses, characterized in that: include: Construct a hydraulic efficiency characteristic curve that represents the mapping relationship between the rotation speed and hydraulic efficiency under various operating conditions; Constructing an electrical efficiency characteristic curve representing the mapping relationship between the rotation speed and the electrical efficiency under each of the operating conditions; Using each of the electrical efficiency characteristic curves to calibrate the hydraulic efficiency characteristic curve under the same operating condition, to obtain a target efficiency characteristic curve under each of the operating conditions; Recording the speed corresponding to the highest efficiency point in each target efficiency characteristic curve as the optimal speed, so as to obtain an optimal speed lookup table recording the optimal speed under each operating condition; Find the corresponding current optimal speed from the optimal speed lookup table according to the current operating condition; The current optimal speed is sent as a command value to the machine-side controller to control the motor to reach the specified speed; the optimal guide vane opening is calculated according to the current optimal speed and sent as a command value to the water-side speed governor to control the servo system so that the guide vane reaches the specified opening, thereby achieving control of the system output power; The electrical efficiency characteristic curve representing the mapping relationship between the rotation speed and the electrical efficiency under each of the operating conditions is constructed, including: in the pumping condition, the system state parameters under each operating condition are input into the formula , the electrical efficiency η under each of the operating conditions is obtained e The electrical efficiency characteristic curve of the mapping relationship between P and speed n; ref is the active power command on the grid side, P m is the mechanical power of the pump turbine, B is the damping coefficient, Ψ s is the stator flux, r s is the stator resistance, p inv is the switching loss of the inverter; the electrical efficiency η in the electrical efficiency characteristic curve under the pumping condition e P m With P ref The ratio of The construction of the electrical efficiency characteristic curve representing the mapping relationship between the rotation speed and the electrical efficiency under each of the operating conditions comprises: in the power generation condition, the system state parameters under each of the operating conditions are input into the formula , the electrical efficiency η under each of the operating conditions is obtained e The electrical efficiency characteristic curve of the mapping relationship between P and speed n; ref is the active power command on the grid side, P m is the mechanical power of the pump turbine, B is the damping coefficient, Ψ s is the stator flux, r s is the stator resistance, p inv is the switching loss of the inverter; the electrical efficiency η in the electrical efficiency characteristic curve of the power generation condition e P ref With P m ratio.

2. The full-power variable speed pumped storage control method considering electrical losses as claimed in claim 1, characterized in that: The construction of the hydraulic efficiency characteristic curve representing the mapping relationship between the rotation speed and the hydraulic efficiency under various operating conditions includes: The water head, speed and power of the pump-turbine under different operating conditions are measured, and the hydraulic efficiency under different operating conditions corresponding to different water heads and speeds is calculated, so as to draw a hydraulic efficiency characteristic curve representing the mapping relationship between the speed and the hydraulic efficiency under each of the operating conditions.

3. The full-power variable speed pumped storage control method considering electrical loss as claimed in claim 1, characterized in that: The method of using each of the electrical efficiency characteristic curves to calibrate the hydraulic efficiency characteristic curve under the same operating conditions includes: The electrical efficiency in the electrical efficiency characteristic curve under each of the operating conditions is multiplied by the hydraulic efficiency under the hydraulic efficiency characteristic curve under the same operating condition to obtain the target efficiency under each of the operating conditions, and then to obtain the target efficiency characteristic curve under each of the operating conditions.

4. A full-power variable-speed pumped storage control device taking electrical losses into consideration, characterized in that: include: The first construction module is used to construct a hydraulic efficiency characteristic curve representing the mapping relationship between the rotation speed and the hydraulic efficiency under various operating conditions; A second construction module is used to construct an electrical efficiency characteristic curve representing the mapping relationship between the rotation speed and the electrical efficiency under each of the operating conditions; The electrical efficiency characteristic curve representing the mapping relationship between the rotation speed and the electrical efficiency under each of the operating conditions is constructed, including: in the pumping condition, the system state parameters under each operating condition are input into the formula , the electrical efficiency η under each of the operating conditions is obtained e The electrical efficiency characteristic curve of the mapping relationship between P and speed n; ref is the active power command on the grid side, P m is the mechanical power of the pump turbine, B is the damping coefficient, Ψ s is the stator flux, r s is the stator resistance, p inv is the switching loss of the inverter; the electrical efficiency η in the electrical efficiency characteristic curve under the pumping condition e P m With P ref The ratio of The construction of the electrical efficiency characteristic curve representing the mapping relationship between the rotation speed and the electrical efficiency under each of the operating conditions comprises: in the power generation condition, the system state parameters under each of the operating conditions are input into the formula , the electrical efficiency η under each of the operating conditions is obtained e The electrical efficiency characteristic curve of the mapping relationship between P and speed n; ref is the active power command on the grid side, P m is the mechanical power of the pump turbine, B is the damping coefficient, Ψ s is the stator flux, r s is the stator resistance, p inv is the switching loss of the inverter; the electrical efficiency η in the electrical efficiency characteristic curve of the power generation condition e P ref With P m The ratio of A correction module, used to use each of the electrical efficiency characteristic curves to correct the hydraulic efficiency characteristic curve under the same operating condition to obtain a target efficiency characteristic curve under each of the operating conditions; An acquisition module, used for recording the speed corresponding to the highest efficiency point in each of the target efficiency characteristic curves as the optimal speed, so as to obtain an optimal speed lookup table recording the optimal speed under each of the operating conditions; A control module is used to find the corresponding current optimal speed from the optimal speed lookup table according to the current operating conditions; send the current optimal speed as a command value to the machine-side controller so that it controls the motor to reach a specified speed; calculate the optimal guide vane opening according to the current optimal speed and send it as a command value to the water-side speed governor so that it controls the servo system so that the guide vane reaches the specified opening, thereby realizing control of the system output power.

5. A full-power variable-speed pumped storage control system taking into account electrical losses, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 3 are implemented.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 3 are implemented.

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