Method and system for adjusting three-machine type pumped storage unit

Abstract

The invention discloses a three-machine type pumped storage unit adjusting method and system, and the method comprises the steps: determining different working conditions of a three-machine type pumped storage unit based on a reference power value, and determining different working condition distribution coefficients based on the different working conditions; determining a water turbine working condition distribution coefficient based on the water turbine working condition, determining a hydraulic short-circuit working condition distribution coefficient based on the hydraulic short-circuit working condition, determining a water pump working condition distribution coefficient based on the water pump working condition, and determining different water turbine guide vane opening values and water pump guide vane opening values based on the distribution coefficients of different working conditions; or determining the guide vane opening values of the water turbine and the water pump based on the deviation between the actual frequency and the standard frequency of the system; the synchronous motor output power of the three-machine type pumped storage unit is adjusted based on the water pump guide vane opening value and the water turbine guide vane opening value, the output or absorption power value of the unit is automatically adjusted with the reference power value or the frequency deviation as input, the load requirement of a power grid is met, and the stable power grid frequency is kept.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of pumped storage, and particularly relates to a three-machine pumped storage unit regulating method and system. BACKGROUND

[0002] With the increasing proportion of renewable energy, with the grid connection of large-scale renewable energy (RES), the inertia of the power system is decreasing, and in such a low inertia system, it may cause significant frequency deviation. Pumped storage power stations can solve the intermittency and instability problems of new energy generation. New energy such as solar and wind energy is greatly affected by weather conditions, and the power generation output has uncertainty. Pumped storage power stations can start or stop operation at any time according to the demand of the power grid, adjust the power output, make up for the insufficient or excess output of new energy generation, and thus maintain the balance of power supply and demand. In addition, three-machine pumped storage units can provide additional synchronous inertia and primary and secondary frequency modulation services.

[0003] Conventional pumped storage units may need longer time to convert working conditions, as the working state and operating parameters of the equipment need to be adjusted. This may affect the rapid response requirements of the power grid, especially in the case of the need for rapid adjustment of power output.

[0004] Three-machine pumped storage technology is of great significance for increasing the flexibility of the power grid, the high water head difference between the upper and lower reservoirs, and the rapid response of the power grid command. And the three-machine pumped storage unit has simple structure, adopts conventional water pump, impulse water turbine and synchronous motor. The three-machine pumped storage unit is quite different from the conventional pumped storage unit, and its control also has great changes, especially the regulating system control under the water power short circuit mode. At present, there is a lack of control strategy with high reliability and complete functions in the three-machine pumped storage technology. SUMMARY

[0005] The main purpose of the present application is to provide a three-machine pumped storage unit regulating method and system, which aims to solve the technical problem of the lack of control strategy with high reliability and complete functions in the three-machine pumped storage technology.

[0006] To achieve the above-mentioned purpose, the present application provides a three-machine pumped storage unit regulation method, comprising: obtaining a reference power value of the power grid, wherein the reference power value is equal to a target power value of the power grid; obtaining a system frequency deviation, wherein the system frequency deviation is a deviation between an actual system frequency and a standard frequency; determining different operating conditions of the three-machine pumped storage unit based on the reference power value, and determining different operating condition allocation coefficients based on the different operating conditions, wherein the different operating conditions include a turbine operating condition, a hydraulic short-circuit operating condition, and a water pump operating condition, wherein the turbine operates alone under the turbine operating condition, the pump operates alone under the water pump operating condition, and the turbine and the pump operate simultaneously under the hydraulic short-circuit operating condition; determining the turbine operating condition allocation coefficients based on the turbine operating conditions respectively. The hydraulic short-circuit operating condition distribution coefficient is determined according to the hydraulic short-circuit operating condition, and the pump operating condition distribution coefficient is determined according to the pump operating condition, wherein the turbine operating condition distribution coefficient includes the first turbine distribution coefficient and the first pump distribution coefficient, the pump operating condition distribution coefficient includes the third turbine distribution coefficient and the third pump distribution coefficient, and the hydraulic short-circuit operating condition distribution coefficient includes the second turbine distribution coefficient and the second pump distribution coefficient; the turbine guide vane opening value and the pump guide vane opening value are determined based on different turbine and pump distribution coefficients, or the turbine and pump guide vane opening values ​​are determined based on the deviation between the actual system frequency and the standard frequency that is greater than a preset threshold; the output power of the synchronous motor of the three-machine pumped storage unit is adjusted based on the pump guide vane opening value and the turbine guide vane opening value.

[0007] Optionally, different operating conditions of the three-machine pumped-storage unit are determined based on the reference power value, and different operating condition distribution coefficients are determined based on the different operating conditions, including: if the reference power value is greater than or equal to 0, the three-machine pumped-storage unit is determined to be in a turbine operating condition, and a corresponding turbine operating condition distribution coefficient is obtained; if the reference power value is equal to the rated power value of the water pump of the three-machine pumped-storage unit, the three-machine pumped-storage unit is determined to be in a water pump operating condition, and a corresponding water pump operating condition distribution coefficient is obtained; if the reference power value is less than 0 and is not equal to the rated power value of the water turbine of the three-machine pumped-storage unit, the three-machine pumped-storage unit is determined to be in a hydraulic short-circuit operating condition, and a corresponding hydraulic short-circuit operating condition distribution coefficient is obtained.

[0008] Optionally, the water turbine working condition distribution coefficient comprises a water pump first distribution coefficient and a water turbine first distribution coefficient, wherein the water pump first distribution coefficient is equal to 0, and the water turbine first distribution coefficient is equal to a ratio of the reference power value and a unit water pump rated power value; the water power short circuit working condition distribution coefficient comprises a water pump second distribution coefficient and a water turbine second distribution coefficient, wherein the water pump second distribution coefficient is equal to 1, and the water turbine second distribution coefficient is equal to a ratio of a sum of the reference power value and the water pump rated power value and a unit water turbine rated power; the water pump working condition distribution coefficient comprises a water pump third distribution coefficient and a water turbine third distribution coefficient, wherein the water pump third distribution coefficient is equal to 1, and the water turbine third distribution coefficient is equal to 0.

[0009] Optionally, before the corresponding determination of the water turbine guide vane first opening value and the water turbine guide vane second opening value based on the water turbine working condition distribution coefficient and the water power short circuit working condition distribution coefficient, the three-machine type pumped storage unit regulating method further comprises: obtaining a motor frequency deviation of the three-machine type pumped storage unit; judging whether the motor frequency deviation of the three-machine type pumped storage unit is outside a dead zone frequency range of the unit; if the motor frequency deviation is outside the dead zone frequency, inputting the motor frequency deviation into a first transfer function to obtain a water turbine guide vane opening value, wherein an expression of the first transfer function is:

[0010]

[0011] wherein g ref is a water turbine guide vane opening value; Δf is a unit frequency and power grid frequency deviation value; K0 is an analog amplifier and electro-hydraulic converter; K P is a proportional coefficient, K I is an integral coefficient, K D is a differential coefficient, R is a steady-state slip coefficient; T yB is an auxiliary servomotor time constant, T y is a main servomotor time constant, s is a complex variable representing a frequency in a Laplace transform domain; based on the water turbine guide vane third opening value, the output power of the water turbine is controlled, and based on the output power of the water turbine, the motor frequency deviation is controlled to be within the dead zone frequency range; if the motor frequency deviation is within the dead zone frequency range of the unit, no processing is performed.

[0012] Optionally, determining the turbine guide vane opening value based on the system frequency deviation and the reference power value greater than a preset threshold value includes: judging whether the system frequency deviation is greater than a preset threshold value; if it is greater than or equal to the preset threshold value, then under the turbine operating condition, determining the first opening value of the turbine guide vane based on the reference power value and the system frequency deviation, or under the hydraulic short circuit operating condition, determining the second opening value of the turbine guide vane based on the reference power value and the system frequency deviation.

[0013] Optionally, the first opening value of the turbine guide vane is determined based on the reference power value and the system frequency deviation under the turbine operating condition, or the second opening value of the turbine guide vane is determined based on the reference power value and the system frequency deviation under the hydraulic short-circuit operating condition, including: obtaining the reference power value and the system frequency deviation under the turbine operating condition, or the reference power value and the system frequency deviation under the hydraulic short-circuit operating condition; and obtaining the first opening value of the turbine guide vane or the second opening value of the turbine guide vane after processing the reference power value and the system frequency deviation through a regulation system.

[0014] Optionally, the three-machine pumped storage unit is provided with a regulator, the regulator including a two-stage hydraulic amplification component, wherein the first-stage hydraulic amplification component includes a pilot valve, an auxiliary servomotor, and a local feedback lever, and the second-stage hydraulic amplification component includes a main pressure regulating valve and a main servomotor. The regulation system includes a permanent slip module, a PID regulator, and the regulator connected in sequence; the step of obtaining the turbine guide vane opening value after processing the reference power value by the regulation system includes: obtaining an expression of a second transfer function, wherein the expression of the second transfer function includes:

[0015]

[0016] Where K0 is the conversion coefficient of the electro-hydraulic converter, K p is the proportionality coefficient, K I is the integral coefficient, K D is the differential coefficient, R is the permanent slip coefficient, T yB is the auxiliary relay time constant, Ty is the main relay time constant, P ref is the unit reference power value, s is a complex variable representing the frequency in the Laplace transform domain, g ref is the turbine guide vane opening value; based on the reference power value, the system frequency deviation and the transfer function, the turbine guide vane opening value is determined.

[0017] In order to solve the above problems, the present embodiment further provides a three-machine pumped storage unit regulation system, comprising: a first acquisition module for acquiring a reference power value of the power grid, wherein the reference power value is equal to the target power value of the power grid; a second acquisition module for acquiring a system frequency deviation, wherein the system frequency deviation is the difference between the unit motor frequency and the power grid frequency; a working condition determination module for determining different working conditions of the three-machine pumped storage unit based on the reference power value, and determining different working condition distribution coefficients based on the different working conditions, wherein the different working conditions include turbine working conditions, water pump working conditions and hydraulic short-circuit working conditions, wherein the turbine and the water pump work simultaneously under the hydraulic short-circuit working conditions; a water pump regulation module for determining the working condition distribution coefficient based on the water pump working condition distribution coefficient and the hydraulic short-circuit working condition distribution coefficient. a turbine regulating module, configured to respectively determine the first opening value of the turbine guide vane and the second opening value of the turbine guide vane based on the turbine operating condition distribution coefficient and the hydraulic short-circuit operating condition distribution coefficient, or to determine the first opening value of the turbine guide vane or the second opening value of the turbine guide vane based on the system frequency deviation and the reference power value that are greater than a preset threshold; an output module, configured to regulate the output power of the synchronous motor and the unit motor frequency of the three-machine pumped storage unit based on the separate third opening value of the pump guide vane and the first opening value of the turbine guide vane, or based on the common second opening value of the pump guide vane and the second opening value of the turbine guide vane, until the target power value and the preset grid frequency are reached.

[0018] In order to solve the above problems, this embodiment further provides a three-machine pumped storage unit regulating device, which has the three-machine pumped storage unit regulating system provided in the above embodiment.

[0019] In order to solve the above problems, this embodiment also provides a pumped storage power station, which has the three-machine pumped storage unit regulating equipment provided in the above embodiment.

[0020] The embodiment of the present application proposes a three-machine pumped storage unit regulation method and system, which obtains a reference power value of the power grid, the reference power value is equal to the target power value of the power grid; obtains a system frequency deviation, the system frequency deviation is the difference between the unit motor frequency and the power grid frequency; determines different operating conditions of the three-machine pumped storage unit based on the reference power value, and determines different operating condition distribution coefficients based on different operating conditions, wherein the different operating conditions include turbine operating conditions, pump operating conditions and hydraulic short-circuit operating conditions, the turbine working alone under the turbine operating conditions, the pump working alone under the pump operating conditions, and the turbine and pump working simultaneously under the hydraulic short-circuit operating conditions; determines three opening values ​​of the pump guide vane based on the pump operating condition distribution coefficient; determines the first opening value of the turbine guide vane and the first opening value of the turbine guide vane based on the turbine operating condition distribution coefficient and the hydraulic short-circuit operating condition distribution coefficient, respectively. The invention discloses a method for automatically adjusting the opening value of the turbine guide vane based on the system frequency deviation and the reference power value that are greater than a preset threshold value, or determining the first opening value of the turbine guide vane or the second opening value of the turbine guide vane based on the system frequency deviation and the reference power value that are greater than a preset threshold value; adjusting the output power of the synchronous motor of the three-machine pumped storage unit and the unit motor frequency based on the water pump guide vane opening value, the first opening value of the turbine guide vane or the second opening value of the turbine guide vane until the target power value and the preset grid frequency are reached, thereby realizing automatic adjustment of the turbine guide vane opening value with the reference power value or the frequency deviation as input. When the system frequency deviation or the reference power value changes, the change in the turbine guide vane opening value can change the mechanical output power of the unit motor and the system frequency deviation, thereby realizing automatic adjustment of the output or absorption power value of the unit with the reference power value or the frequency deviation as input, thereby meeting the load demand of the grid and maintaining a stable grid frequency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A flow chart of a method for regulating a three-machine pumped storage unit provided in an embodiment of the present application;

[0022] Figure 2 A structural diagram of a three-machine pumped storage unit provided in an embodiment of the present application;

[0023] Figure 3 A schematic diagram of the operating mode conversion of a three-machine pumped storage unit provided in an embodiment of the present application;

[0024] Figure 4 Schematic diagram of the turbine regulation system of the three-machine pumped storage unit provided in the embodiment of the present application;

[0025] Figure 5 Schematic diagram of the turbine regulating device module of the three-machine pumped storage unit provided in an embodiment of the present application.

[0026] The purpose, features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0027] It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0028] The three-machine pumped storage unit in this embodiment adds an additional pump system without changing the original structure of the traditional pumped storage unit. The system is coaxially connected to the turbine system. The hydraulic short-circuit mode (turbine and pump running at the same time) is the most important feature of the three-machine pumped storage technology. It can realize frequency regulation while pumping water. Figure 2 As shown, since the turbine and the water pump are coaxially connected, the speed of switching between the various operating conditions is also significantly reduced. In view of the characteristics of the separation of the turbine and the water pump of the three-machine pumped storage unit, this embodiment proposes a control method for controlling the turbine power and the water pump power by using power distribution. This method calculates the frequency deviation signal with a dead zone as a feedforward signal and uses the turbine and water pump opening as the control means. This method can ensure that the system switches quickly between the three operating modes and can ensure the power stability of the power generation system based on the power-frequency-opening relationship.

[0029] Specifically, the present application provides a three-machine pumped storage unit adjustment method, which can be executed by a processor of an adjustment device. Figure 1 The flow chart of the adjustment method of the three-machine pumped storage unit provided in the embodiment of the present application is as follows: Figure 1 , the regulators include:

[0030] S10, obtaining a reference power value of the power grid, where the reference power value is equal to a target power value of the power grid;

[0031] In power systems, the grid's reference power value typically refers to the grid's target power value, which is the ideal power level the grid aims to achieve under specific conditions. This value may be determined based on a variety of factors, including the grid's load demand, power supply capacity, and frequency and voltage stability requirements.

[0032] S20, obtaining a system frequency deviation, where the system frequency deviation is the difference between the unit motor frequency and the grid frequency;

[0033] Obtaining system frequency deviation typically refers to measuring the difference between the actual operating frequency of the power grid, i.e., the unit motor frequency, and the nominal frequency (e.g., 50 Hz), i.e., the grid frequency. This difference can reflect the stability and power supply quality of the power grid. Based on the definition of power system frequency deviation, the formula for calculating system frequency deviation Δf is:

[0034] Δf=f m -f N

[0035] Among them, f mis the actual frequency of the system, f N is the standard frequency of the system. For example, in China, the nominal frequency of the power grid is usually 50Hz. If the actual measured frequency is 49.98Hz, then the frequency deviation Δf is -0.02Hz.

[0036] In practical applications, the real-time frequency of the power grid can be obtained through various measurement devices and technologies. For example, the eCAP module and general timer of a DSP (digital signal processor) can be used to capture the rising edge of the input signal. The frequency of the input signal can be obtained by recording the trigger time of the two rising edges. This method has high precision and good real-time performance.

[0037] S30. Determine different operating conditions of the three-machine pumped storage unit based on the reference power value, and determine different operating condition allocation coefficients corresponding to the different operating conditions, wherein the different operating conditions include a turbine operating condition, a pump operating condition, and a hydraulic short-circuit operating condition. In the hydraulic short-circuit operating condition, the turbine and the pump operate simultaneously.

[0038] In the examples of this application, reference is made to Figure 3 , step S30 may include the following execution steps:

[0039] S31. If the reference power value is greater than or equal to 0, the three-machine pumped storage unit is determined to be in turbine operating mode, and a corresponding turbine operating mode allocation coefficient is obtained;

[0040] S32. If the reference power value is less than 0 and equal to the rated power value of the water pump of the three-machine pumped-storage unit, determine that the three-machine pumped-storage unit is in a water pump operating state, and obtain a corresponding water pump operating state allocation coefficient;

[0041] S33. If the reference power value is less than 0 and is not equal to the rated power value of the water pump of the three-machine pumped storage unit, the three-machine pumped storage unit is determined to be in a hydraulic short-circuit condition, and a corresponding hydraulic short-circuit condition distribution coefficient is obtained.

[0042] Specifically, the processor can first obtain a reference power value of the current three-machine pumped storage unit (hereinafter referred to as the unit). When the reference power value is greater than or equal to 0, the water pump is turned off, and the reference power value is used as the operating power of the turbine. The first opening value of the turbine is adjusted in combination with the set distribution coefficient.

[0043] When the reference power value is less than 0 and is not equal to the rated power value of the water pump of the three-machine pumped storage unit, the water pump is turned on, and the operating power of the water pump and the operating power of the turbine unit are determined respectively, and the second opening value of the turbine is adjusted in combination with the set distribution coefficient.

[0044] When adjusting the opening value of the turbine, it is also necessary to obtain the grid frequency fluctuation and determine whether the obtained grid frequency fluctuation is within the tolerable range of the unit system. If it is within the tolerable range, the water pump and turbine will be activated.

[0045] When it is outside the tolerable range, the reference power value and the deviation between the unit frequency and the grid frequency are used to determine the turbine guide vane opening value, and the turbine is regulated and controlled using the obtained turbine guide vane opening value.

[0046] In this embodiment, continue to refer to Figure 3 The turbine operating condition, pump operating condition and hydraulic short circuit operating condition correspond to three working modes respectively. Among them, the turbine operating condition distribution coefficient includes: the first distribution coefficient of the pump and the first distribution coefficient of the turbine. Among them, the first distribution coefficient of the pump is equal to 0, and the first distribution coefficient of the turbine is equal to the ratio of the reference power value to the rated power value of the turbine unit, that is, K d_p =0, Where K d_t is the distribution coefficient of the turbine, K d_p is the distribution coefficient of the pump, P f_t is the rated power of the turbine unit, P ref The processor can adjust the turbine opening according to the first distribution coefficient of the turbine, thereby eliminating the deviation between the reference power and the unit motor frequency.

[0047] Continue to refer Figure 3 The pump operating condition distribution coefficient includes: the third distribution coefficient of the pump and the third distribution coefficient of the turbine, wherein the third distribution coefficient of the pump is equal to 1 and the third distribution coefficient of the turbine is equal to 0, that is, K d_p =1,K d_t =0.

[0048] Continue to refer Figure 3 The hydraulic short-circuit distribution coefficient includes the second distribution coefficient of the water pump and the second distribution coefficient of the turbine. The second distribution coefficient of the water pump is equal to 1, and the second distribution coefficient of the turbine is equal to the ratio of the sum of the reference power value and the rated power value of the water pump of the unit to the rated power of the unit, that is,

[0049] , where P f_p It is the rated power of the unit's pump. The turbine opening is adjusted according to the turbine's third distribution coefficient to eliminate the deviation between the reference power and the unit's motor frequency.

[0050] The coefficients are used to control the start and stop of the water pump and the water turbine and the specific opening value, so that different operation needs in different operation modes can be met. In order to control the mechanical coupling between the water turbine and the water pump and the shaft, the controller realizes the combined operation of the water turbine and the water pump (separately or together), and can generate a positive or negative mechanical power signal to the synchronous motor in a specific case.

[0051] S40, determining the water pump guide vane third opening value and the water pump guide vane second opening value respectively based on the water pump working condition distribution coefficient and the hydraulic short circuit working condition distribution coefficient;

[0052] It should be noted that the water pump working condition distribution coefficient, the water turbine working condition distribution coefficient or the hydraulic short circuit working condition distribution coefficient is between 0 and 1.

[0053] Specifically, after the water pump working condition distribution coefficient is determined, the water pump guide vane first opening value can be determined, or after the hydraulic short circuit working condition distribution coefficient is determined, the water pump guide vane second opening value can be determined. In the water pump operation, the adjustment of the guide vane opening is an important means to realize the performance adjustment of the water pump. By changing the guide vane opening, the flow, head and power parameters of the water pump can be changed to adapt to different working requirements.

[0054] S50, determining the water turbine guide vane first opening value and the water turbine guide vane second opening value respectively based on the water turbine working condition distribution coefficient and the hydraulic short circuit working condition distribution coefficient, or determining the water turbine guide vane first opening value or the water turbine guide vane second opening value based on the system frequency deviation greater than the preset threshold and the reference power value;

[0055] In the embodiment of the present application, before step S50, the three-machine type pumped storage unit adjusting method can further include the following execution steps:

[0056] S61, obtaining the motor frequency deviation of the three-machine type pumped storage unit;

[0057] S62, judging whether the motor frequency deviation of the three-machine type pumped storage unit is outside the dead zone frequency range of the unit;

[0058] S63, if the system frequency deviation is outside the dead zone frequency, inputting the motor frequency deviation into the first transfer function to obtain the water turbine guide vane opening value, wherein the expression of the first transfer function is:

[0059]

[0060] In the formula, g ref is the water turbine guide vane first opening value, Δf is the system frequency deviation, K0 is an analog amplifier and an electro-hydraulic converter; K P is a proportional coefficient, K I is an integral coefficient, K Dis the differential coefficient, R is the permanent state slip coefficient, T yB is the auxiliary servomotor time constant, T y is the main servomotor time constant, s is a complex variable representing frequency in the Laplace transform domain;

[0061] S64, controlling the output power of the hydraulic turbine based on the guide vane opening value of the hydraulic turbine, and controlling the frequency deviation of the motor to be within the dead zone frequency range based on the output power of the hydraulic turbine;

[0062] S65, if the frequency deviation of the motor is within the dead zone frequency range of the unit, no processing is performed.

[0063] Specifically, the processor can send the deviation signal to the regulator when the frequency deviation of the unit is outside the dead zone range by executing steps S61-S65, and send the processed signal to the guide valve, the main pressure distribution valve and the servomotor of the hydraulic turbine after PID operation, and finally obtain the third opening value of the guide vane of the hydraulic turbine. The processor adjusts the hydraulic turbine using the third opening value of the guide vane of the hydraulic turbine, thereby eliminating the deviation. The processor sets a dead zone for the frequency deviation, and the signal is not sent to the regulator within the dead zone range, so as to avoid affecting the stability of the unit due to frequent operation of the unit.

[0064] In the embodiments of the present application, step S50 can include the following execution steps:

[0065] S51, determining whether the system frequency deviation is greater than a preset threshold value;

[0066] S52, if greater than or equal to the preset threshold value, determining the first opening value of the guide vane of the hydraulic turbine based on the reference power value and the system frequency deviation under the hydraulic turbine operating condition, or determining the second opening value of the guide vane of the hydraulic turbine based on the reference power value and the system frequency deviation under the hydraulic short circuit operating condition.

[0067] In the embodiments of the present application, step S52 can include the following execution steps:

[0068] S521, obtaining the reference power value and the system frequency deviation under the hydraulic turbine operating condition, or the reference power value and the system frequency deviation under the hydraulic short circuit operating condition;

[0069] S522, obtaining the first opening value of the guide vane of the hydraulic turbine or the second opening value of the guide vane of the hydraulic turbine after processing the reference power value by the regulating system.

[0070] In the embodiments of the present application, the three-machine type pumped storage unit regulator includes a two-stage hydraulic amplification assembly, wherein the first-stage hydraulic amplification assembly includes a guide valve, an auxiliary servomotor and a local feedback lever, the second-stage hydraulic amplification assembly includes a main pressure distribution valve and a main servomotor, and the regulating system includes a permanent state slip module, a PID regulator and a regulator connected in sequence.

[0071] In the examples of this application, reference is made to Figure 4 , step S522 may include the following execution steps:

[0072] S5221. Obtain an expression of a second transfer function, wherein the expression of the second transfer function includes:

[0073]

[0074] Where K0 is the conversion coefficient of the electro-hydraulic converter, K p is the proportionality coefficient, K I is the integral coefficient, K D is the differential coefficient, R is the permanent slip coefficient, T yB is the auxiliary relay time constant, T y is the main relay time constant, s is a complex variable representing the frequency in the Laplace transform domain, g ref is the turbine guide vane opening value, p ref is the reference power value of the unit;

[0075] The expression of the second transfer function, that is, the transfer function acquisition process of the regulating system includes: obtaining the closed-loop transfer function of the first-stage hydraulic amplification component of the regulator:

[0076]

[0077] Where, with the pilot valve represented as 1 and the local feedback lever represented as 1, The transfer function of the auxiliary relay is represented by Among them, Y B represents the relative displacement of the auxiliary servomotor, S B Indicates the relative displacement of the pilot valve opening ΔY B Indicates the displacement deviation of the auxiliary relay, ΔS B Indicates the displacement deviation of the pilot valve, Y Bmax Indicates the maximum displacement of the auxiliary force device, S Bmax Indicates the maximum opening of the pilot valve; Indicates the reaction time constant of the auxiliary relay A B 、V B 、W B represent the piston area of ​​the auxiliary servomotor, the window flow rate and the window width of the pilot valve, respectively.

[0078] After obtaining the auxiliary relay transfer function, the auxiliary relay time constant can be determined using the auxiliary relay transfer function.

[0079] Obtain the transfer function of the second-stage hydraulic amplification component of the regulator and determine the main relay time constant T based on the transfer function y ;

[0080] The transfer function of the second-stage hydraulic amplification component is:

[0081]

[0082] Where Y represents the relative displacement of the main relay Y(s) represents the Laplace transform of Y, S A Indicates the relative displacement of the main pressure regulating valve opening S A (s) represents the Laplace transform of S, T y represents the main relay reaction time constant, Y max Indicates the maximum displacement of the main relay, S Amax represents the maximum opening of the main pressure regulating valve, A, V, and W represent the piston area of ​​the main relay, the window flow rate, and the window width of the main pressure regulating valve, respectively.

[0083] Obtain the permanent slip coefficient of the permanent slip module, as well as the proportional coefficient, integral coefficient and differential coefficient of the PID regulator;

[0084] A second transfer function is determined based on the permanent slip coefficient, the proportional coefficient, the integral coefficient, the differential coefficient, the auxiliary servomotor time constant, and the main servomotor time constant.

[0085] S5222. Determine a first opening value of the turbine guide vanes or a second opening value of the turbine guide vanes based on the reference power value, the system frequency deviation, and the transfer function.

[0086] Specifically, the Laplace transfer function of the regulation system is a mathematical model that describes the dynamic behavior of the turbine. It can be used to analyze system characteristics such as stability and frequency response. In control system design, the second transfer function can be used to design a controller, such as a PID controller, to achieve precise control of the turbine's guide vane opening. This controller dynamically adjusts the guide vane opening based on a reference power value and system frequency deviation.

[0087] S60. Adjust the synchronous motor output power and unit motor frequency of the three-machine pumped storage unit based on the individual first opening value of the pump guide vane and the first opening value of the turbine guide vane, or based on the common second opening value of the pump guide vane and the second opening value of the turbine guide vane, until the target power value and the preset grid frequency are reached.

[0088] In summary, the present embodiment provides a method for regulating a three-machine pumped storage unit, which obtains a reference power value of the power grid, where the reference power value is equal to a target power value of the power grid; obtains a system frequency deviation, where the system frequency deviation is the difference between the unit motor frequency and the power grid frequency; determines different operating conditions of the three-machine pumped storage unit based on the reference power value, and determines different operating condition distribution coefficients based on the different operating conditions, wherein the different operating conditions include turbine operating conditions, pump operating conditions, and hydraulic short-circuit operating conditions, and under the hydraulic short-circuit operating conditions, the turbine and the pump work simultaneously; determines the pump guide vane opening value based on the pump operating condition distribution coefficient; determines the first opening value of the turbine guide vane and the first opening value of the turbine guide vane based on the turbine operating condition distribution coefficient and the hydraulic short-circuit operating condition distribution coefficient, respectively. The invention discloses a method for automatically adjusting the opening value of the turbine guide vane based on the first opening value of the turbine guide vane and the second opening value of the turbine guide vane, or determining the first opening value of the turbine guide vane or the second opening value of the turbine guide vane based on the system frequency deviation and the reference power value that are greater than a preset threshold value; adjusting the output power of the synchronous motor of the three-machine pumped storage unit and the unit motor frequency based on the water pump guide vane opening value, the first opening value of the turbine guide vane or the second opening value of the turbine guide vane until the target power value and the preset grid frequency are reached, realizing automatic adjustment of the turbine guide vane opening value with the reference power value or the frequency deviation as input; when the system frequency deviation or the reference power value changes, the change in the turbine guide vane opening value can change the mechanical output power of the unit motor and the system frequency deviation, which helps to maintain a stable grid frequency and achieve rapid response to grid instructions.

[0089] Based on the above embodiment, the present application also provides a three-machine pumped storage unit regulating system 100, referring to Figure 5 The regulation system 100 may include a first acquisition module 101, a second acquisition module 102, a first coefficient determination module 103, a second coefficient determination module 104, an opening value determination module 105, and an output module 106. The first acquisition module 101 is used to obtain a reference power value of the power grid, where the reference power value is equal to a target power value of the power grid.

[0090] The second acquisition module 102 is used to obtain the system frequency deviation, where the system frequency deviation is the deviation between the actual system frequency and the standard frequency;

[0091] The first coefficient determination module 103 is configured to determine different operating conditions of the three-machine pumped storage unit based on the reference power value, and determine corresponding operating condition allocation coefficients based on the different operating conditions, wherein the different operating conditions include a turbine operating condition, a hydraulic short-circuit operating condition, and a water pump operating condition. In the turbine operating condition, the turbine operates alone; in the water pump operating condition, the pump operates alone; and in the hydraulic short-circuit operating condition, the turbine and the pump operate simultaneously.

[0092] The second coefficient determination module 104 is used to determine a turbine operating condition distribution coefficient, a hydraulic short-circuit operating condition distribution coefficient, and a pump operating condition distribution coefficient based on the turbine operating condition, respectively, wherein the turbine operating condition distribution coefficient includes a first turbine distribution coefficient and a first pump distribution coefficient, the pump operating condition distribution coefficient includes a third turbine distribution coefficient and a third pump distribution coefficient, and the hydraulic short-circuit operating condition distribution coefficient includes a second turbine distribution coefficient and a second pump distribution coefficient;

[0093] The opening value determination module 105 is used to determine the turbine guide vane opening value and the pump guide vane opening value based on different turbine and pump distribution coefficients, or to determine the turbine and pump guide vane opening value based on the deviation between the actual system frequency and the standard frequency that is greater than a preset threshold;

[0094] The output module 106 is used to adjust the output power of the synchronous motor of the three-machine pumped storage unit based on the water pump guide vane opening value and the turbine guide vane opening value.

[0095] On the basis of the above embodiments, the present application also provides a three-machine pumped storage unit regulating device, which has the three-machine pumped storage unit regulating system provided by the above embodiments.

[0096] On the basis of the above embodiments, the present application also provides a pumped storage power station having the three-machine pumped storage unit regulating equipment provided in the above embodiments.

[0097] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for regulating a three-machine pumped storage unit, characterized in that: include: Obtaining a reference power value of the power grid, where the reference power value is equal to a target power value of the power grid; Obtaining a system frequency deviation, where the system frequency deviation is a deviation between an actual system frequency and a standard frequency; Determining different operating conditions of the three-machine pumped storage unit based on the reference power value, and determining different operating condition allocation coefficients corresponding to the different operating conditions, wherein the different operating conditions include a turbine operating condition, a hydraulic short-circuit operating condition, and a water pump operating condition, wherein the turbine operates alone in the turbine operating condition, the pump operates alone in the water pump operating condition, and the turbine and the pump operate simultaneously in the hydraulic short-circuit operating condition; Determining a turbine operating condition distribution coefficient, a hydraulic short-circuit operating condition distribution coefficient, and a pump operating condition distribution coefficient based on the turbine operating condition, respectively, wherein the turbine operating condition distribution coefficient includes a first turbine distribution coefficient and a first pump distribution coefficient, the pump operating condition distribution coefficient includes a third turbine distribution coefficient and a third pump distribution coefficient, and the hydraulic short-circuit operating condition distribution coefficient includes a second turbine distribution coefficient and a second pump distribution coefficient; Determining turbine guide vane opening values ​​and pump guide vane opening values ​​based on different turbine and pump distribution coefficients, or determining turbine and pump guide vane opening values ​​based on a deviation between an actual system frequency and a standard frequency that is greater than a preset threshold; The output power of the synchronous motor of the three-machine pumped storage unit is adjusted based on the opening value of the water pump guide vane and the opening value of the turbine guide vane.

2. A three-machine pumped storage unit adjustment method according to claim 1, characterized in that: Determining different operating conditions of the three-machine pumped storage unit based on the reference power value, and determining different operating condition allocation coefficients corresponding to the different operating conditions, includes: If the reference power value is greater than or equal to 0, determining that the three-machine pumped storage unit is in a turbine operating state, obtaining a turbine operating state distribution coefficient, and determining a first turbine guide vane opening value and a first pump guide vane opening value based on the turbine operating state distribution coefficient; If the reference power value is less than 0 and the reference power value is not equal to the rated power value of the water pump of the three-machine pumped storage unit, the three-machine pumped storage unit is determined to be in a hydraulic short-circuit condition, a corresponding hydraulic short-circuit condition distribution coefficient is obtained, and the second opening value of the turbine guide vane and the second opening value of the water pump guide vane are determined based on the hydraulic short-circuit condition distribution coefficient. If the reference power value is less than 0 and the reference power value is equal to the rated power value of the water pump of the three-machine pumped-storage unit, the three-machine pumped-storage unit is determined to be in water pump operating condition, and the corresponding water pump operating condition distribution coefficient is obtained, and the third opening value of the turbine guide vane and the third opening value of the water pump guide vane are determined based on the water pump operating condition distribution coefficient.

3. The method for regulating a three-machine pumped storage unit according to claim 1, wherein: The turbine operating condition distribution coefficient includes: a first distribution coefficient for the water pump and a first distribution coefficient for the water turbine, wherein the first distribution coefficient for the water pump is equal to 0, and the first distribution coefficient for the water turbine is equal to a ratio of the reference power value to the rated power value of the water turbine of the unit; The hydraulic short-circuit operating condition distribution coefficient includes: a second water pump distribution coefficient and a second water turbine distribution coefficient, wherein the second water pump distribution coefficient is equal to 1, and the second water turbine distribution coefficient is equal to the ratio of the sum of the reference power value and the rated power value of the unit water pump to the rated power of the unit water turbine; The water pump operating condition distribution coefficient includes: a second distribution coefficient for the water pump and a second distribution coefficient for the water turbine, wherein the second distribution coefficient for the water pump is equal to 1, and the second distribution coefficient for the water turbine is equal to 0.

4. A three-machine pumped storage unit adjustment method according to claim 2, characterized in that: Before respectively determining the first turbine distribution coefficient and the second turbine opening value based on the turbine operating condition distribution coefficient and the hydraulic short-circuit operating condition distribution coefficient, the three-machine pumped storage unit adjustment method further includes: Obtaining a motor frequency deviation of the three-machine pumped storage unit; determining whether a motor frequency deviation of the three-machine pumped storage unit is outside a dead band frequency range of the unit; If the motor frequency deviation is outside the dead band frequency, the motor frequency deviation is input into the first transfer function to obtain the turbine guide vane opening value, wherein the expression of the first transfer function is: Where g ref is the turbine guide vane opening value; Δf is the deviation between the unit frequency and the grid frequency; K0 is the analog amplifier and electro-hydraulic converter; K P is the proportionality coefficient, K I is the integral coefficient, K D is the differential coefficient, R is the permanent slip coefficient; T yB is the auxiliary relay time constant, T y is the main relay time constant, s is a complex variable representing the frequency in the Laplace transform domain; controlling the output power of the turbine based on the third opening value of the turbine guide vanes, and controlling the motor frequency deviation to be within the dead band frequency range based on the output power of the turbine; If the motor frequency deviation falls within the dead band frequency range of the unit, no processing is performed.

5. The method for regulating a three-machine pumped storage unit according to claim 1, wherein: The determining the first opening value of the turbine guide vane or the second opening value of the turbine guide vane based on the system frequency deviation greater than a preset threshold and the reference power value includes: Determining whether the system frequency deviation is greater than a preset threshold; If it is greater than or equal to the preset threshold, then under the turbine operating condition, the first opening value of the turbine guide vane is determined based on the reference power value and the system frequency deviation, or under the hydraulic short circuit operating condition, the second opening value of the turbine guide vane is determined based on the reference power value and the system frequency deviation.

6. A three-machine pumped storage unit adjustment method according to claim 5, characterized in that: The determining of the first opening value of the turbine guide vanes based on the reference power value and the system frequency deviation under the turbine operating condition, or the determining of the second opening value of the turbine guide vanes based on the reference power value and the system frequency deviation under the hydraulic short-circuit operating condition, comprises: Obtaining the reference power value and the system frequency deviation under the turbine operating condition, or the reference power value and the system frequency deviation under the hydraulic short-circuit operating condition; After the reference power value and the system frequency deviation are processed by a regulating system, a first opening value of the turbine guide vane or a second opening value of the turbine guide vane is obtained.

7. A three-machine pumped storage unit adjustment method according to claim 6, characterized in that: The three-machine pumped storage unit has a regulator, which includes a two-stage hydraulic amplification component, wherein the first-stage hydraulic amplification component includes a pilot valve, an auxiliary relay and a local feedback lever, and the second-stage hydraulic amplification component includes a main pressure regulating valve and a main relay. The regulation system includes a permanent slip module, a PID regulator and the regulator connected in sequence; The step of obtaining the turbine guide vane opening value by processing the reference power value through a regulating system includes: Obtain an expression for a second transfer function, wherein the expression for the second transfer function includes: Where K0 is the conversion coefficient of the electro-hydraulic converter, K p is the proportionality coefficient, K I is the integral coefficient, K D is the differential coefficient, R is the permanent slip coefficient, T yB is the auxiliary relay time constant, Ty is the main relay time constant, P ref is the unit reference power value, s is a complex variable representing the frequency in the Laplace transform domain, g ref is the turbine guide vane opening value; The turbine guide vane opening value is determined based on the reference power value, the system frequency deviation, and the transfer function.

8. A three-machine pumped storage unit regulating system, characterized in that: include: A first acquisition module is configured to acquire a reference power value of the power grid, where the reference power value is equal to a target power value of the power grid; A second acquisition module is used to obtain a system frequency deviation, where the system frequency deviation is the deviation between the actual system frequency and the standard frequency; a first coefficient determination module, configured to determine different operating conditions of the three-machine pumped storage unit based on the reference power value, and determine corresponding operating condition allocation coefficients based on the different operating conditions, wherein the different operating conditions include a turbine operating condition, a hydraulic short-circuit operating condition, and a water pump operating condition; the turbine operating condition is the turbine operating alone; the water pump operating condition is the water pump operating alone; and the hydraulic short-circuit operating condition is the turbine and the water pump operating simultaneously; a second coefficient determination module, configured to determine a turbine operating condition distribution coefficient, a hydraulic short-circuit operating condition distribution coefficient, and a pump operating condition distribution coefficient based on the turbine operating condition, respectively, wherein the turbine operating condition distribution coefficient includes a first turbine distribution coefficient and a first pump distribution coefficient, the pump operating condition distribution coefficient includes a third turbine distribution coefficient and a third pump distribution coefficient, and the hydraulic short-circuit operating condition distribution coefficient includes a second turbine distribution coefficient and a second pump distribution coefficient; an opening value determination module, configured to determine the turbine guide vane opening value and the pump guide vane opening value based on different turbine and pump distribution coefficients, or to determine the turbine and pump guide vane opening value based on a deviation between the actual system frequency and the standard frequency that is greater than a preset threshold; The output module is used to adjust the output power of the synchronous motor of the three-machine pumped storage unit based on the water pump guide vane opening value and the turbine guide vane opening value.

9. A three-machine pumped storage unit regulating device, characterized in that: A three-machine pumped storage unit regulating system is provided as claimed in claim 8.

10. A pumped storage power station, characterized in that: A three-machine pumped storage unit regulating device is provided as claimed in claim 9.

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