Frequency regulation control optimization method, system, and storage medium based on wind-energy storage-energy storage integrated system

Abstract

This application relates to the field of power system control technology, and more particularly to a frequency regulation control optimization method, system, and storage medium based on a wind-storage-energy storage combined system. On one hand, a rotor kinetic energy strategy is used to control the wind turbine system for frequency regulation to provide frequency support, while the energy storage battery compensates for the power reduction caused by the water hammer effect in pumped hydro storage and supports the recovery of wind turbine speed, realizing the complementary advantages of wind and energy storage resources. On the other hand, the coordinated power compensation of the pumped hydro storage system and the energy storage system overcomes the dead zone difference between the actual output of the thermal power system and the automatic generation control commands. The aim is to solve the problem of how to improve the frequency stability of the power system.

Description

Technical Field

[0001] This application relates to the field of power system control technology, and in particular to a frequency regulation control optimization method, system and storage medium based on a wind-storage-energy storage combined system. Background Technology

[0002] With the transformation of the global energy structure, wind energy, as one of the most promising new energy sources, is receiving increasing attention for its development and utilization. However, wind power output currently exhibits strong randomness and volatility, posing a significant challenge to the frequency stability of the power system. In related technical solutions, research has already introduced pumped hydro storage and energy storage batteries as energy storage components for wind power, which can effectively improve the absorption rate of wind power in new power systems.

[0003] However, current wind farm frequency regulation control strategies mostly focus on the utilization of single resources, lacking synergistic optimization of multiple resources such as wind, energy storage, and energy storage. Traditional wind farm modeling methods struggle to improve simulation efficiency while maintaining accuracy, limiting the frequency regulation performance evaluation of large-scale wind farms. Furthermore, there is room for optimization in the model construction and control strategy design of pumped storage units and energy storage batteries when they participate in frequency regulation.

[0004] In view of this, this application proposes a frequency regulation control optimization method based on a wind-storage-energy storage combined system. By combining the frequency regulation of wind, energy storage and energy storage systems, the method achieves synergistic optimization of multiple frequency regulation resources and improves the frequency stability of the power system. Summary of the Invention

[0005] The main objective of this application is to provide a frequency regulation control optimization method based on a wind-storage-energy storage combined system, which aims to solve the problem of how to improve the frequency stability of the power system.

[0006] To achieve the above objectives, this application provides a frequency regulation control optimization method based on a wind-storage-energy storage combined system, the method comprising:

[0007] S10, when a water hammer effect is detected in the pumped storage system, the rotor kinetic energy strategy is used to control the wind turbine system to adjust the frequency, and when the output power of the wind turbine system decreases, the energy storage system is controlled to perform power compensation.

[0008] S20, determine the dead zone difference between the actual output of the thermal power system and the automatic power generation control command, and control the pumped storage system and the energy storage system to coordinate and compensate for the power to meet the dead zone difference.

[0009] Optionally, in step S10, controlling the wind turbine system for frequency regulation using a rotor kinetic energy strategy includes the following steps:

[0010] S11, Obtain the frequency change rate and frequency deviation of the wind turbine system;

[0011] S12, determine the target frequency regulation power increment of the wind turbine system based on the frequency change rate and the frequency deviation, wherein the calculation expression for the target frequency regulation power is:

[0012]

[0013] In the formula, Δf represents the target frequency regulation power increment for the primary frequency regulation of the wind turbine; Δf represents the system frequency deviation. The rate of change of frequency; For virtual inertia coefficients, This is the droop coefficient;

[0014] S13, control the wind turbine system to perform frequency regulation based on the target frequency regulation power increment.

[0015] Optionally, both the virtual inertia coefficient and the droop coefficient are adjusted with the rate of change of frequency;

[0016] Among them, the adjusted virtual inertial parameters Satisfy the following expression:

[0017]

[0018] In the formula, the time constant T is proportional to the output power and frequency modulation exit time under virtual inertial control, and s is the Laplace operator;

[0019] Among them, the adjusted droop parameter K 2,1 Satisfy the following expression:

[0020]

[0021] In the formula, t is the current simulation time, t re k is the time for the wind turbine to exit frequency regulation. c Parameters used to control the rate of change.

[0022] Optionally, in step S10, the step of controlling the energy storage system to perform power compensation includes:

[0023] S14, Calculate the current water hammer output compensation power required by the energy storage system. :

[0024]

[0025] In the formula, TB is the constant of the energy storage converter; , This is a self-adjusting energy storage rapid compensation coefficient based on operating status, used to accurately offset the reverse adjustment of pumped storage power; This represents the dynamics of a first-order inertial energy storage converter.

[0026] S15, Calculate the required compensation power of the energy storage system. :

[0027]

[0028] In the formula, For energy storage additional coefficient, The rated power of the fan system. This represents the real-time power of the wind turbine system. This refers to the rated power of the energy storage system.

[0029] in:

[0030]

[0031] In the formula; Let be the slope of the Logistic curve. The center point of the Logistic curve, This represents the maximum value of the energy storage additional coefficient;

[0032] S16, the current water hammer output compensation power With the energy storage support power The sum of these values ​​serves as the total power compensation power of the energy storage system. :

[0033]

[0034] S17, control the energy storage system based on the total power compensation power. Perform power compensation.

[0035] Optionally, the energy storage fast compensation coefficient satisfy:

[0036]

[0037] In the formula, This represents the energy storage baseline compensation coefficient, used to adjust the compensation intensity for water hammer effect; Indicates the angular velocity of the fan rotor;

[0038] If the frequency of the doubly-fed asynchronous wind turbine after it is removed from frequency regulation still does not meet the frequency requirements, then a new energy storage droop compensation coefficient K is needed. B2,1 satisfy;

[0039]

[0040] The energy storage support power satisfy:

[0041]

[0042] in:

[0043]

[0044] .

[0045] Optionally, S20 specifically includes:

[0046] S21, determine the current stage of the thermal power system, wherein the current stage includes one of the response stage, ramp-up stage, and stabilization stage;

[0047] S22, Determine the target compensation strategy for the pumped storage system and the energy storage system based on the current stage of the thermal power system;

[0048] S23, based on the same-direction dead zone difference, control the pumped storage system and the energy storage system to collaboratively compensate for the power that satisfies the same-direction dead zone difference according to the target compensation strategy.

[0049] Optionally, the target compensation strategy includes:

[0050] S221, when the thermal power system is in the response phase, control the pumped storage system and the energy storage system to coordinate compensation to meet the first power requirement of the same-direction dead zone difference. :

[0051]

[0052] In the formula, ΔP pump (t) represents the power deviation of the pumped storage unit at time t; ΔP bcss (t) represents the power deviation of the energy storage battery at time t;

[0053] S222, when the thermal power system is in the ramp-up phase, based on the available frequency regulation capacity of the pumped storage system and the energy storage system, determine the respective power allocation ratios of the pumped storage system and the energy storage system, and control the pumped storage system and the energy storage system to compensate for the second power that satisfies the same-direction dead zone difference while meeting their respective power allocation ratios. :

[0054]

[0055]

[0056] In the formula, α, All of these are power allocation ratios. Let t be the power deviation of the pumped storage system at time t. Let be the power deviation of the energy storage system at time t;

[0057] The calculation expression for the power allocation ratio is as follows:

[0058]

[0059] In the formula, Let t be the available frequency regulation capacity of the pumped storage system at time t; This represents the remaining frequency regulation capacity of the energy storage system.

[0060] S223, when the thermal power system is in a stable phase, optimize the processing allocation of the pumped storage system and the energy storage system with the goal of minimizing the steady-state frequency deviation.

[0061] Optionally, in step S223, the step of optimizing the processing allocation of the pumped hydro storage system and the energy storage system with the objective of minimizing the steady-state frequency deviation includes:

[0062] S2231, Determine the steady-state frequency deviation between the pumped hydro storage system and the energy storage system. :

[0063]

[0064] In the formula, Δf1(t) and Δf2(t) are the steady-state frequency deviations of the dead zone and the linear response zone at time t, respectively;

[0065] S2232, according to the state frequency deviation Determine the smooth output of the energy storage system :

[0066]

[0067] In the formula, K droop This refers to the energy storage droop factor.

[0068] S2233, according to the smooth output force Calculate the supporting output of the pumped storage system. :

[0069]

[0070] In the formula, Frequency deviation coefficient; Generator droop coefficient; This refers to the change in system load.

[0071] S2234, Control the energy storage system based on the smooth output Perform power compensation and control the pumped storage system based on the support output. Perform power compensation.

[0072] In addition, to achieve the above objectives, this application also provides a computer system, the computer system comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, it implements the steps of the frequency regulation control optimization method based on the wind-storage-energy storage combined system as described in any of the preceding claims.

[0073] In addition, to achieve the above objectives, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the frequency regulation control optimization method based on the wind-storage-energy storage combined system as described in any of the preceding claims.

[0074] This application has at least the following beneficial effects:

[0075] 1. The wind turbine system is controlled by a rotor kinetic energy strategy to provide frequency support through frequency regulation. The energy storage battery compensates for the power reduction caused by the water hammer effect in pumped hydro storage and supports the recovery of wind turbine speed, thus realizing the complementary advantages of wind and energy storage resources.

[0076] 2. The problem of dead zone difference between the actual output of thermal power system and automatic generation control command can be overcome by using the coordinated power compensation of pumped storage system and energy storage system;

[0077] 3. By coordinating wind-storage-energy storage frequency regulation, the frequency regulation burden on thermal power systems is reduced; Attached Figure Description

[0078] Figure 1 This is a flowchart illustrating the first embodiment of the frequency regulation control optimization method based on a wind-storage-energy storage combined system involved in this application.

[0079] Figure 2 This is a schematic diagram of the water hammer effect of a water turbine involved in an embodiment of this application;

[0080] Figure 3 This is a schematic diagram of a dual-mode frequency modulation model of a wind turbine involved in an embodiment of this application;

[0081] Figure 4 This is a schematic diagram of the structure of the water pump turbine simulation model involved in the embodiments of this application;

[0082] Figure 5 This is an equivalent circuit diagram of a lead-carbon battery involved in an embodiment of this application;

[0083] Figure 6 This is a circuit diagram of a lead-carbon battery control system according to an embodiment of this application.

[0084] Figure 7 This is a simulation diagram of the primary frequency regulation of the equivalent wind turbine unit and energy storage involved in the embodiments of this application;

[0085] Figure 8 This is a wind speed scene at a certain moment and an equivalent wind speed distribution diagram of each air group involved in the embodiments of this application;

[0086] Figure 9 The following are system frequency response diagrams for different control strategies involved in the embodiments of this application;

[0087] Figure 10 This is a diagram showing the output power of each generator group involved in the embodiments of this application;

[0088] Figure 11 This is a diagram showing the output power of the energy storage involved in the embodiments of this application;

[0089] Figure 12 This is a diagram of the three-region frequency control model of the combined system involved in the embodiments of this application;

[0090] Figure 13 This is a comparison diagram of secondary frequency modulation in three different scenarios according to the embodiments of this application;

[0091] Figure 14 This is a comparison diagram of transient and steady-state frequency offsets under three different scenarios involved in the embodiments of this application;

[0092] Figure 15 This is a diagram showing the output of the pumped storage and thermal power systems in region i, as described in the embodiments of this application.

[0093] Figure 16 This is a diagram showing the AGC output of the i-region energy storage system involved in the embodiments of this application.

[0094] Figure 17 This is a schematic diagram of the hardware operating environment of the computer system involved in the embodiments of this application;

[0095] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0096] To better understand the above technical solutions, exemplary embodiments of this disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0097] First Embodiment

[0098] Reference Figure 1 This embodiment provides a frequency regulation control optimization method based on a wind-storage-energy storage combined system. This method is applied to a hybrid power generation system including a wind turbine system, a pumped storage system, an energy storage system, and a thermal power system. Specifically, it includes the following steps:

[0099] S10, when a water hammer effect is detected in the pumped storage system, the rotor kinetic energy strategy is used to control the wind turbine system to adjust the frequency, and when the output power of the wind turbine system decreases, the energy storage system is controlled to perform power compensation.

[0100] In this embodiment, when the water hammer effect occurs, refer to Figure 2 The diagram illustrates the water hammer effect in a water turbine. This effect is primarily caused by the inertia of the water flow in the pipes, manifesting as a lag between changes in the water flow within the turbine and changes in the opening of its guide vanes. When the guide vanes open, although an increase in flow is expected, the instantaneous drop in pipe pressure causes a brief decrease in output power rather than an immediate increase, resulting in a reverse regulation—the water hammer phenomenon. This effect is more pronounced in pump-turbine models containing a water intake system, where the pipe length and structural characteristics of the water intake system exacerbate the water flow inertia and lag.

[0101] In some alternative implementations, the following methods can be used to detect water hammer effects in pumped storage systems:

[0102] The frequency regulation response of a pumped storage unit under a small load disturbance is analyzed using a water hammer effect detection controller, and the pump-turbine speed deviation ∆ω is utilized. pump Deviation from mechanical power ∆P m_pump Design a controller capable of detecting water hammer effects. When ∆ω pump With ∆P m_pump When the signs are the same, the water hammer effect occurs; when ∆ω pump Deviation from mechanical power ∆P m_pump When the signs are opposite, it is assumed that there is no water hammer effect.

[0103] For example, the water hammer effect is detected as follows:

[0104]

[0105] When the water hammer effect occurs, the hybrid power generation system first performs power compensation based on the designed wind turbine-energy storage hybrid frequency regulation strategy. In the primary frequency regulation, the wind turbine releases rotor kinetic energy to provide frequency support, and the energy storage battery compensates for the water hammer effect of pumped hydro storage and supports the wind turbine speed recovery, realizing the complementary advantages of wind and energy storage resources.

[0106] Further and optionally, a rotor kinetic energy strategy is employed to control the wind turbine system for frequency regulation. Rotor kinetic energy control utilizes the rotational kinetic energy of the wind turbine rotor for rapid frequency regulation, including virtual inertial control and droop control. Virtual inertial control simulates the inertia of a synchronous generator, adjusting the active power output according to the rate of frequency change; droop control adjusts the active power output according to the frequency deviation. The combination of these two approaches forms a comprehensive inertial control, achieving a superior frequency regulation effect. The specific steps are as follows:

[0107] S11, Obtain the frequency change rate and frequency deviation of the wind turbine system;

[0108] S12, determine the target frequency regulation power increment of the wind turbine system based on the frequency change rate and the frequency deviation, wherein the calculation expression for the target frequency regulation power is:

[0109]

[0110] In the formula, Δf represents the target frequency regulation power increment for the primary frequency regulation of the wind turbine; Δf represents the system frequency deviation. The rate of change of frequency; For virtual inertia coefficients, This is the droop coefficient;

[0111] S13, control the wind turbine system to perform frequency regulation based on the target frequency regulation power increment.

[0112] In this step, considering that the power output of the DFIG (Doubly Fed Induction Generator) in the wind turbine system gradually decreases during the speed recovery phase under droop control, its speed begins to recover. To prevent a secondary frequency drop during this process, the energy storage system needs to intervene in a timely manner to compensate for the power output reduction caused by the DFIG's withdrawal from frequency regulation.

[0113] Further and optionally, the step of controlling the energy storage system to perform power compensation includes:

[0114] S14, Calculate the current water hammer output compensation power required by the energy storage system. :

[0115]

[0116] In the formula, TB is the constant of the energy storage converter; , This is a self-adjusting energy storage rapid compensation coefficient based on operating status, used to accurately offset the reverse adjustment of pumped storage power; This represents the dynamics of a first-order inertial energy storage converter.

[0117] S15, Calculate the required compensation power of the energy storage system. :

[0118]

[0119] In the formula, For energy storage additional coefficient, The rated power of the fan system. This represents the real-time power of the wind turbine system. This refers to the rated power of the energy storage system.

[0120] in:

[0121]

[0122] In the formula; Let be the slope of the Logistic curve. The center point of the Logistic curve, This represents the maximum value of the energy storage additional coefficient;

[0123] S16, the current water hammer output compensation power With the energy storage support power The sum of these values ​​serves as the total power compensation power of the energy storage system. :

[0124]

[0125] S17, control the energy storage system based on the total power compensation power. Perform power compensation.

[0126] S20, determine the dead zone difference between the actual output of the thermal power system and the automatic power generation control command, and control the pumped storage system and the energy storage system to coordinate and compensate for the power to meet the dead zone difference.

[0127] In this embodiment, when the frequency regulation dispatch command changes, the thermal power system in the hybrid power generation system enters a new assessment phase and adjusts its power based on the command. However, due to its own technical characteristics, the actual output of the thermal power system differs significantly from the dead zone of the AGC (Automatic Generation Control) command in the same direction. To solve this problem, this embodiment proposes to use pumped storage and energy storage batteries to assist the thermal power system in secondary frequency regulation, thereby improving the frequency regulation performance of the system.

[0128] Furthermore, and optionally, in order to achieve optimal power allocation between the pumped storage unit and the energy storage battery during the secondary frequency regulation process, this embodiment also provides a power allocation strategy that divides the thermal power system into a response phase, a ramp-up phase, and a stabilization phase. Specifically, S20 includes:

[0129] S21, determine the current stage of the thermal power system, wherein the current stage includes one of the response stage, ramp-up stage, and stabilization stage;

[0130] S22, Determine the target compensation strategy for the pumped storage system and the energy storage system based on the current stage of the thermal power system;

[0131] S23, based on the same-direction dead zone difference, control the pumped storage system and the energy storage system to collaboratively compensate for the power that satisfies the same-direction dead zone difference according to the target compensation strategy.

[0132] In the technical solution provided in this embodiment, when the water hammer effect occurs, the rotor kinetic energy strategy is used to control the wind turbine system to adjust the frequency to provide frequency support. The energy storage battery compensates for the power reduction caused by the water hammer effect in pumped storage and supports the recovery of wind turbine speed, realizing the complementary advantages of wind and energy storage resources. On the other hand, the problem of dead zone difference between the actual output of the thermal power system and the automatic power generation control command is overcome by the coordinated power compensation of the pumped storage system and the energy storage system.

[0133] Second Embodiment

[0134] Based on the technical solution in the first embodiment, in traditional integrated inertial control, virtual inertial control and droop control work together on the wind turbine to provide frequency support. However, in order to further optimize the control effect, especially to reduce the impact of secondary frequency drops, this embodiment provides a method for improving the parameters of integrated inertial control, as follows:

[0135] 1) Improvement of virtual inertial control parameters

[0136] Traditional virtual inertial control simulates the inertial response of a synchronous generator by introducing the rate of change of frequency (dΔf / dt). To smooth the energy release process and avoid impacting the system near the lowest frequency point, this application introduces a first-order inertial element before the virtual inertial control parameter K1, resulting in a new virtual inertial control parameter K. 1,1 :

[0137]

[0138] Where T is the time constant and s is the Laplace operator.

[0139] The new virtual inertial control power is:

[0140]

[0141] 2) Improvement of droop control parameters

[0142] During the frequency recovery phase, to prevent the wind turbine from exiting frequency regulation due to prolonged low-speed operation and to mitigate the impact of secondary frequency drops, this application dynamically adjusts the droop control parameters. A Logistic function is introduced to make the droop control parameters change smoothly over time.

[0143]

[0144]

[0145] Where, k c The parameter t is used to control the rate of change. c Center point.

[0146] The new droop control power is:

[0147]

[0148] 3) Integrated inertial control with improved parameters

[0149] The combined improved virtual inertial control and droop control yields the following total frequency-modulated active power variation for the DFIG:

[0150]

[0151] In the initial stage of frequency regulation, virtual inertial control and droop control work together to provide frequency support. As the frequency recovers, virtual inertial control gradually weakens to zero to avoid absorbing energy from the grid and causing frequency fluctuations. Meanwhile, droop control automatically exits frequency regulation according to the change law of the Logistic function, reducing the risk of secondary frequency drops.

[0152] Third Embodiment

[0153] Based on any of the above embodiments, this embodiment provides a specific method for constructing a target compensation strategy, as follows:

[0154] (1) Establish a two-region load frequency control model

[0155] To accurately simulate the dynamic behavior of a multi-regional power system during secondary frequency regulation, this application establishes a two-regional load frequency control model incorporating both power generation and pumped storage conditions. This model employs tie-line frequency deviation control (TBC) mode, and its regional control error (ACE) is calculated using the following formula:

[0156]

[0157] in:

[0158] B i Let be the frequency deviation coefficient for region i, representing the sensitivity of that region to frequency deviation; Δf i (t) represents the frequency deviation of region i at time t; T ij Let ΔP be the synchronization power coefficient between region i and region j, representing the power transmission efficiency of the tie line between the two regions; tie,ij (t) represents the power deviation of the tie line between region i and region j at time t.

[0159] Through the TBC mode, this model can more comprehensively reflect the impact of inter-regional power exchange on system frequency.

[0160] (2) Design of storage-energy storage coordination control unit

[0161] 1. Response Phase

[0162] The frequency regulation response phase of a thermal power system begins at the AGC command update time. Configuring energy storage can quickly compensate for the dead zone difference between the thermal power system output and the AGC command. The goal of this phase is for the combined output of thermal power, energy storage, and energy storage to overcome the dead zone; therefore, the total power command that pumped storage and energy storage batteries need to respond to at time t is... for:

[0163]

[0164] During discharge During charging .

[0165] 2. Climbing phase

[0166] The addition of pumped storage and energy storage batteries makes the frequency regulation response phase of the thermal power system extremely short, which can be considered as entering the ramp-up phase the moment the AGC command is updated. Its objectives are: 1) to monitor the combined output of thermal power, pumped storage, and energy storage to avoid falling into the dead zone of the AGC command in the same direction and extend the response phase; 2) to monitor the difference between the thermal power system and the dead zone of the AGC command in real time, and only when the remaining total power of the pumped storage fully compensates for the difference, adjust the power deviation, end the ramp-up phase, and enter the stable phase.

[0167] During the ramp-up phase, the difference between the actual output of the thermal power system and the dead zone of the AGC command in the same direction, starting at time T1. for:

[0168]

[0169] 3. Stable Phase

[0170] The signal that a thermal power system enters the frequency regulation stabilization phase is when the combined output of thermal power, energy storage, and power storage crosses the dead zone where the unit's output and AGC commands are aligned. During this period, the control objective for energy storage is to minimize... and The deviation between them, the power command for storage is:

[0171]

[0172] (3) Formulation of target compensation strategy

[0173] To achieve optimal power allocation between pumped storage units and energy storage batteries during secondary frequency regulation, this application designs a detailed power allocation strategy, including a response phase, a ramp-up phase, and a stabilization phase.

[0174] During the response phase, the coordination control unit first calculates the dead-time difference between the thermal power system and the AGC command:

[0175]

[0176] in:

[0177] ΔP AGC (t) represents the power deviation of the AGC command at time t; ΔP deadband This refers to the dead zone power deviation of the thermal power system.

[0178] Then, the coordination and control unit starts the pumped storage unit and energy storage battery, and quickly compensates for the insufficient frequency regulation of the thermal power system by rapidly adjusting their output:

[0179]

[0180] in:

[0181] ΔP pump (t) represents the power deviation of the pumped storage unit at time t; ΔP bess (t) represents the power deviation of the energy storage battery at time t.

[0182] During the ramp-up phase, the coordination and control unit monitors the output deviation between the actual output of the thermal power system and the AGC command in real time, and dynamically adjusts the power distribution ratio between the pumped storage unit and the energy storage battery based on their frequency regulation capabilities.

[0183]

[0184]

[0185]

[0186] Where: α(t) is the dynamic allocation coefficient, representing the proportion of the pumped storage unit in the total power deviation; ΔP pump,cap (t) represents the available frequency regulation capacity of the pumped storage unit at time t; ΔP bess,cap(t) represents the available frequency regulation capacity of the energy storage battery at time t; ΔP error (t) represents the output deviation between the thermal power system and the AGC command.

[0187] During the steady-state phase, the primary objective of the coordination and control unit is to minimize the steady-state frequency deviation. At this time, the coordination and control unit will optimize the output distribution between the pumped storage unit and the energy storage battery based on their current states to minimize the steady-state frequency deviation.

[0188]

[0189] Where Δf1(t) and Δf2(t) are the steady-state frequency deviations of the dead zone and the linear response zone at time t, respectively.

[0190] Energy storage smooths out power output:

[0191]

[0192] In the formula, K droop Energy storage droop coefficient

[0193] Pumped storage provides baseline support:

[0194]

[0195] In the formula, Frequency deviation coefficient; Generator droop coefficient; This represents the change in system load.

[0196] Describing the above process in steps, omitting the model building and unit design sections, yields:

[0197] S221, when the thermal power system is in the response phase, control the pumped storage system and the energy storage system to coordinate compensation to meet the first power requirement of the same-direction dead zone difference. :

[0198]

[0199] In the formula, ΔP pump (t) represents the power deviation of the pumped storage unit at time t; ΔP bcss (t) represents the power deviation of the energy storage battery at time t;

[0200] S222, when the thermal power system is in the ramp-up phase, based on the available frequency regulation capacity of the pumped storage system and the energy storage system, determine the respective power allocation ratios of the pumped storage system and the energy storage system, and control the pumped storage system and the energy storage system to compensate for the second power that satisfies the same-direction dead zone difference while meeting their respective power allocation ratios. :

[0201]

[0202]

[0203] In the formula, α, All of these are power allocation ratios. Let t be the power deviation of the pumped storage system at time t. Let be the power deviation of the energy storage system at time t;

[0204] The calculation expression for the power allocation ratio is as follows:

[0205]

[0206] In the formula, Let t be the available frequency regulation capacity of the pumped storage system at time t; This represents the remaining frequency regulation capacity of the energy storage system.

[0207] S223, when the thermal power system is in a stable phase, optimize the processing allocation of the pumped storage system and the energy storage system with the goal of minimizing the steady-state frequency deviation.

[0208] S223 includes: S2231, determining the steady-state frequency deviation between the pumped hydro storage system and the energy storage system. :

[0209]

[0210] In the formula, Δf1(t) and Δf2(t) are the steady-state frequency deviations of the dead zone and the linear response zone at time t, respectively;

[0211] S2232, according to the state frequency deviation Determine the smooth output of the energy storage system :

[0212]

[0213] In the formula, K droop This refers to the energy storage droop factor.

[0214] S2233, according to the smooth output force Calculate the supporting output of the pumped storage system. :

[0215]

[0216] In the formula, Frequency deviation coefficient; Generator droop coefficient; This refers to the change in system load.

[0217] S2234, Control the energy storage system based on the smooth output Perform power compensation and control the pumped storage system based on the support output. Perform power compensation.

[0218] Fourth embodiment

[0219] Based on any of the above embodiments, this embodiment provides a dual-mode frequency regulation model for a hybrid power generation system. This model achieves power reserve through overspeed load shedding and pitch control, and combines virtual inertial control and droop control to form a comprehensive frequency regulation strategy for rotor kinetic energy. The power reserve control is as follows:

[0220] Power reserve control reserves a portion of active power to support system frequency regulation, and mainly includes overspeed load reduction control and pitch control.

[0221] Overspeed load reduction control: By increasing the rotor speed, the DFIG is made to operate at the suboptimal power point, reserving some power for frequency regulation.

[0222] Active power output of DFIG in unloaded mode:

[0223]

[0224] In the formula, This refers to the active power output by the wind turbine in MPPT mode; The second-best tip speed ratio; Cp,de is the wind energy utilization coefficient under the unloaded mode; Power tracking coefficient in unloaded mode.

[0225] Variable pitch control: By adjusting the pitch angle, the aerodynamic characteristics of the wind turbine are changed, and some power is reserved for frequency regulation.

[0226] Actual pitch angle:

[0227]

[0228] In the formula, This is a reference value for the propeller pitch angle; This is the pitch angle droop coefficient. The pitch angle that needs to be adjusted to correspond to changes in system frequency.

[0229] Fifth embodiment

[0230] Based on any of the above embodiments, this embodiment provides a mathematical model of a pumped storage system in a hybrid power generation system. This model includes a detailed mathematical model comprising a pump-turbine model, a governor model, and a servo system model. Details are as follows:

[0231] 1. Water pump turbine model:

[0232] The pump-turbine model of the water intake system describes the flow characteristics of water in the pipes and the conversion efficiency of the turbine blades for water flow. Its mathematical expression can be represented as:

[0233]

[0234]

[0235] Where Q is the flow rate, D is the pipe diameter, g is the gravitational acceleration, H is the head, ρ is the density of water, and η is the efficiency of the turbine.

[0236] 2. Speed ​​controller and servo system model:

[0237] The governor and servo system model is used to describe the response speed and control accuracy of pumped storage units to changes in grid frequency. The governor typically employs a PID controller, whose transfer function can be expressed as:

[0238]

[0239] Among them, K p K i K d These are the proportional, integral, and differential coefficients, respectively, and s is the Laplace variable.

[0240] Step 2.2: Establish a water hammer effect model and analyze the impact of water hammer effect on the frequency regulation performance of pumped storage units.

[0241] When pumped storage units rapidly adjust their output, the inertia of the water flow can cause a water hammer effect, resulting in a rapid reversal of the unit's output and affecting frequency regulation performance. To analyze the impact of the water hammer effect, this application introduces a water hammer effect detection and controller.

[0242] The mathematical description of the water hammer effect can be simplified to an inertial element, whose transfer function can be expressed as:

[0243]

[0244] Where Tw is the time constant of the water hammer effect.

[0245] Pumped-storage units are subject to water hammer effect during the initial stage of frequency regulation, resulting in power reversal, which exacerbates the system power deficit and worsens the frequency regulation effect. This application proposes to identify the inertial time constant of the water flow based on operating condition information, estimate the power disturbance by combining it with the rotor motion equation, and predict the unit output using a simplified speed regulation model to determine the maximum value of power reversal. This method allows for precise analysis of the impact of water hammer effect on the frequency regulation performance of pumped-storage units and provides a theoretical basis for optimizing frequency regulation control strategies to suppress power reversal and improve frequency regulation effectiveness.

[0246] Sixth Embodiment

[0247] Based on any of the above embodiments, this embodiment provides a mathematical model of an energy storage system in a hybrid power generation system, including a battery pack, an energy management system (BMS), a power conversion system (PCS), and an LC filter.

[0248] (1) Battery pack model:

[0249] The battery pack is the core component of an energy storage system. Its mathematical model can be simplified to an equivalent circuit, including parameters such as the battery's internal resistance, open-circuit voltage, and capacitance. The battery's output voltage Vbat can be expressed as:

[0250]

[0251] Where Eoc is the battery's open-circuit voltage, Ibat is the battery's output current, and Rint is the battery's internal resistance.

[0252] (2) SOC dynamic model

[0253] State of charge (SOC) is calculated by integrating charge and discharge power:

[0254]

[0255] In the formula, η lc E represents the charge / discharge efficiency (taken as 1). N For rated capacity, P lc (t) represents instantaneous power (positive for discharging and negative for charging).

[0256] (3) Power Conversion System (PCS) Model

[0257] The bidirectional DC / AC converter is dynamically simplified to an inertial element:

[0258]

[0259] Among them, T conv P is the time constant. ref This is the reference power.

[0260] (4) LC filter:

[0261] LC filters are used to suppress harmonic currents generated by PCS (Power Control System) and improve power quality. Their mathematical model can be represented as a second-order system with the following transfer function:

[0262]

[0263] Among them, L lc For the filter inductor, C dc_lc These are inductors and capacitors.

[0264] In addition, this embodiment also establishes a dynamic SOC model and sets charge and discharge limits to analyze changes in battery state of charge and prevent overcharging / over-discharging.

[0265] (5) SOC dynamic model

[0266]

[0267] In the formula: SOC(t) is the state of charge of the battery at time t; EN is the constant energy of the stored energy; η lc τ represents the efficiency of the charging / discharging circuit; P(τ) represents the energy storage power at any given time.

[0268] (6) Charge and discharge limiting

[0269] Dynamic charging and discharging power limiting. Automatic derating when the state of charge (SOC) approaches the safe limit to prevent overcharging / over-discharging.

[0270]

[0271] In the formula: P lc,lim SOC rate; P max / Pmin Maximum discharge / charge rate; SOC min / max For SOC lower / upper limits, △f db This is the energy storage frequency dead zone threshold.

[0272] Seventh Embodiment

[0273] Based on any of the above embodiments, this embodiment provides a simulation model and verification of the simulation results. (Refer to...) Figure 3 The diagram shown illustrates a dual-mode frequency regulation model for a wind turbine. The wind turbine's control strategy includes various control block diagrams and methods. In the block diagram for wind turbine overspeed and load reduction control, P... refd This represents the reference value of active power under overspeed load reduction control; the wind turbine pitch angle control block diagram is also included.

[0274] In virtual inertial control, d / dt is the differentiating element, but this element amplifies high-frequency fluctuations in the rate of change. To avoid this problem, a low-pass filter is connected in series after the differentiating element, and then multiplied by the inertial gain K. dTherefore, the additional active power ΔP generated when the wind turbine is under virtual inertial control can be obtained. d This value can be used as the active power setpoint for the rotor-side converter.

[0275] also, Figure 3 The diagram also shows a droop control block diagram. Virtual inertial control and droop control each have their own characteristics. Virtual inertial control stops providing active power or even absorbs energy after the frequency reaches its lowest point, and its response time is short; while droop control has a relatively slow response, but can continuously increase active power output as the frequency changes.

[0276] Given their complementary advantages, virtual inertial control and droop control are often used in combination. This combination of control strategies is called integrated inertial control, which is also shown in the figure. ΔP1 and ΔP2 are the virtual inertial control power and droop control power in integrated inertial control, respectively.

[0277] Furthermore, refer to Figure 4 The diagram shown is a structural schematic of a water pump turbine simulation model. pump_ref This is a reference value for the pump-turbine speed; ω pump Δμ is the actual operating speed of the pump-turbine; Δγ is the adjustment amount output by the governor; Δγ is the change in the turbine guide vane opening; ΔP m_pump This refers to the change in mechanical power of a pump-turbine reversible pump.

[0278] In addition, a multi-level model of the energy storage battery is designed, integrating frequency dead zone and SOC dynamic protection mechanisms to constrain charging and discharging power and ensure frequency regulation safety. The charging and discharging operation of the energy storage device is constrained by the battery's state of charge (SOC), referring to... Figure 5 The equivalent circuit of the lead-carbon battery is shown. and Corresponding to the voltage and current at the battery output terminal; U oc_lc When the lead-carbon battery is in an unloaded state (I lc Open-circuit voltage when R = 0); p C p For electrochemical polarization resistance and capacitance; C b To be with U oc_lc The capacitor that simulates the open-circuit voltage; R0 is the internal resistance in ohms; U b C b The terminal voltage of U; p For R p and C p The terminal voltage of R0; U0 is the terminal voltage of R0.

[0279] Lead-carbon batteries are powered by a controlled voltage source E lc and internal resistance R lc It is connected in series, and its simplified control circuit diagram is as follows: Figure 6 As shown.

[0280] To ensure that the energy storage system can effectively assist the pumped-storage unit in primary frequency regulation under different operating conditions, and to enable the pumped-storage unit to fully utilize its frequency regulation resources for secondary frequency regulation through wind-storage synergy to compensate for water hammer effects, a corresponding control strategy was designed for the system based on the operating conditions of the DFIG and the impact of water hammer effects on the pumped-storage unit, in order to adapt to the needs of different operating conditions.

[0281] Operating Condition 1: When the grid frequency is not lower than 49.98Hz, both the DFIG (doubly fed induction generator) and the pumped storage unit operate normally. If the SOC (State of Charge) of the energy storage device is detected to be at a low level, the charging process is initiated to restore the SOC, ensuring that the energy storage system has frequency regulation capability at all times.

[0282] Operating Condition 2: When the grid frequency is below 49.98Hz but not below 49.95Hz, select a portion of the DFIG units that meet the conditions and use a comprehensive inertia control strategy to participate in primary frequency regulation. If the DFIGs cannot continue frequency regulation due to speed convergence, and the current frequency performance still meets the standards, then switch to maximum wind energy control mode to maximize wind energy utilization; if the frequency performance does not meet the standards, the energy storage system will serve as backup capacity to assist in frequency regulation and ensure grid frequency stability.

[0283] Operating Condition 3: When the grid frequency is below 49.95Hz, the water hammer effect detection controller first determines whether the pumped storage unit (DFIG) is experiencing a water hammer effect. If no water hammer effect occurs, the DFIG group fully participates in frequency regulation using power reserve and rotor kinetic energy control strategies based on pre-defined grouping and parameter equivalent calculations (equivalent speed and equivalent electromagnetic power). If the frequency regulation effect is still insufficient, the energy storage system generates additional power to further stabilize the frequency. If a water hammer effect is detected, the wind-storage coordinated frequency regulation mechanism is immediately activated, with both the energy storage system and the DFIG group compensating for the impact of the water hammer effect on the grid. During the wind turbine speed recovery process, the energy storage system continuously generates additional power to assist in frequency regulation.

[0284] Based on actual operating data and characteristic analysis of wind turbines, equivalent parameter calculations are performed on different turbine groups, extracting equivalent rotational speed and equivalent electromagnetic power as key judgment criteria. These two parameters determine the operating range of the equivalent wind turbine model, thereby assessing the adequacy of frequency regulation resources for each turbine group. Based on the assessment results, appropriate control strategies are selected for different turbine groups, such as integrated inertia control, power reserve control, and rotor kinetic energy control, to ensure that wind turbine groups can effectively participate in system frequency regulation and improve the frequency stability and reliability of the entire power system.

[0285] To verify the advantages of the frequency modulation control strategy proposed in this application, a simulation model was constructed using the Matlab / Simulink platform. Figure 7 The simulation model shown illustrates a wind turbine cluster co-located with energy storage participating in primary frequency regulation. In this model, corresponding control strategies are employed for the equivalent turbine cluster under different operating conditions.

[0286] Specifically, the equivalent wind speeds of the four wind turbine groups are as follows: Figure 8 As shown in (b) of the figure. To comprehensively evaluate the performance of the proposed control strategy, a simulation analysis was conducted using a typical scenario of load surge as an example. In the simulation system, the rated frequency was set to 50Hz, the rated voltage of the transmission line was 230kV, and the total installed capacity of the wind farm was 75MW. Among them, the rated capacity of the thermal power system G1 was 100MW; the rated capacity of the pumped storage unit G2 was also 100MW; the installed capacity of the energy storage system was 4MW, and the rated power was 0.8MW. The loads connected to the system were load1 (117MW), load2 (37.5MW), load3 (26.5MW), and load4 (95MW). In addition, load5 (25MW) was connected as a disturbance load at 50s to verify the effectiveness of the proposed strategy.

[0287] Taking a sudden load increase as an example, the control strategy is shown in Table 1:

[0288] Table 1 Control Strategy

[0289]

[0290] Simulation results are as follows Figure 9 and Figure 10 As shown in Table 2, the results are obtained, where the frequency change rate RoCoF is defined as the average rate of change from the start of the frequency drop (initial frequency set to the nominal value of 50Hz) to the lowest frequency point:

[0291] Table 2 Comparison of system frequency regulation data under different control strategies

[0292]

[0293] Since pumped storage units primarily function for secondary frequency regulation, their impact on primary frequency regulation can be ignored. For example... Figure 11 As shown, the frequency modulation effect varies significantly under different control strategies:

[0294] (1) By comparing the primary frequency regulation effects of Strategy 1 and Strategy 2, the impact of pumped storage water hammer effect on frequency regulation performance can be verified. Under Strategy 1 without compensation for water hammer effect, the problem of pumped storage power reversal is prominent, leading to a minimum grid frequency f(t) nadir1 (49.7669Hz) and steady-state value f stThe lowest frequency (49.9419Hz) is observed, with a significant deterioration in the rate of frequency change RoCoF (-0.0762Hz / s). Strategy 2, because pumped storage does not participate in frequency regulation, does not suffer from the water hammer effect affecting frequency, but lacks the support of virtual inertia from wind storage, resulting in a lower minimum grid frequency f(t). nadir1 (49.8372Hz), rate of change of frequency RoCoF (-0.0668Hz / s), and steady-state value f st (49.9421Hz) is relatively low, only slightly higher than Strategy 1. Quantitative analysis shows that the water hammer effect of pumped storage increases the minimum frequency deviation of Strategy 1 by 30.16% and deteriorates RoCoF by 13.38%. However, Strategy 1 incorporates pumped storage into the secondary frequency modulation resources of the system, which can effectively improve the overall frequency modulation effect of the system and avoid the limitations of a single frequency modulation resource.

[0295] (2) In Strategy 3, the wind farm adopts the control strategy of this application to participate in frequency regulation (combining power reserve control and rotor kinetic energy control). Through the complementarity of the control strategy among the turbine groups, the frequency drop rate is slowed down and the water hammer effect is initially compensated, so that the minimum frequency is increased to 49.8763Hz (the minimum frequency deviation is reduced by 46.93% / 24.02% compared with Strategy 1 / 2), RoCoF is improved to -0.0543Hz / s (an increase of 29.60% / 18.73% compared with Strategy 1 / 2) and the steady-state value is significantly improved (49.9683Hz, the steady-state frequency deviation is reduced by 45.44% / 45.25% compared with Strategy 1 / 2); at the same time, the water hammer effect is compensated by pumped storage secondary frequency regulation, and the overall frequency regulation effect is significantly improved. However, since Strategy 3 does not consider the participation of energy storage in frequency regulation, there is a lack of active power output during the wind turbine speed recovery stage, the frequency drops twice, and the frequency regulation curve is not smooth enough.

[0296] (3) In Strategy 4, both wind and energy storage adopt the control strategy of this application, realizing a dual compensation mechanism for the water hammer effect: on the one hand, the wind farm provides rapid power support through rotor kinetic energy control, and on the other hand, the energy storage system accurately fills the power gap. The synergistic effect of the two significantly reduces the impact on grid equipment. This strategy has improved key frequency regulation indicators in all aspects: the minimum frequency has increased to 49.8916Hz (the minimum frequency deviation has decreased by 53.50% / 33.42% / 12.37% compared with Strategy 1 / 2 / 3), RoCoF has improved to -0.0521Hz / s (an increase of 32.46% / 22.03% / 4.07% compared with Strategy 1 / 2 / 3), and the steady-state value has increased to 49.9708Hz (the deviation has decreased by 49.74% / 49.57% / 7.89% compared with Strategy 1 / 2 / 3). In addition, the active power compensation of energy storage during the wind turbine speed recovery stage has increased the minimum deviation of the second frequency drop by 22.38%, effectively suppressing the second frequency drop. In summary, compared with other strategies, Strategy 4 organically integrates the advantages of wind, storage, and energy storage for frequency regulation. It not only overcomes the limitations of a single frequency regulation resource, but also shortens the preparation time for pumped storage secondary frequency regulation by about 40% through the timing coordination between resources, which is conducive to the overall optimization of frequency regulation effect.

[0297] Among them, the wind turbine clusters in strategies three and four are based on Figure 8 The equivalent wind speed distribution diagrams for each turbine group are shown, based on an adapted control strategy to fully utilize their frequency regulation resources to support grid frequency regulation. The equivalent rotational speed of the first turbine group satisfies 0.99ω. C ≤ω eq ≤1.01ω C It is located in the constant speed region, but the equivalent electromagnetic power does not satisfy P. e_eq >0.9P e_max Therefore, overspeed unloading is adopted to reserve power margin, and virtual inertia support is provided through integrated inertia control; the equivalent speed of the second group of machines satisfies ω B <ω eq <0.99ω C Located in the MPPT region, and with equivalent electromagnetic power satisfying P e_eq >0.55P e_max The third unit employs integrated inertia control for frequency modulation; the equivalent rotational speed of the third unit meets the requirement of 0.99 ω. C ≤ω eq ≤1.01ω C It is located in the constant speed region, and the equivalent electromagnetic power satisfies P e_eq >0.9P e_max The fourth turbine group employs variable pitch and overspeed load reduction to release reserve power for frequency regulation; the equivalent speed of the fourth turbine group does not meet the requirement of 0.99 ω. C ≤ω eq ≤1.01ω CLocated in the constant power region, variable pitch control is used to release reserve power for frequency regulation. The selection of this strategy combines the operating characteristics of each turbine group with the grid's frequency regulation requirements, maximizing the wind turbines' participation in frequency regulation. The active power response curves corresponding to the four equivalent turbine group strategies in the improved model of this application are shown below. Figure 10 As shown.

[0298] Energy storage compensates for water hammer effect output ΔP Bpump Energy storage compensates for the secondary drop of the wind turbine. The output ΔP Bwind and total energy storage output ΔP B like Figure 11 As shown:

[0299] Combination Figure 9 A comparison of the frequency regulation effects of different strategies reveals that energy storage can make the frequency regulation curve smoother and provide timely active power support when wind turbine frequency regulation resources are insufficient or the frequency drops twice.

[0300] Eighth embodiment

[0301] To verify the superiority of the frequency modulation control strategy proposed in this application, a simulation model was constructed based on the Matlab / Simulink platform, as shown below. Figure 12 The combined system three-zone frequency control model is shown.

[0302] Based on the wind-storage coordinated frequency regulation and water hammer effect compensation control strategy under the full wind speed scenario, region h includes models of thermal power systems, wind turbines, and pumped storage units; region i includes models of thermal power systems, wind turbines, pumped storage units, and energy storage batteries from Step 4; and region j only includes thermal power systems. Considering the characteristics of the power structure in some regions of my country, it is assumed that thermal power accounts for approximately 30% of the output in secondary frequency regulation in region h. Given the uncontrollability of wind power generation in Step 4, random load disturbances are added to the AGC systems of the three regions to make the models more realistic. Simulations are conducted and compared for the model of region j without pumped storage, the model of region h with pumped storage, and the model of region i with both pumped storage and energy storage.

[0303] Figure 13 The global performance of secondary frequency modulation was demonstrated in three scenarios. Figure 14 The deviations of transient (a) and steady-state frequencies (b) were compared separately. The results show that configuring pumped storage and energy storage simultaneously is significantly better than the case without pumped storage or pumped storage for frequency regulation alone in terms of both transient and steady-state frequency deviations.

[0304] by Figure 14Taking (b) as an example, without pumped storage, the maximum steady-state frequency deviation of the region is 0.0103Hz; after adding pumped storage, the deviation drops to 0.0063Hz, a reduction of 39.3%, and the frequency recovery speed is faster, effectively suppressing frequency fluctuations between regions; when pumped storage and energy storage are configured at the same time, the deviation further drops to 0.0047Hz, and compared with pumped storage frequency regulation alone, the maximum frequency deviation of the region is reduced by 25.4%.

[0305] like Figure 15 As shown, when the time period of 270-300s is selected, the output adjustment range of pumped storage is about 4-5 times that of thermal power system, indicating that its adjustment capability is stronger.

[0306] Pumped hydro storage, when applied to frequency regulation, can increase reserve capacity, enhance system anti-interference capabilities, and accelerate the recovery speed of frequency and tie-line fluctuations, providing strong support for the power grid. Under ARR (Automatic Reduction) mode, the continuous output of energy storage can effectively improve steady-state frequency deviation, further reduce frequency fluctuations, and significantly enhance system frequency regulation performance. Figure 16 The corresponding energy storage response AGC outputs power.

[0307] Based on the above research, the energy storage-storage coordinated control strategy proposed in this application has significant advantages in improving system frequency stability. It can effectively suppress transient frequency fluctuations in the power system, significantly reduce steady-state frequency deviation, and comprehensively improve the secondary frequency regulation performance of the system.

[0308] As one implementation scheme, Figure 17 This is a schematic diagram of the hardware operating environment of the computer system involved in the embodiments of this application.

[0309] like Figure 17 As shown, the computer system may include: a processor 1001, such as a CPU; a memory 1005; a user interface 1003; a network interface 1004; and a communication bus 1002. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen or an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wi-Fi interface). The memory 1005 may be high-speed RAM or non-volatile memory, such as a disk drive. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0310] Those skilled in the art will understand that Figure 1The computer system architecture shown does not constitute a limitation on the computer system and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0311] like Figure 17 As shown, the memory 1005, as a storage medium, may include an operating system, a network communication module, a user interface module, and computer programs. The operating system is a program that manages and controls the hardware and software resources of the computer system, as well as the operation of the computer programs and other software or programs.

[0312] exist Figure 17 In the computer system shown, the user interface 1003 is mainly used to connect to the terminal and communicate with the terminal; the network interface 1004 is mainly used to communicate with the backend server; and the processor 1001 can be used to call the computer program stored in the memory 1005.

[0313] In this embodiment, the computer system includes: a memory 1005, a processor 1001, and a computer program stored in the memory and executable on the processor, wherein:

[0314] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0315] S10, when a water hammer effect is detected in the pumped storage system, the rotor kinetic energy strategy is used to control the wind turbine system to adjust the frequency, and when the output power of the wind turbine system decreases, the energy storage system is controlled to perform power compensation.

[0316] S20, determine the dead zone difference between the actual output of the thermal power system and the automatic power generation control command, and control the pumped storage system and the energy storage system to coordinate and compensate for the power to meet the dead zone difference.

[0317] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0318] S11, Obtain the frequency change rate and frequency deviation of the wind turbine system;

[0319] S12, determine the target frequency regulation power increment of the wind turbine system based on the frequency change rate and the frequency deviation, wherein the calculation expression for the target frequency regulation power is:

[0320]

[0321] In the formula, Δf represents the target frequency regulation power increment for the primary frequency regulation of the wind turbine; Δf represents the system frequency deviation. The rate of change of frequency; For virtual inertia coefficients, This is the droop coefficient;

[0322] S13, control the wind turbine system to perform frequency regulation based on the target frequency regulation power increment.

[0323] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0324] Both the virtual inertia coefficient and the droop coefficient are adjusted with the rate of change of frequency;

[0325] Among them, the adjusted virtual inertial parameters Satisfy the following expression:

[0326]

[0327] In the formula, the time constant T is proportional to the output power and frequency modulation exit time under virtual inertial control, and s is the Laplace operator;

[0328] Among them, the adjusted droop parameter K 2,1 Satisfy the following expression:

[0329]

[0330] In the formula, t is the current simulation time, t re k is the time for the wind turbine to exit frequency regulation. c Parameters used to control the rate of change.

[0331] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0332] S14, Calculate the current water hammer output compensation power required by the energy storage system. :

[0333]

[0334] In the formula, TB is the constant of the energy storage converter; , This is a self-adjusting energy storage rapid compensation coefficient based on operating status, used to accurately offset the reverse adjustment of pumped storage power; This represents the dynamics of a first-order inertial energy storage converter.

[0335] S15, Calculate the required compensation power of the energy storage system. :

[0336]

[0337] In the formula, For energy storage additional coefficient, The rated power of the fan system. This represents the real-time power of the wind turbine system. This refers to the rated power of the energy storage system.

[0338] in:

[0339]

[0340] In the formula; Let be the slope of the Logistic curve. The center point of the Logistic curve, This represents the maximum value of the energy storage additional coefficient;

[0341] S16, the current water hammer output compensation power With the energy storage support power The sum of these values ​​serves as the total power compensation power of the energy storage system. :

[0342]

[0343] S17, control the energy storage system based on the total power compensation power. Perform power compensation.

[0344] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0345] The energy storage rapid compensation coefficient satisfy:

[0346]

[0347] In the formula, This represents the energy storage baseline compensation coefficient, used to adjust the compensation intensity for water hammer effect; Indicates the angular velocity of the fan rotor;

[0348] If the frequency of the doubly-fed asynchronous wind turbine after it is removed from frequency regulation still does not meet the frequency requirements, then a new energy storage droop compensation coefficient K is needed. B2,1 satisfy;

[0349]

[0350] The energy storage support power satisfy:

[0351]

[0352] in:

[0353]

[0354] .

[0355] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0356] S21, determine the current stage of the thermal power system, wherein the current stage includes one of the response stage, ramp-up stage, and stabilization stage;

[0357] S22, Determine the target compensation strategy for the pumped storage system and the energy storage system based on the current stage of the thermal power system;

[0358] S23, based on the same-direction dead zone difference, control the pumped storage system and the energy storage system to collaboratively compensate for the power that satisfies the same-direction dead zone difference according to the target compensation strategy.

[0359] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0360] S221, when the thermal power system is in the response phase, control the pumped storage system and the energy storage system to coordinate compensation to meet the first power requirement of the same-direction dead zone difference. :

[0361]

[0362] In the formula, ΔP pump (t) represents the power deviation of the pumped storage unit at time t; ΔP bcss (t) represents the power deviation of the energy storage battery at time t;

[0363] S222, when the thermal power system is in the ramp-up phase, based on the available frequency regulation capacity of the pumped storage system and the energy storage system, determine the respective power allocation ratios of the pumped storage system and the energy storage system, and control the pumped storage system and the energy storage system to compensate for the second power that satisfies the same-direction dead zone difference while meeting their respective power allocation ratios. :

[0364]

[0365]

[0366] In the formula, α, All of these are power allocation ratios. Let t be the power deviation of the pumped storage system at time t. Let be the power deviation of the energy storage system at time t;

[0367] The calculation expression for the power allocation ratio is as follows:

[0368]

[0369] In the formula, Let t be the available frequency regulation capacity of the pumped storage system at time t; This represents the remaining frequency regulation capacity of the energy storage system.

[0370] S223, when the thermal power system is in a stable phase, optimize the processing allocation of the pumped storage system and the energy storage system with the goal of minimizing the steady-state frequency deviation.

[0371] When processor 1001 calls a computer program stored in memory 1005, it performs the following operations:

[0372] S2231, Determine the steady-state frequency deviation between the pumped hydro storage system and the energy storage system. :

[0373]

[0374] In the formula, Δf1(t) and Δf2(t) are the steady-state frequency deviations of the dead zone and the linear response zone at time t, respectively;

[0375] S2232, according to the state frequency deviation Determine the smooth output of the energy storage system :

[0376]

[0377] In the formula, K droop This refers to the energy storage droop factor.

[0378] S2233, according to the smooth output force Calculate the supporting output of the pumped storage system. :

[0379]

[0380] In the formula, Frequency deviation coefficient; Generator droop coefficient; This refers to the change in system load.

[0381] S2234, Control the energy storage system based on the smooth output Perform power compensation and control the pumped storage system based on the support output. Perform power compensation.

[0382] Furthermore, those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program includes program instructions and can be stored in a storage medium, which is a computer-readable storage medium. The program instructions are executed by at least one processor in a computer system to implement the process steps of the embodiments of the above methods.

[0383] Therefore, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the various steps of the frequency regulation control optimization method based on the wind-storage-energy storage combined system as described in the above embodiments.

[0384] The computer-readable storage medium can be any computer-readable storage medium capable of storing program code, such as a USB flash drive, portable hard drive, read-only memory (ROM), magnetic disk, or optical disk.

[0385] It should be noted that, since the storage medium provided in the embodiments of this application is the storage medium used to implement the methods of the embodiments of this application, those skilled in the art can understand the specific structure and variations of the storage medium based on the methods described in the embodiments of this application, and therefore will not be repeated here. All storage media used in the methods of the embodiments of this application fall within the scope of protection of this application.

[0386] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0387] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0388] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0389] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0390] It should be noted that any reference signs placed between parentheses in the claims should not be construed as limiting the claims. The word "comprising" does not exclude the presence of components or steps not listed in the claims. The word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. This application can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. In a unit claim enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0391] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0392] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for frequency control optimization based on a wind-pumped-storage combined system, characterized in that, The method is applied to a hybrid power generation system including a fan system, a pumped storage system, an energy storage system and a thermal power system, and comprises the following steps: S10, when water hammer effect in the pumped storage system is detected, a rotor kinetic energy strategy is used to control the fan system to perform frequency regulation, and the energy storage system is controlled to perform power compensation when the output power of the fan system is reduced; S20, a same-direction dead zone difference value between actual output of the thermal power system and an automatic generation control instruction is determined, and the pumped storage system and the energy storage system are controlled to cooperatively compensate for power meeting the same-direction dead zone difference value; In the S10, the step of controlling the energy storage system to perform power compensation comprises: S14, calculating the current water hammer output compensation power required for compensation of the energy storage system : ； where T B is the energy storage converter constant; , is the energy storage fast compensation coefficient self-adjusted according to the operating state, used to precisely offset the inverse adjustment of the pumped storage power; represents the first-order inertia link energy storage converter dynamics; S15, calculating a required compensated energy storage support power of the energy storage system : ； In the formula, is the energy storage additional coefficient, is the rated power of the fan system, is the real-time power of the fan system; is the rated power of the energy storage system; In the S10, the step of controlling the fan system to perform frequency regulation using the rotor kinetic energy strategy comprises the following steps: ； wherein is the slope of the Logistic curve, is the center point of the Logistic curve, is the maximum value of the energy storage additional coefficient; S16, compensating power of the current water hammer force with the energy storage support power as the total power compensation power of the energy storage system : ； S17, control the energy storage system to compensate total power based on the power power compensation is performed.

2. The method of claim 1, wherein, S11, a frequency change rate and a frequency deviation of the fan system are obtained; S12, a target frequency regulation power increment of the fan system is determined according to the frequency change rate and the frequency deviation, wherein a calculation expression of the target frequency regulation power is: S13, the fan system is controlled to perform frequency regulation based on the target frequency regulation power increment. ； In the formula, is the target frequency modulation power increment of the fan primary frequency modulation; Δf is the system frequency deviation; is the frequency change rate; is the virtual inertia coefficient, is the droop coefficient; The virtual inertia coefficient and the droop coefficient are adjusted according to the frequency change rate; 3. The method of claim 2, wherein, In the formula, a time constant T is proportional to the output power under virtual inertia control and frequency regulation exit time, and s is a Laplace operator; wherein the adjusted virtual inertia parameter satisfies the following expression: ； In the S20, specifically comprises: wherein the adjusted droop parameter K 2,1 satisfies the following expression: ； In the formula, t is the current simulation time, t re is the fan exit frequency modulation time, k c is the parameter for controlling the rate of change.

4. The method of claim 1, wherein, The energy storage quick compensation coefficient satisfies: ； In the formula, represents the energy storage reference compensation coefficient, used to adjust the water hammer effect compensation strength; represents the fan rotor angular velocity; If the frequency of the doubly-fed asynchronous wind generator after exiting the frequency modulation still does not meet the frequency requirement, a new energy storage droop quick compensation coefficient K B2,1 satisfies: ； The energy storage support power satisfies: ； S21, a current stage of the thermal power system is determined, and the current stage comprises one of a response stage, a climbing stage and a stable stage; ； 。 5. The method of claim 1, wherein, S22, a target compensation strategy of the pumped storage system and the energy storage system is determined according to the current stage of the thermal power system; S23, the pumped storage system and the energy storage system are controlled to cooperatively compensate for power meeting the same-direction dead zone difference value according to the same-direction dead zone difference value and the target compensation strategy. The target compensation strategy comprises: In the formula, a calculation expression of the power distribution ratio is:

6. The method of claim 5, wherein, S223, when the thermal power system is in the stable stage, processing distribution of the pumped storage system and the energy storage system is optimized to minimize the steady-state frequency deviation. S221, when the thermal power system is in a response stage, controlling the pumped storage system and the energy storage system to jointly compensate for a first power meeting the same-direction dead-band difference value : ； wherein ΔP pump (t) is the power deviation of the pumped storage unit at time t; ΔP bcss (t) is the power deviation of the energy storage battery at time t; S222, when the thermal power system is in a climbing stage, according to available frequency modulation capacities of the pumped storage system and the energy storage system, determining respective power distribution proportions of the pumped storage system and the energy storage system, and controlling the pumped storage system and the energy storage system to compensate for a second power satisfying the same-direction dead-band difference according to the respective power distribution proportions : ； ； In the formula, α, are power distribution ratios, is a power deviation of the pumped storage system at time t, is a power deviation of the energy storage system at time t; In the S223, the step of optimizing the processing distribution of the pumped storage system and the energy storage system to minimize the steady-state frequency deviation comprises: ； In the formula, is the available frequency modulation capacity of the pumped storage system at time t; is the remaining frequency modulation capacity of the energy storage system; In the formula, Δf1(t) and Δf2(t) are steady-state frequency deviations of the dead zone and the linear response zone at time t, respectively; 7. The method of claim 6, wherein, The computer system comprises a memory, a processor and a computer program stored on the memory and executable on the processor, and the computer program is executed by the processor to implement the steps of the frequency regulation control optimization method based on the wind-pumped-storage combined system according to any one of claims 1 to 7. S2231, determining a steady state frequency deviation in the pumped hydro energy storage system and the energy storage system : ； The computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the steps of the frequency regulation control optimization method based on the wind-pumped-storage combined system according to any one of claims 1 to 7. S2232, determining the state frequency deviation based on the frequency deviation determining a smoothed output of the energy storage system : ； In the formula, K droop is the energy storage droop coefficient; S2233, based on the smoothed output calculating a support output of the pumped storage system : ； In the formula, a frequency deviation coefficient; a generator droop coefficient; a system load change amount; S2234, controlling the energy storage system to provide power compensation based on the smoothed output power performing power compensation, and controlling the pumped hydro energy storage system based on the support power performing power compensation.

8. A computer system, characterized by ​ 9. A computer-readable storage medium, characterized in that, ​

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