Wind-storage-load collaborative control method and device considering deep-sea wind farm restraint control

Abstract

The present application relates to the field of power system frequency control, specifically to a wind-storage-load collaborative control method and device considering far-offshore wind farm damping control, the method steps comprising: obtaining power system data and wind turbine and damping controller parameters; establishing a wind farm single-machine equivalent model considering wind farm damping control; constructing a wind-storage-load collaborative power system frequency control optimization problem under serious fault, taking the frequency regulation stage duration of the disturbed energy storage output power, demand response power and damping signal as the control variable; solving the frequency control optimization problem based on the sensitivity method to obtain the optimal control strategy of wind power and energy storage. Compared with the prior art, the single-machine equivalent model considering wind farm damping control established by the present application has good applicability in frequency calculation, and the offshore wind farm damping signal is optimized collaboratively with energy storage and demand response, which can meet the system frequency safety requirements while having good economy.

Description

Technical Field

[0001] This invention belongs to the field of new power system frequency control, and in particular relates to a wind-storage-load coordinated frequency control method and device for power systems that takes into account the restraint control of deep-sea wind farms. Background Technology

[0002] In recent years, new energy sources, represented by wind power and photovoltaics, have developed rapidly. The substitution effect of these new energy sources has led to a continuous decrease in system inertia and insufficient frequency regulation capabilities, posing challenges to system frequency security. Therefore, various countries have stipulated that grid-connected new energy sources should have a certain degree of active frequency and voltage support capabilities. According to my country's "Technical Regulations for Wind Farm Grid Connection," grid-connected wind power and photovoltaics should have primary frequency regulation capabilities to ensure frequency system security.

[0003] Domestic and international experts have conducted extensive research on wind power frequency regulation control, proposing methods such as synthetic inertia (SI), pitch angle control, overspeed control, and distributed consistency control. SI control increases wind turbine power by releasing rotor kinetic energy, providing a certain frequency support. The increased power is equal to the sum of the droop control and inertial control components. To suppress the potential "secondary frequency drop" (SFD) phenomenon, fuzzy control or trajectory optimization methods are often used to improve SI control performance. Pitch angle control and overspeed control are both load shedding controls, which can provide reliable backup, but they are less economical and cause more severe mechanical wear. Therefore, rotor kinetic energy-based control methods are more commonly used. For large-scale wind farms, wind speed distribution characteristics cannot be ignored, and the frequency regulation potential of wind turbines varies greatly. The frequency regulation dynamics of wind farms will have strong uncertainties, posing challenges to wind power frequency regulation control.

[0004] For example, the solutions disclosed in Chinese patent applications CN202311354168.8 and CN202411607909.3, etc., currently have shortcomings in research on wind power frequency regulation control, mainly including: 1) There is insufficient research on frequency calculation methods that take into account wind speed distribution characteristics. Large-scale wind farms are characterized by a large number of wind turbines, high model order, and complex calculations. Direct simulation will face the "curse of dimensionality" problem, while obtaining multi-turbine equivalent models is difficult due to the difficulty in obtaining detailed wind speed data within the farm.

[0005] 2) Methods for mitigating SFD risks that may result from wind power frequency regulation still need further research. Wind turbine rotor kinetic energy is limited; how to release rotor kinetic energy in an orderly manner according to system frequency regulation needs and the available kinetic energy of the unit to ensure system frequency safety is a problem that needs further investigation.

[0006] 3) There is limited consideration given to the synergy between wind power frequency regulation and other control measures. Existing studies have mostly focused on wind power frequency regulation in isolation. However, in cases of severe faults, wind power frequency regulation alone cannot guarantee frequency safety. In such situations, wind power frequency regulation needs to be coordinated with other measures such as DC power support, energy storage, and demand response. These various controls have different adjustable capacities, control costs, and response speeds. How to achieve coordinated control is a problem that wind power frequency regulation needs to address. Summary of the Invention

[0007] The purpose of this invention is to overcome the problems of difficulty in calculating the frequency of wind power systems, the risk of SFD in wind power frequency regulation, and insufficient consideration of the coordination of multiple frequency control measures in the existing technology, and to provide a wind-storage-load coordinated frequency control method for power systems that takes into account the restraint control of deep-sea wind farms.

[0008] The objective of this invention can be achieved through the following technical solutions: As a first aspect of the present invention, a wind-storage-load coordinated control method considering the restraint control of deep-sea wind farms is provided, the method comprising the following steps: Acquire power system data and parameters of wind turbines and traction controllers; Establish an equivalent model of a single wind turbine that takes into account the wind farm's control and restraint mechanisms; Under severe fault conditions, a wind-storage-load coordinated power system frequency control optimization problem is constructed with the goal of minimizing the economic cost of frequency control. The frequency control optimization problem uses the energy storage output power after disturbance, the demand response power, and the frequency regulation phase duration of the restraint signal as control variables. The optimal control strategy for wind power and energy storage is obtained by solving the frequency control optimization problem of the power system based on the sensitivity method.

[0009] As a preferred technical solution, the power system data includes: Synchronous generator capacity Inertial time constant and damping coefficient For steam turbine generators, governor parameters include governor gain. reheater coefficient Reheater time constant and the governor time constant For hydro-generators, governor parameters include gain. Water hammer effect time constant and the time constant of the turbine governor ; Energy storage system control parameters, including maximum adjustable power. Cost factor c 1 and response timet ES ; Demand response control parameters, including maximum adjustable power Cost factor c 2 and response time t dr .

[0010] As a preferred technical solution, the parameters of the wind turbine and the traction controller include: Wind farm wiring l-k impedance between and wind turbines capacity Inertial time constant and generator terminal transformer capacity S Ti and short-circuit impedance Z Ti ; Obtain the wind farm's traction control topology and traction controller parameters, including proportional and integral coefficients. .

[0011] As a preferred technical solution, the specific details of establishing the equivalent model of a single wind turbine considering wind farm restraint control are as follows: The equivalent capacity of a wind turbine is equal to the sum of the capacities of all wind turbine units within the wind farm; Mechanical power captured by an equivalent wind turbine in steady state before disturbance The output power at the grid connection point of the wind farm is equal to With losses within the wind farm The sum; based on the maximum power point tracking curve of the wind turbine, calculate the corresponding equivalent wind turbine speed. And based on the equivalent wind turbine speed and maximum tip speed ratio Find the equivalent wind turbine unit wind speed The connection impedance between the equivalent wind turbine and the common coupling point is set as follows: In the formula, n lk For the line l-k Number of upstream wind turbine units For the power lines within the wind farm l-k The impedance between them n w This represents the total number of wind turbines in the wind farm. During frequency regulation, the kinetic energy released by the equivalent wind turbine is equal to the additional power generated by each wind turbine in the wind farm during the frequency regulation process. sum: The wind turbine i The power generated during frequency modulation It is expressed as follows: In the formula, Signal control for wind farms; For wind turbine consistent state variables; For communication weight; Indicates whether the wind turbine receives a restraint signal; The parameters for the restraint controller are represented by the proportional coefficient and integral coefficient of the restraint control, respectively. This represents the set of wind turbine unit numbers. This represents the total number of wind turbines in the wind farm. After frequency regulation and steady state, the equivalent mechanical power captured by the wind turbine Approximately the mechanical power of all wind turbine units sum.

[0012] As a preferred technical solution, the restraining signal The expression is: In the formula, The moment the fault begins. This marks the boundary between the frequency modulation phase and the recovery phase. Recorded as , This refers to the time when the frequency modulation control exits; parameters A positive number is used to control the speed recovery rate. b The smaller the value, the slower the speed recovery; It is a decimal, used to ensure exist Continuity of time.

[0013] As a preferred technical solution, the frequency control optimization problem of constructing a wind-storage-load coordinated power system adopts frequency security indicators. To comprehensively evaluate the frequency security of the system, specifically including: Initial rate of change of frequency The frequency change rate within a set time after the disturbance is taken to reflect the frequency change rate in the initial time period after the disturbance occurs. The lowest frequency of the two frequency drops , ; Peak frequency during the two drops , The amplitude of the first oscillation of frequency during the dynamic process ; steady-state frequency after fault .

[0014] As a preferred technical solution, the wind-storage-load coordinated power system frequency control optimization problem aims to minimize the economic cost of frequency control and the output power of energy storage after disturbance. Demand response power and restraint signals Frequency modulation phase duration For the control variables to be optimized The description is as follows: In the formula, The economic cost of frequency control; c 1. c 2. Cost factors for energy storage and demand response respectively; This represents the nonlinear dynamic mapping relationship between control measures and system frequencies; The initial rate of change of frequency Maximum value; To set the decimal; This is the lowest frequency value; This is the lowest frequency allowed by the system in steady state. This represents the minimum steady-state frequency after the fault. , These are the parameters of the restraint signal. The upper and lower bounds of the adjustment; , These are the upper bounds of the energy storage output power and the demand response power after the disturbance, respectively.

[0015] As a preferred technical solution, the frequency control optimization problem of the wind-storage-load coordinated power system is solved iteratively using a sensitivity-based approximate linearization method, with the following steps: Randomly initialize control variables ; The corresponding system frequency response curve is calculated through numerical simulation. And calculate the security indicators for each frequency; Frequency safety indicators are obtained using the perturbation method. For control variables The sensitivity of the frequency control optimization problem is transformed into a linear programming problem by converting all safety index constraint inequalities into linear inequalities. Solve the resulting linear programming problem, obtain the changes in the control variables, and determine the control variables to be optimized. Make corrections; Repeat the optimization until the change in the control variable is less than the set threshold.

[0016] As a second aspect of the present invention, an electronic device is provided, comprising: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the wind-storage-load coordinated control method as described above, which takes into account the restraint control of deep-sea wind farms.

[0017] As a third aspect of the present invention, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the wind-storage-load coordinated control method as described above, taking into account the restraint control of deep-sea wind farms.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1) For wind farms that take into account the constraint and consistency control, this invention constructs an equivalent model of a single wind farm unit that can be used for rapid frequency calculation, establishes a mathematical model of the wind-storage-load coordinated frequency control problem, and applies the sensitivity method to solve the optimal control measures such as wind power constraint signal, energy storage, and demand response, which is of great significance for improving the frequency security of new power systems.

[0019] 2) The wind farm single-unit equivalent model established by the method of the present invention, which takes into account the restraint control of deep-sea wind farms, has less calculation time, avoids the "curse of dimensionality", and has good accuracy due to the consistency of the dynamic behavior of the units in the field. It can meet the requirements of system frequency calculation under large disturbance conditions and has good adaptability.

[0020] 3) This invention establishes a wind-storage-load coordinated frequency control strategy, which coordinates and optimizes wind farm control signals, energy storage, and demand response. While meeting the system frequency security requirements, it can reduce costs and has good economic efficiency. Attached Figure Description

[0021] Figure 1 A flowchart illustrating the steps of a power system wind-storage-load coordinated frequency control method considering the restraint control of deep-sea wind farms, provided in an embodiment of the present invention; Figure 2 A schematic diagram of a 3-unit, 9-node offshore wind farm access system provided in an embodiment of the present invention; Figure 3 The diagram shows a comparison of wind power and system frequency response curves when disturbances occur in the equivalent model and detailed model of a single offshore wind farm provided in this embodiment of the invention. In the diagram, (a) is the wind power curve and (b) is the frequency response curve; the solid line represents the detailed model and the dashed line represents the equivalent model of a single unit. Figure 4A flowchart of the sensitivity-based approximate linearization solution method provided in an embodiment of the present invention; Figure 5 The frequency response curves of the single-machine equivalent model under different restraint signals are provided in the embodiments of the present invention. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0023] Example 1 This invention addresses the challenges of frequency calculation in wind power systems, the risk of spontaneous energy depletion (SFD) in wind power frequency regulation, and insufficient consideration of the synergistic effects of various frequency control measures in existing research. It proposes a wind-storage-load coordinated frequency control method for power systems that considers the constraint control of deep-sea wind farms. For wind farms considering constraint consistency control, this method constructs an equivalent model of a single wind farm unit for rapid frequency calculation, establishes a mathematical model of the wind-storage-load coordinated frequency control problem, and applies sensitivity methods to solve for optimal control measures such as wind power constraint signals, energy storage, and demand response. Figure 1 As shown, the power system wind-storage-load coordinated frequency control method of the present invention includes the following steps: Step 1: Obtain power system data, as well as wind farm, wind turbine, and traction controller parameters; Step 2: Establish an equivalent model of a single wind turbine in the wind farm, taking into account the wind farm's control and restraint. Step 3: Construct a wind-storage-load coordinated power system frequency control optimization problem; Step 4: Solve the power system frequency control optimization problem based on the sensitivity method to obtain the optimal control strategy for wind power and energy storage.

[0024] Specifically, in step (1), the power system data and the parameters of the wind turbine and traction controller are acquired. The implementation process is as follows: Acquire power system data, including synchronous generators capacity Inertial time constant and damping coefficient , , This refers to the number of synchronous generators; for steam turbine generators, the governor parameters include the governor gain. reheater coefficient Reheater time constant and the governor time constant For hydro-generators, the governor parameters include gain. Water hammer effect time constant and the time constant of the turbine governor Acquire control parameters of the energy storage system, including maximum adjustable power. Cost factor c 1 and response time t ES Obtain demand response control parameters, including maximum adjustable power. Cost factor c 2 and response time t dr .

[0025] Obtain parameters of wind farms and wind turbines, including the wiring within the wind farm. l-k impedance between , , , l , k Here, m represents the node numbering within the wind farm, where m is the total number of nodes in the wind farm; and the number of wind turbine generators. capacity Inertial time constant and generator terminal transformer capacity S Ti and short-circuit impedance Z Ti , , The total number of wind turbines in the wind farm; define wind turbine units. Consistent state variables : (1) In the formula: For wind turbines rotational speed, for The initial rotational speed, The minimum permissible speed of wind turbine units, Reflects wind turbine The proportion of the remaining rotor kinetic energy to the available rotor kinetic energy.

[0026] Obtain the wind farm traction control topology, if the wind turbine Towards When state variables are passed, the communication weight is... a ij =1, otherwise, a ij =0; When the wind turbine receives a restraint signal ,otherwise, Obtain the parameters of the restraint controller, including the proportional and integral coefficients. Assume the wind farm control signal is According to the restraint control algorithm, the wind turbine unit The power generated during frequency modulation : (2) In the formula: This represents the set of wind turbine unit numbers. This represents the total number of wind turbines in the wind farm.

[0027] In step (2), an equivalent model of a single wind turbine considering the wind farm's control and restraint is established. The implementation process is as follows: When a single unit is of equivalent value, an equivalent wind turbine is assumed. The capacity is Furthermore, the wind turbines within the wind farm all have the same capacity. ,but Let the steady-state output power of the wind farm at the grid connection point before the disturbance be... In-field losses are The total mechanical energy captured by the wind turbines in the field is then... According to the principle of power conservation, the equivalent wind turbine in steady state Captured mechanical power and Equal; based on the maximum power point tracking curve of the wind turbine, the corresponding equivalent turbine speed can be calculated. ,in To determine the optimal power coefficient of the wind turbine, based on the equivalent machine speed... and maximum tip speed ratio The equivalent value of the wind turbine unit can be calculated. wind speed Based on the principle of constant power loss, the power collection network is equivalently valued, and an equivalent wind turbine is assumed. The connection impedance between the common connection point and the common connection point is ,but: (3) In the formula: n lk For the line l-k Number of upstream wind turbine units For the power lines within the wind farm l-k The impedance between them n w This represents the total number of wind turbines in the wind farm.

[0028] Wind turbine during frequency regulation Output power For captured mechanical power The increased power generated by releasing rotor kinetic energy The sum of the equivalent kinetic energy; since the equivalent kinetic energy before the disturbance is required to be equal to the sum of the kinetic energies of the wind turbines in the wind farm, and the release rate of kinetic energy of each unit is consistent under the restraint control, it can be deduced that the equivalent kinetic energy released by the wind turbines is equal to the sum of the kinetic energies of all wind turbines in the wind farm. The power generated during frequency modulation sum: (4) In the formula: The equivalent kinetic energy released by the wind turbine; the mechanical power of the wind turbine unit. With rotational speed The relationship between them is non-linear. Will follow Reduced and decreased, despite the initial speed of each fan Different, but In the interval Internal uniform change, equivalent wind turbine in steady state Captured mechanical power It can be approximated as all wind turbine units Mechanical power sum: (5) Due to the output power of the equalization machine for and The sum of these, therefore, under constrained consistency control, the equivalent model output power curve The curves are basically consistent with those calculated in the detailed model.

[0029] After performing single-unit equivalent calculations for wind farms that take into account traction control, the frequency response curves are calculated based on the single-unit equivalent model of the wind farm. The results are compared with the frequency response curves of the detailed model. The results show that the single-unit equivalent model of the wind farm that takes into account traction control has good accuracy in frequency calculation, proving that the single-unit equivalent model used in this application is applicable to frequency calculation.

[0030] The implementation process of the frequency control optimization problem of the wind-storage-load coordinated power system described in step (3) is as follows: Frequency security indicators To comprehensively evaluate the frequency security of the system; where: The initial rate of change of frequency reflects the speed of frequency change in the initial time period after the disturbance occurs. Due to measurement and action delay, the rate of change of frequency within 1 second after the disturbance is generally taken. Its calculation formula is: (6) In the formula: f 1 represents the system frequency 1 second after the disturbance occurs. f0 is the initial frequency. The detection interval is set to 1 second in this embodiment. , These are the lowest frequencies of the two frequency drops, respectively. The frequency peak during the two drops, The amplitude of the first oscillation of frequency during the dynamic process is defined as follows: [Specific value to be filled in] To suppress oscillation, [Specific value to be filled in] ... , To set the decimal; This is the steady-state frequency after the fault.

[0031] Control signal The expression is: (7) In the formula: The moment the fault begins. This marks the boundary between the frequency modulation phase and the recovery phase. Recorded as , This is the time when frequency modulation control exits; The value of determines the period of the sine function during the frequency modulation phase. The smaller, the better at the initial moment The faster the change; the more parameters A positive number is used to control the speed recovery rate. b The smaller the value, the slower the speed recovery; generally, a value of [value] can be taken as [value]. ; It is a decimal, used to ensure exist Continuity of time, Therefore, the parameters in the restraint signal b , It is known, and This requires further optimization.

[0032] In cases of severe faults, wind power frequency regulation needs to coordinate with other system control measures to ensure system frequency safety. Therefore, it is necessary to fully leverage the potential of wind power frequency regulation while ensuring frequency safety, aiming to reduce control costs, and to perform coordinated optimization of wind farm control signals and other control measures; assuming the energy storage output power after the disturbance is... Demand response power is Constraint signal depending on Given the possible values ​​of , the control variable to be optimized can be denoted as: The frequency control problem of wind-storage-load coordination can be described as follows: (8) In the formula: The economic cost of frequency control;c 1. c 2. Cost factors for energy storage and demand response respectively; The nonlinear dynamic mapping relationship between control measures and system frequency can be determined by solving a system of differential-algebraic equations; for Maximum value; This is the lowest frequency value; The lowest permissible frequency of the system in steady state; constraint signal parameters. There is a certain range of adjustment. , These are its upper and lower bounds, respectively. , These are the upper bounds of the energy storage output power and the demand response power after the disturbance, respectively.

[0033] The process of solving the optimal control strategy for wind power and energy storage based on the sensitivity method in step (4) is as follows: For the nonlinear dynamic optimization problem described by equation (8), the sensitivity-based approximate linearization method is used for iterative solution. The basic steps are as follows: Let the number of iterations Initial control variables Generate a random number within a specified range; Let the first During step iteration, control variables The corresponding system frequency response curve is calculated through numerical simulation. Calculate the security indicators for each frequency. ; Frequency safety indicators are obtained using the perturbation method. For control variables Sensitivity, in For example, calculate its effect on the restraint signal parameters. Energy storage output power after disturbance and demand response power The sensitivity, and convert the corresponding inequality in equation (8) into Similarly, by converting all other inequalities into linear inequalities, equation (8) is transformed into a linear programming problem. Solve the resulting linear programming problem to obtain the th... The change in the control variable of the step To optimize control variables Make corrections to obtain Generally, it is acceptable ; if , If no decimal is specified, the optimization ends, and the optimization result is output. Otherwise, (Jump to step 2) to continue optimization.

[0034] The sensitivity method in step 4 is applied to optimize the wind-storage-load coordinated frequency control strategy, and the drag signal parameters of the offshore wind farm are obtained. as well as and A single-machine equivalent model of the system was built in Matlab / Simulink software, and the corresponding system frequency response curve was obtained. Calculate various frequency security indicators and verify whether the set frequency security requirements are met under the given parameters.

[0035] Example 2 This embodiment provides a specific implementation example of applying the wind-storage-load coordinated frequency control method of the power system, which takes into account the restraint and control of deep-sea wind farms, as described above, to the connection of offshore wind farms to a 3-unit, 9-node system. For example... Figure 2 As shown, the offshore wind farm in the system consists of 6 doubly-fed wind turbines. - The system is connected to the grid at node 6 via a submarine AC cable, and energy storage and demand response are configured at nodes 7 and 9, respectively.

[0036] First, acquire power system data and wind turbine and traction controller parameters. The power system data includes synchronous generator and governor parameters, as well as energy storage system control parameters.

[0037] The parameters of the synchronous generator and speed governor in this embodiment are shown in Table 1: Table 1. Parameters of Synchronous Generator and Governor In this embodiment, the dynamic process of energy storage and demand response power adjustment is not considered, and it is assumed that their action times are 200 milliseconds and 90 seconds after the fault, respectively. The maximum adjustable power of energy storage and demand response is 40MW and 50MW, respectively. The cost factors of energy storage and demand response are also assumed. c 1. c 2 are 200,000 yuan / MW and 100,000 yuan / MW respectively; In this embodiment of the invention, the parameters of the doubly-fed wind turbine generator and its controller are shown in Table 2: Table 2 Parameters of Wind Turbine Unit and Controller Each wind turbine has a capacity of 25MVA, and the total capacity of the wind farm is 150MVA. Figure 2The transformer ratio for lines T1-T6 is 575V / 25kV, with a capacity of 30MVA and a short-circuit impedance of 0.04pu. The impedances of lines 10-17, 17-18, 18-19, 10-20, 20-21, and 21-22 are all 0.126 + 1.066. J Ohm.

[0038] An equivalent model of a single wind turbine generator, taking into account the wind farm's control and restraint, is established. In this embodiment, the equivalent wind turbine generator parameters are shown in Table 3. Table 3 Equivalent wind turbine parameters After performing single-unit equivalent modeling of the wind farm considering traction control, the frequency response curve is calculated based on the single-unit equivalent model of the wind farm. This model is then compared with the frequency response curve of the detailed model to verify the applicability of the single-unit equivalent model in frequency calculation. Taking the example system of the embodiment as an example, see attached... Figure 3 A comparison chart of wind power and frequency response curves calculated based on the equivalent model and the detailed model is presented. As can be seen from the chart, the calculation results of the single-unit equivalent model and the detailed model are basically consistent. However, due to a certain deviation in the wind power calculated by the single-unit equivalent model, the frequency response curve also shows a small deviation. The minimum frequency deviation at 40 seconds is approximately 0.03Hz. Overall, the accuracy of the single-unit equivalent model meets the requirements for frequency control decision-making.

[0039] The frequency control optimization problem of a wind-storage-load coordinated power system is solved using the sensitivity method to obtain the optimal control strategy for wind power and energy storage. In this embodiment, the system is equipped with energy storage with a rated capacity of 80 MWh and a rated power of 40 MW; the maximum adjustable power for demand response is 50 MW. At 10 s, the system load suddenly increases by 70 MW. [Further details are needed for accurate translation.] , The frequencies are 59.5Hz and 59.8Hz. Take 1Hz / s, , Take 40s and 25s respectively. Hz, The wind-storage-load coordinated frequency control strategy was optimized using the sensitivity method in step (4). The calculation converged after 5 iterations, taking approximately 800 seconds. The offshore wind farm restraint signal parameters in the obtained optimized control strategy are... It is 36.82s. , The respective capacities are 26.324MW and 8.954MW, with a control cost of 6,160,320 yuan; the system frequency response is as follows: Figure 5 As shown by the solid line in the figure, The frequency was 0.112 Hz / s, with the two lowest frequency values ​​being 59.679 Hz and 59.501 Hz, respectively. and The difference between them is 0.03Hz, which meets the set frequency safety requirements.

[0040] To analyze the impact of changes in the confinement signal parameters on the frequency response curve, and to maintain... and Unchanged, take respectively Simulations were performed for 28s and 40s, respectively. The corresponding frequency response curves are attached. Figure 5 As shown in Table 4, its frequency security indicators are as follows.

[0041] Table 4 System frequency security indicators under different restraint signals As can be seen from Table 4, When the energy is relatively small, the kinetic energy is released more quickly, therefore Smaller Larger, but lowest frequency point Lower. With The increase, Gradually increase Decrease, oscillation amplitude It increases accordingly, but There has been some improvement. This shows that... At lower levels, it can improve short-term power support, but it is prone to causing... Exceeding the limit requires a larger [scale / capacity]. To ensure Do not exceed the limits; When it is large, it can be improved But it will also increase and oscillation amplitude. Increase This can comprehensively improve the frequency security of the system, but the control cost will increase accordingly. Therefore, this invention formulates a frequency control strategy by... , and Collaborative optimization enables rapid recovery of wind power systems under severe fault conditions.

[0042] Example 3 As a second aspect of the present invention, this application also provides an electronic device, comprising: one or more processors; a memory for storing one or more programs; and, when the one or more programs are executed by the one or more processors, causing the one or more processors to implement the wind-storage-load coordinated control method as described above, which takes into account the restraint control of deep-sea wind farms. In addition to the processors, memory, and interfaces described above, any data processing device in the embodiments may also include other hardware depending on the actual function of the data processing device, which will not be elaborated further.

[0043] Example 4 As a third aspect of the present invention, this application also provides a computer-readable storage medium storing computer instructions thereon, which, when executed by a processor, implement the wind-storage-load coordinated control method as described above, taking into account the control of deep-sea wind farms. The computer-readable storage medium can be an internal storage unit of any data processing device as described in any of the foregoing embodiments, such as a hard disk or memory. The computer-readable storage medium can also be an external storage device, such as a plug-in hard disk, smart media card (SMC), SD card, flash card, etc., equipped on the device. Furthermore, the computer-readable storage medium can include both internal storage units of any data processing device and external storage devices. The computer-readable storage medium is used to store the computer program and other programs and data required by the data processing device, and can also be used to temporarily store data that has been output or will be output.

[0044] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A wind-storage-load coordinated control method considering the restraint control of deep-sea wind farms, characterized in that, The method steps include: Acquire power system data and parameters of wind turbines and traction controllers; An equivalent model of a single wind turbine, taking into account the wind farm's control and restraint systems, is established as follows: The equivalent capacity of a wind turbine is equal to the sum of the capacities of all wind turbine units within the wind farm; Mechanical power captured by an equivalent wind turbine in steady state before disturbance The output power at the grid connection point of the wind farm is equal to With losses within the wind farm The sum; based on the maximum power point tracking curve of the wind turbine, calculate the corresponding equivalent wind turbine speed. And based on the equivalent wind turbine speed and maximum tip speed ratio Find the equivalent wind turbine unit wind speed The connection impedance between the equivalent wind turbine and the common coupling point is set as follows: In the formula, n lk For the line l-k Number of upstream wind turbine units For the power lines within the wind farm l-k The impedance between them n w This represents the total number of wind turbines in the wind farm. During frequency regulation, the kinetic energy released by the equivalent wind turbine is equal to the additional power generated by each wind turbine in the wind farm during the frequency regulation process. sum: The wind turbine i The power generated during frequency modulation It is expressed as follows: In the formula, Signal control for wind farms; For wind turbine consistent state variables; For communication weight; Indicates whether the wind turbine receives a restraint signal; These represent the proportional coefficient and integral coefficient of the control system, respectively. This represents the set of wind turbine unit numbers. This represents the total number of wind turbines in the wind farm. After frequency regulation and steady state, the equivalent mechanical power captured by the wind turbine Approximately the mechanical power of all wind turbine units sum; Under severe fault conditions, a wind-storage-load coordinated power system frequency control optimization problem is constructed with the goal of minimizing the economic cost of frequency control. The frequency control optimization problem uses the energy storage output power after disturbance, the demand response power, and the frequency regulation phase duration of the restraint signal as control variables. The optimal control strategy for wind power and energy storage is obtained by solving the frequency control optimization problem of the power system based on the sensitivity method.

2. The wind-storage-load coordinated control method considering the restraint control of deep-sea wind farms according to claim 1, characterized in that, The power system data includes: Synchronous generator capacity Inertial time constant and damping coefficient For steam turbine generators, governor parameters include governor gain. reheater coefficient Reheater time constant and the governor time constant For hydro-generators, governor parameters include gain. Water hammer effect time constant and the time constant of the turbine governor ; Energy storage system control parameters, including maximum adjustable power. Cost factor c 1 and response time t ES ; Demand response control parameters, including maximum adjustable power Cost factor c 2 and response time t dr .

3. The wind-storage-load coordinated control method considering the restraint control of deep-sea wind farms according to claim 1, characterized in that, The parameters of the wind turbine and traction controller include: Wind farm wiring l-k impedance between and wind turbines capacity Inertial time constant and generator terminal transformer capacity S Ti and short-circuit impedance Z Ti ; Obtain the wind farm's traction control topology and traction controller parameters, including proportional and integral coefficients. .

4. The wind-storage-load coordinated control method considering the restraint control of deep-sea wind farms according to claim 1, characterized in that, The restraining signal The expression is: In the formula, The moment the fault begins. This marks the boundary between the frequency modulation phase and the recovery phase. Recorded as , This refers to the time when the frequency modulation control exits; parameters A positive number is used to control the speed recovery rate. b The smaller the value, the slower the speed recovery; It is a decimal, used to ensure exist Continuity of time.

5. The wind-storage-load coordinated control method considering the restraint control of deep-sea wind farms according to claim 1, characterized in that, The frequency control optimization problem of constructing a wind-storage-load coordinated power system adopts frequency security indicators. To comprehensively evaluate the frequency security of the system, specifically including: Initial rate of change of frequency The frequency change rate within a set time after the disturbance is taken to reflect the frequency change rate in the initial time period after the disturbance occurs. The lowest frequency of the two frequency drops , ; Peak frequency during the two drops , The amplitude of the first oscillation of frequency during the dynamic process ; steady-state frequency after fault .

6. A wind-storage-load coordinated control method considering the restraint control of deep-sea wind farms according to claim 5, characterized in that, The aforementioned wind-storage-load coordinated power system frequency control optimization problem aims to minimize the economic cost of frequency control and the output power of energy storage after disturbance. Demand response power and restraint signals Frequency modulation phase duration For the control variables to be optimized The description is as follows: In the formula, The economic cost of frequency control; c 1. c 2. Cost factors for energy storage and demand response respectively; This represents the nonlinear dynamic mapping relationship between control measures and system frequencies; The initial rate of change of frequency Maximum value; To set the decimal; This is the lowest frequency value; This is the lowest frequency allowed by the system in steady state. , These are the parameters of the restraint signal. The upper and lower bounds of the adjustment; , These are the upper bounds of the energy storage output power and the demand response power after the disturbance, respectively.

7. A wind-storage-load coordinated control method considering the restraint control of deep-sea wind farms according to claim 6, characterized in that, The frequency control optimization problem of the wind-storage-load coordinated power system is solved iteratively using a sensitivity-based approximate linearization method, with the following steps: Randomly initialize control variables ; The corresponding system frequency response curve is calculated through numerical simulation. And calculate the security indicators for each frequency; Frequency safety indicators are obtained using the perturbation method. For control variables The sensitivity of the frequency control optimization problem is transformed into a linear programming problem by converting all safety index constraint inequalities into linear inequalities. Solve the resulting linear programming problem, obtain the changes in the control variables, and determine the control variables to be optimized. Make corrections; Repeat the optimization until the change in the control variable is less than the set threshold.

8. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the wind-storage-load coordinated control method as described in any one of claims 1-7, which takes into account the restraint control of deep-sea wind farms.

9. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the wind-storage-load coordinated control method as described in any one of claims 1-7, which considers the restraint control of deep-sea wind farms.

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