Adaptive model predictive control method and system for primary frequency modulation of energy storage power station

Abstract

The application discloses a self-adaptive model predictive control method and system for primary frequency modulation of an energy storage power station, relates to the technical field of electric power control, and solves the problem that energy storage converters cannot be subjected to efficient primary frequency modulation. The method comprises the following steps: calibrating the measurement accuracy of a primary frequency modulation device; constructing a self-adaptive model workflow and obtaining abnormal grid-connected points in a power grid through self-adaptive model output; calculating active power adjustment or reactive power adjustment according to the output data of the self-adaptive model; predicting the power balance state of different grid-connected points in the power grid to obtain risk grid-connected points; and when there are abnormal grid-connected points or risk grid-connected points in the power grid, corresponding control is performed on the abnormal grid-connected points or the risk grid-connected points. The application realizes efficient primary frequency modulation of energy storage converters.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of power control, and particularly relates to an adaptive model predictive control method and system for primary frequency modulation of an energy storage power station. BACKGROUND

[0002] An energy storage power station is a device capable of balancing the mismatch between power system load and power supply. In a power system, power demand and supply are unstable, especially during peak periods, and a sharp increase in power demand will cause excessive stress on the power grid and even cause local power outages. The energy storage power station can store power and release the stored power to meet the requirements of the power grid when needed, and can be recharged during low peak periods. As an important part of modern power systems, the frequency modulation function of the energy storage power station is crucial to maintaining the stability of the power grid, and the primary frequency modulation is one of the key links of the frequency modulation function of the energy storage power station.

[0003] In the prior art, the predictive control method for primary frequency modulation of the energy storage power station mostly only supports the electrical quantity collection function of a small number of grid connection points, and it is difficult to reflect the real-time frequency state and real-time voltage state of the power grid from different grid connection points. At the same time, for the adjustment of the energy storage converter in the energy storage power station, the prior art mostly only adjusts individual energy storage converters, and cannot realize power coordinated distribution of the energy storage converters through droop control.

[0004] Therefore, the application provides an adaptive model predictive control method and system for primary frequency modulation of an energy storage power station. SUMMARY

[0005] The application aims to provide an adaptive model predictive control method and system for primary frequency modulation of an energy storage power station to solve the problem of inefficient primary frequency modulation of the energy storage converter in the background technology.

[0006] The application can be achieved by the following technical solutions.

[0007] In a first aspect, the application provides an adaptive model predictive control method for primary frequency modulation of an energy storage power station, and the method comprises the following steps.

[0008] Step S1: calibrating the measurement accuracy of the primary frequency modulation device;

[0009] Step S2: constructing a workflow of an adaptive model, and obtaining abnormal grid connection points in the power grid through output of the adaptive model;

[0010] Step S3: calculating the active power adjustment amount or the reactive power adjustment amount according to the output data of the adaptive model;

[0011] Step S4: predicting the power balance state of different grid connection points in the power grid to obtain a risk grid connection point;

[0012] Step S5, when there is an abnormal grid connection point or a risk grid connection point in the power grid, the abnormal grid connection point or the risk grid connection point is controlled accordingly.

[0013] Further, the calibration process in step S1 includes the following sub-steps:

[0014] Step S11, the primary frequency modulation device is connected to the three-phase test circuit, an initial current is input to the three-phase test circuit, and the input initial current is recorded as the input current value of different phases;

[0015] Step S12, the actual current values of different phases displayed on the primary frequency modulation device are read, and the current error rates of different phases in the primary frequency modulation device are obtained by subtracting the input current value from the actual current value and dividing by the input current value of the corresponding phase;

[0016] Step S13, the current error rates of different phases are compared with the current error rate interval;

[0017] If the current error rates of all phases belong to the current error rate interval, the input current value is increased in steps, and steps S12 and S13 are repeated until the input current value reaches the current measurement range of the primary frequency modulation device;

[0018] If the current error rate of any phase does not belong to the current error rate interval, the primary frequency modulation device is calibrated until the current error rate of the corresponding phase belongs to the current error rate interval;

[0019] Step S14, similarly, the initial voltage is input to the three-phase test circuit, and the voltage error rates of different phases in the primary frequency modulation device are calculated by repeating step S12, and the voltage error rates of different phases are compared with the voltage error rate interval;

[0020] If the voltage error rates of all phases belong to the voltage error rate interval, the input voltage value is increased in steps, and steps S12 and S13 are repeated until the input voltage value reaches the voltage measurement range of the primary frequency modulation device;

[0021] If the voltage error rate of any phase does not belong to the voltage error rate interval, the primary frequency modulation device is calibrated until the voltage error rate of the corresponding phase belongs to the voltage error rate interval.

[0022] Further, the construction process in step S2 includes the following sub-steps:

[0023] Step S21, first, the real-time frequency and real-time three-phase voltage of different grid connection points at different time nodes are collected and taken as the input value of the adaptive model;

[0024] Step S22, when the input value enters the adaptive model, the real-time frequency of different grid-connected points in the current time node power grid is compared with the standard frequency interval, and the real-time three-phase voltage of different grid-connected points in the current time node power grid is compared with the standard voltage interval;

[0025] If the real-time frequency of any grid-connected point in the current time node power grid does not belong to the standard frequency interval, but the real-time three-phase voltage of all grid-connected points belongs to the standard voltage interval, the corresponding grid-connected point is recorded as a frequency abnormal grid-connected point and step S23 is entered;

[0026] If the real-time frequency of all grid-connected points in the current time node power grid belongs to the standard frequency, but the real-time three-phase voltage of any grid-connected point does not belong to the standard voltage interval, the corresponding grid-connected point is recorded as a voltage abnormal grid-connected point and step S23 is entered;

[0027] If the real-time frequency of all grid-connected points in the current time node power grid does not belong to the standard frequency interval, and the real-time three-phase voltage of all grid-connected points does not belong to the standard voltage interval, a maintenance warning is immediately issued;

[0028] If the real-time frequency of all grid-connected points in the current time node power grid belongs to the standard frequency interval, and the real-time three-phase voltage of all grid-connected points belongs to the standard voltage interval, step S4 is entered;

[0029] Step S23, the frequency abnormal grid-connected point and the voltage abnormal grid-connected point are recorded as abnormal grid-connected points in the power grid, and the abnormal grid-connected point is recorded as the output data of the adaptive model;

[0030] Step S24, steps S21-S23 are recorded as the workflow of the adaptive model.

[0031] Further, the calculation process in step S3 includes the following sub-steps:

[0032] Step S31, the output data of the adaptive model is input to the primary frequency regulation device;

[0033] Step S32, for the frequency abnormal grid-connected point, the primary frequency regulation device calculates the active power adjustment amount of the energy storage power station through the AGC unit;

[0034] Step S33, for the voltage abnormal grid-connected point, the primary frequency regulation device calculates the reactive power adjustment amount of the energy storage power station through the AVC unit.

[0035] Further, the calculation process in step S32 includes the following sub-steps:

[0036] Step S321, obtaining the rated frequency, real-time frequency of the frequency abnormal grid-connected point, rated active power of different energy storage converters and maximum frequency deviation allowed by the frequency abnormal grid-connected point in the power grid;

[0037] Step S322, obtaining the frequency difference of the frequency abnormal grid-connected point in the power grid by subtracting the rated frequency from the real-time frequency;

[0038] Step S323, obtaining the droop coefficient of different energy storage converters by dividing the maximum frequency deviation by the rated active power of different energy storage power stations, and obtaining the reciprocal of the total droop coefficient of the energy storage power station by summing the reciprocals of the droop coefficients of different energy storage converters;

[0039] Step S324, calculating the active power adjustment amount of the energy storage power station.

[0040] Further, the calculation process in step S33 includes the following sub-steps:

[0041] Step S331, obtaining the rated voltage, real-time voltage of the voltage abnormal grid-connected point, rated reactive power of different energy storage converters and maximum voltage deviation allowed by the voltage abnormal grid-connected point in the power grid;

[0042] Step S332, obtaining the voltage difference of the voltage abnormal grid-connected point in the power grid by subtracting the rated voltage from the real-time voltage;

[0043] Step S333, obtaining the droop coefficient of different energy storage converters by dividing the maximum voltage deviation by the rated reactive power of different energy storage power stations, and obtaining the reciprocal of the total droop coefficient of the energy storage power station by summing the reciprocals of the droop coefficients of different energy storage converters;

[0044] Step S334, calculating the reactive power adjustment amount of the energy storage power station.

[0045] Further, the prediction process in step S4 includes the following sub-steps:

[0046] Step S41, collecting the load three-phase voltage, load three-phase current and real-time phase difference of the load end of different grid-connected points in the power grid at different time nodes, and recording the load three-phase voltage, load three-phase current and real-time phase difference as load electrical data;

[0047] Step S42, calculating the load line voltage of the grid-connected point load end in the power grid, and recording the load three-phase current as the load line current of the grid-connected point load end in the power grid;

[0048] Step S43, calculating the load active power of the grid-connected point load end in the power grid at different time nodes;

[0049] Similarly, repeat steps S41-S42 to collect the load electrical data of the voltage abnormality grid-connected point load end, and calculate the load reactive power of the grid-connected point load end at different time nodes;

[0050] Step S44, repeat steps S41-S43 to calculate the generation active power and generation reactive power of the grid-connected point generation end in the power grid at different time nodes;

[0051] Step S45, subtract the load active power from the generation active power of the grid-connected point in the current time node of the power grid to obtain the active power difference value of the grid-connected point in the current time node of the power grid;

[0052] Similarly, subtract the load reactive power from the generation reactive power of the grid-connected point in the current time node of the power grid to obtain the reactive power difference value of the grid-connected point in the current time node of the power grid;

[0053] Similarly, the active power difference value and the reactive power difference value of the grid-connected point in the power grid at different time nodes are calculated;

[0054] Step S46, analyze the active power difference value and the reactive power difference value of the grid-connected point in the power grid at different time nodes;

[0055] Step S47, record the frequency risk grid-connected point and the voltage risk grid-connected point as risk grid-connected points.

[0056] Further, the analysis process in step S46 includes the following sub-steps:

[0057] Step S461, obtain the maximum active power difference value and the maximum reactive power difference value allowed by the grid-connected point in the power grid;

[0058] Step S462, take half of the maximum active power difference value as the active power difference early warning value, and take half of the maximum reactive power difference value as the reactive power difference early warning value;

[0059] Step S463, record the time node corresponding to the active power difference value greater than or equal to the active power difference early warning value as the first time node, and record the time node corresponding to the active power difference value less than the active power difference early warning value as the second time node;

[0060] Similarly, record the time node corresponding to the reactive power difference value greater than or equal to the reactive power difference early warning value as the third time node, and record the time node corresponding to the reactive power difference value less than the reactive power difference early warning value as the fourth time node;

[0061] Step S464, count the number of first time nodes and the number of second time nodes within a fixed time period, and compare the number of first time nodes and the number of second time nodes within the fixed time period;

[0062] If the number of the first time nodes is greater than or equal to the number of the second time nodes within the fixed time length, the corresponding grid-connected point is recorded as a frequency risk grid-connected point;

[0063] If the number of the first time nodes is less than the number of the second time nodes within the fixed time length, no operation is performed;

[0064] Similarly, the number of the third time nodes and the number of the fourth time nodes within the fixed time length are counted and compared;

[0065] If the number of the third time nodes is greater than or equal to the number of the fourth time nodes within the fixed time length, the corresponding grid-connected point is recorded as a voltage risk grid-connected point;

[0066] If the number of the third time nodes is less than the number of the fourth time nodes within the fixed time length, no operation is performed.

[0067] Further, the control process in the step S5 includes the following sub-steps:

[0068] Step S51, when the grid-connected point in the power grid is a frequency abnormal grid-connected point, the primary frequency modulation device controls the frequency abnormal grid-connected point;

[0069] The control process in the step S51 includes the following sub-steps:

[0070] Step S511, the rated active power of different energy storage converters is obtained, and the rated active power of different energy storage converters is summed to obtain the total rated active power of the energy storage power station;

[0071] Step S512, the rated active power of different energy storage converters is divided by the total rated active power to obtain the rated active power proportion of different energy storage converters;

[0072] Step S513, the rated active power proportion is multiplied by the active power adjustment amount to obtain the individual active adjustment amount of different energy storage converters;

[0073] Step S514, the generated active power of the frequency abnormal grid-connected point is compared with the load active power;

[0074] If the generated active power of the frequency abnormal grid-connected point in the power grid is greater than the load active power, different energy storage converters are charged, and the charging power is the individual active adjustment amount corresponding to different energy storage converters;

[0075] If the generated active power of the frequency abnormal grid-connected point in the power grid is less than the load active power, different energy storage converters are discharged, and the discharging power is the individual active adjustment amount corresponding to different energy storage converters;

[0076] Step S52, when the grid point in the power grid is a voltage abnormal grid point, the primary frequency regulation device controls the voltage abnormal grid point;

[0077] The control process in step S52 includes the following sub-steps:

[0078] Step S521, obtain the rated reactive power of different energy storage converters, and sum the rated reactive power of different energy storage converters to obtain the total rated reactive power of the energy storage power station;

[0079] Step S522, divide the rated reactive power of different energy storage converters by the total rated reactive power to obtain the proportion of the rated reactive power of different energy storage converters;

[0080] Step S523, multiply the proportion of the rated reactive power by the reactive power adjustment amount to obtain the individual reactive adjustment amount of different energy storage converters;

[0081] Step S524, compare the generated reactive power and the load reactive power of the voltage abnormal grid point;

[0082] If the generated reactive power of the voltage abnormal grid point in the power grid is greater than the load reactive power, control the energy storage converter to absorb reactive power, and the absorption amount of different energy storage converters is the corresponding individual reactive adjustment amount;

[0083] If the generated active power of the frequency abnormal grid point in the power grid is less than the load active power, control the energy storage converter to output reactive power, and the output amount of different energy storage converters is the corresponding individual reactive adjustment amount;

[0084] Step S53, when the grid point in the power grid is a risk grid point, the primary frequency regulation device continuously monitors the risk grid point.

[0085] In a second aspect, the adaptive model predictive control system of the primary frequency regulation of the energy storage power station comprises:

[0086] A data acquisition module for acquiring electrical data of different grid points in the power grid and sending the data to a data calibration module;

[0087] A data calibration module for calibrating the measurement accuracy of the primary frequency regulation device;

[0088] A data analysis module for constructing the workflow of the adaptive model and analyzing the state of the grid points in the power grid, obtaining a normal state signal, a frequency abnormal grid point or a voltage abnormal grid point, sending the normal state signal to a power prediction module, and sending the frequency abnormal grid point or the voltage abnormal grid point to a data calculation module;

[0089] A data calculation module is configured to calculate active power adjustment or reactive power adjustment of the energy storage power station and send the calculation result to the intelligent control module.

[0090] A power prediction module is configured to predict power of the grid-connected point in the power grid after receiving the normal state signal, generate a power abnormal signal, and send the signal to the intelligent control module.

[0091] An intelligent control module is configured to control the energy storage converter in the energy storage power station.

[0092] In summary, the present application has the following advantages:

[0093] 1. The present application firstly calibrates the measurement accuracy of the primary frequency modulation device, then constructs a workflow of the adaptive model, and outputs the frequency abnormal grid-connected point or voltage abnormal grid-connected point in the power grid through the adaptive model, so as to realize accurate measurement of the primary frequency modulation device and preliminarily analyze different abnormal grid-connected points in the power grid.

[0094] 2. The present application further calculates the active power adjustment or reactive power adjustment according to the output data of the adaptive model, and predicts the power balance state of the normal grid-connected point in the power grid to obtain the risk grid-connected point, so as to realize calculation of the power adjustment of the abnormal grid-connected point and prediction of the power balance state of the normal grid-connected point.

[0095] 3. The present application finally distributes the power adjustment to different energy storage converters in the energy storage power station, so as to control different abnormal grid-connected points in the power grid, and realize efficient primary frequency modulation of the energy storage converter. BRIEF DESCRIPTION OF DRAWINGS

[0096] For the convenience of those skilled in the art, the present application will be further described below with reference to the accompanying drawings.

[0097] Figure 1 The present application is a method flowchart.

[0098] Figure 2 The present application is a whole logic block diagram.

[0099] Figure 3 The present application is a whole system block diagram. DETAILED DESCRIPTION

[0100] The technical solutions of the present application will be described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0101] Embodiment one: please refer to Figure 1 and Figure 2 As shown in the figure, the technical scheme provided by the application is a self-adaptive model prediction control method for primary frequency modulation of an energy storage power station. The method is suitable for analyzing a grid connection point in a power grid by a primary frequency modulation device, thereby controlling the energy storage power station and an energy storage converter in the energy storage power station. The method comprises the following steps:

[0102] Step S1, calibrating the measurement accuracy of the primary frequency modulation device;

[0103] In this embodiment, the calibration process comprises the following sub-steps:

[0104] Step S11, connecting the primary frequency modulation device to a three-phase test circuit, inputting an initial current to the three-phase test circuit, and recording the input initial current as the input current value of different phases;

[0105] Step S12, reading the actual current values of different phases displayed on the primary frequency modulation device, subtracting the input current value from the actual current value, and dividing the result by the input current value of the corresponding phase to obtain the current error rate of different phases in the primary frequency modulation device;

[0106] Step S13, comparing the current error rates of different phases with the current error rate interval;

[0107] If the current error rates of all phases belong to the current error rate interval, then the input current value is increased in steps, and steps S12 and S13 are repeated until the input current value reaches the current measurement range of the primary frequency modulation device;

[0108] If the current error rate of any phase does not belong to the current error rate interval, then the primary frequency modulation device is calibrated until the current error rate of the corresponding phase belongs to the current error rate interval;

[0109] In the specific implementation process, the initial current can be 1A, the input current value can be increased by 1A each time, and the measurement range is the maximum value of the measurable current of the primary frequency modulation device. In this embodiment, the current measurement range can be 5A, and the current error rate interval can be [-0.2%, 0.2%];

[0110] Step S14, similarly, input the initial voltage to the three-phase test circuit, and repeat step S12 to calculate the voltage error rate of different phases in the primary frequency modulation device, and compare the voltage error rates of different phases with the voltage error rate interval;

[0111] If the voltage error rates of all phases belong to the voltage error rate interval, then the input voltage value is increased in steps, and steps S12 and S13 are repeated until the input voltage value reaches the voltage measurement range of the primary frequency modulation device;

[0112] If the voltage error rate of any phase does not belong to the voltage error rate interval, calibrate the primary frequency modulation device until the voltage error rate of the corresponding phase belongs to the voltage error rate interval;

[0113] In the embodiment, the voltage error rate interval can be [-0.2%, 0.2%], and the voltage measurement range can be 57.735V; in the specific implementation process, the frequency error value of the primary frequency modulation device also needs to be compared with the frequency error value interval, and in the embodiment, the frequency error value interval can be [-0.003, 0.003], the comparison process is similar to the current-voltage comparison process, which will not be described here.

[0114] Step S2, constructing a workflow of an adaptive model, and outputting abnormal grid-connected points in the power grid through the adaptive model;

[0115] In the embodiment, the construction process in the step S2 includes the following sub-steps:

[0116] Step S21, first, collecting real-time frequencies and real-time three-phase voltages of different grid-connected points in the power grid at different time nodes, and taking them as input values of the adaptive model;

[0117] Step S22, when the input values enter the adaptive model, comparing the real-time frequencies of different grid-connected points in the power grid at the current time node with the standard frequency interval, and comparing the real-time three-phase voltages of different grid-connected points in the power grid at the current time node with the standard voltage interval;

[0118] If the real-time frequency of any grid-connected point in the power grid at the current time node does not belong to the standard frequency interval but the real-time three-phase voltages of all grid-connected points belong to the standard voltage interval, the corresponding grid-connected point is recorded as a frequency abnormal grid-connected point and enters step S23;

[0119] If the real-time frequencies of all grid-connected points in the power grid at the current time node belong to the standard frequency interval but the real-time three-phase voltage of any grid-connected point does not belong to the standard voltage interval, the corresponding grid-connected point is recorded as a voltage abnormal grid-connected point and enters step S23;

[0120] If the real-time frequencies of all grid-connected points in the power grid at the current time node do not belong to the standard frequency interval and the real-time three-phase voltages of all grid-connected points do not belong to the standard voltage interval, a maintenance warning is immediately issued;

[0121] If the real-time frequencies of all grid-connected points in the power grid at the current time node belong to the standard frequency interval and the real-time three-phase voltages of all grid-connected points belong to the standard voltage interval, step S4 is entered;

[0122] Step S23, record the frequency abnormal grid connection point and the voltage abnormal grid connection point as the abnormal grid connection points in the power grid, and record the abnormal grid connection points as the output data of the adaptive model;

[0123] Step S24, record steps S21-S23 as the workflow of the adaptive model;

[0124] It should be explained that the adaptive model can be realized by a primary frequency regulation device.

[0125] Step S3, calculate the active power adjustment amount or the reactive power adjustment amount according to the output data of the adaptive model;

[0126] In this embodiment, the calculation process in step S3 includes the following sub-steps:

[0127] Step S31, input the output data of the adaptive model into the primary frequency regulation device;

[0128] In this embodiment, the output data can be connected to the primary frequency regulation device through GOOSE communication;

[0129] Step S32, for the frequency abnormal grid connection point, the primary frequency regulation device calculates the active power adjustment amount of the energy storage power station through the AGC unit;

[0130] Specifically, the calculation process in step S32 includes the following sub-steps:

[0131] Step S321, obtain the rated frequency f0 of the frequency abnormal grid connection point in the power grid, the real-time frequency f1, the rated active power of different energy storage converters, and the maximum frequency deviation allowed by the frequency abnormal grid connection point in the power grid;

[0132] Step S322, subtract the rated frequency from the real-time frequency to obtain the frequency difference △f of the frequency abnormal grid connection point in the power grid;

[0133] Step S323, divide the maximum frequency deviation by the rated active power of different energy storage power stations to obtain the droop coefficient of different energy storage converters, and add the reciprocals of the droop coefficients of different energy storage converters to obtain the reciprocal K1 of the total droop coefficient of the energy storage power station;

[0134] In the specific implementation process, the rated frequency f0 of the power grid is 50Hz, and the rated active power of the energy storage converter can be obtained from the technical specifications of the energy storage power station;

[0135] Step S324, calculate the active power adjustment amount △P of the energy storage power station by the formula △P=|△f×(-K1)|;

[0136] Step S33, for the voltage abnormal grid connection point, the primary frequency regulation device calculates the reactive power adjustment amount of the energy storage power station through the AVC unit;

[0137] In the embodiment, the calculation process in the step S33 comprises the following sub-steps:

[0138] In the step S331, the rated voltage U0, the real-time voltage U1 of the voltage abnormal grid-connection point in the power grid, the rated reactive power of the different energy storage converters and the maximum voltage deviation allowed by the voltage abnormal grid-connection point in the power grid are obtained.

[0139] In the step S332, the voltage difference △U of the voltage abnormal grid-connection point in the power grid is obtained by subtracting the rated voltage from the real-time voltage.

[0140] In the step S333, the droop coefficient of the different energy storage converters is obtained by dividing the maximum voltage deviation by the rated reactive power of the different energy storage stations, and the reciprocal of the total droop coefficient of the energy storage stations K2 is obtained by summing the reciprocals of the droop coefficients of the different energy storage converters.

[0141] In the implementation process, the rated voltage and the maximum voltage deviation allowed by the power grid can be obtained according to the grid level of the power grid, and the rated reactive power of the energy storage converter can be obtained from the technical specifications of the energy storage station.

[0142] In the step S334, the reactive power adjustment amount △Q of the energy storage station is obtained by the formula △Q=|△U×(-K2)|.

[0143] It should be explained that the AGC unit and the AVC unit are calculation units inside the primary frequency modulation device.

[0144] In the step S4, the power balance state of the different grid-connection points in the power grid is predicted, and the risk grid-connection point is obtained.

[0145] In the embodiment, the prediction process in the step S4 comprises the following sub-steps:

[0146] In the step S41, the load three-phase voltage U, the load three-phase current and the real-time phase difference XW of the load end of the different grid-connection points in the power grid at different time nodes are collected, and the load three-phase voltage, the load three-phase current and the real-time phase difference are recorded as the load electrical data.

[0147] In the embodiment, taking the three-phase balanced circuit as an example, the three-phase balanced circuits are connected in star, the load three-phase voltage is the phase voltage, the load three-phase current is the phase current, and the real-time phase difference is the phase difference between the load three-phase voltage and the load three-phase current.

[0148] In the step S42, the load line voltage UX of the load end of the grid-connection point in the power grid is obtained by the formula In the step S42, the load line voltage UX of the load end of the grid-connection point in the power grid is obtained by the formula

[0149] Step S43, the load active power YG of the grid-connected point load end in the power grid at different time nodes is calculated by the formula

[0150] Similarly, steps S41-S42 are repeated to collect the load electrical data of the voltage abnormal grid-connected point load end in the power grid, and the load reactive power WG of the grid-connected point load end in the power grid at different time nodes is calculated by the formula

[0151] Step S44, steps S41-S43 are repeated to calculate the power generation active power and power generation reactive power of the grid-connected point power generation end in the power grid at different time nodes;

[0152] Step S45, the absolute value of the difference between the power generation active power and the load active power of the grid-connected point in the power grid at the current time node is obtained as the active power difference value of the grid-connected point in the power grid at the current time node;

[0153] Similarly, the absolute value of the difference between the power generation reactive power and the load reactive power of the grid-connected point in the power grid at the current time node is obtained as the reactive power difference value of the grid-connected point in the power grid at the current time node;

[0154] Similarly, the active power difference value and the reactive power difference value of the grid-connected point in the power grid at different time nodes are calculated;

[0155] Step S46, the active power difference value and the reactive power difference value of the grid-connected point in the power grid at different time nodes are analyzed;

[0156] In this embodiment, the analysis process in step S46 includes the following sub-steps:

[0157] Step S461, the maximum active power difference value and the maximum reactive power difference value allowed by the grid-connected point in the power grid are obtained;

[0158] In the specific implementation process, the maximum active power difference value and the maximum reactive power difference value are preset values;

[0159] Step S462, half of the maximum active power difference value is taken as the active power difference early warning value, and half of the maximum reactive power difference value is taken as the reactive power difference early warning value;

[0160] Step S463, the time node corresponding to the active power difference value greater than or equal to the active power difference early warning value is recorded as the first time node, and the time node corresponding to the active power difference value less than the active power difference early warning value is recorded as the second time node;

[0161] ​​Similarly, the time node corresponding to the reactive power difference value greater than or equal to the reactive power difference early warning value is recorded as a third time node, and the time node corresponding to the reactive power difference value less than the reactive power difference early warning value is recorded as a fourth time node;

[0162] It should be explained that the first time node, the second time node, the third time node and the fourth time node have no size relationship, and the first, the second, the third and the fourth are only the name difference of the time node;

[0163] Step S464, the number of first time nodes and the number of second time nodes in a fixed time period are counted, and the number of first time nodes and the number of second time nodes in a fixed time period are compared;

[0164] If the number of first time nodes in a fixed time period is greater than or equal to the number of second time nodes, it means that there is a risk of active power imbalance corresponding to the grid connection point, and then the corresponding grid connection point is recorded as a frequency risk grid connection point;

[0165] If the number of first time nodes in a fixed time period is less than the number of second time nodes, no operation is performed;

[0166] Similarly, the number of third time nodes and the number of fourth time nodes in a fixed time period are counted, and the number of third time nodes and the number of fourth time nodes in a fixed time period are compared;

[0167] If the number of third time nodes in a fixed time period is greater than or equal to the number of fourth time nodes, it means that there is a risk of reactive power imbalance corresponding to the grid connection point, and then the corresponding grid connection point is recorded as a voltage risk grid connection point;

[0168] If the number of third time nodes in a fixed time period is less than the number of fourth time nodes, no operation is performed;

[0169] Step S47, the frequency risk grid connection point and the voltage risk grid connection point are recorded as a risk grid connection point.

[0170] Step S5, when there is an abnormal grid connection point or a risk grid connection point in the power grid, the abnormal grid connection point or the risk grid connection point is controlled;

[0171] In this embodiment, the control process in the step S5 includes the following sub-steps:

[0172] Step S51, when the grid connection point in the power grid is a frequency abnormal grid connection point, a primary frequency modulation device controls the frequency abnormal grid connection point;

[0173] In this embodiment, the control process in the step S51 includes the following sub-steps:

[0174] Step S511, the rated active power of different energy storage converters is obtained, and the rated active power of different energy storage converters is added to obtain the total rated active power of the energy storage power station;

[0175] Step S512, the rated active power of different energy storage converters is divided by the total rated active power to obtain the proportion of the rated active power of different energy storage converters;

[0176] Step S513, the proportion of the rated active power is multiplied by the active power adjustment amount to obtain the individual active adjustment amount of different energy storage converters;

[0177] Step S514, the generated active power of the frequency abnormal grid-connected point is compared with the load active power;

[0178] If the generated active power of the frequency abnormal grid-connected point in the power grid is greater than the load active power, the different energy storage converters are charged, and the charging power is the individual active adjustment amount corresponding to the different energy storage converters;

[0179] If the generated active power of the frequency abnormal grid-connected point in the power grid is less than the load active power, the different energy storage converters are discharged, and the discharge power is the individual active adjustment amount corresponding to the different energy storage converters;

[0180] Step S52, when the grid-connected point in the power grid is a voltage abnormal grid-connected point, the primary frequency modulation device controls the voltage abnormal grid-connected point;

[0181] In this embodiment, the control process in step S52 includes the following sub-steps:

[0182] Step S521, the rated reactive power of different energy storage converters is obtained, and the rated reactive power of different energy storage converters is added to obtain the total rated reactive power of the energy storage power station;

[0183] Step S522, the rated reactive power of different energy storage converters is divided by the total rated reactive power to obtain the proportion of the rated reactive power of different energy storage converters;

[0184] Step S523, the proportion of the rated reactive power is multiplied by the reactive power adjustment amount to obtain the individual reactive adjustment amount of different energy storage converters;

[0185] Step S524, the generated reactive power of the voltage abnormal grid-connected point is compared with the load reactive power;

[0186] If the generated reactive power of the voltage abnormal grid-connected point in the power grid is greater than the load reactive power, the energy storage converter is controlled to absorb the reactive power, and the absorption amount of different energy storage converters is the corresponding individual reactive adjustment amount;

[0187] If the active power of power generation of the frequency abnormal grid-connection point is less than the active power of load, the energy storage converter is controlled to send reactive power, and the sending amount of different energy storage converters is the corresponding individual reactive power adjustment amount;

[0188] In step S53, when the grid-connection point is a risk grid-connection point, the primary frequency modulation device continuously monitors the risk grid-connection point.

[0189] It should be explained that the active power of power generation of the frequency abnormal grid-connection point is not equal to the active power of load, and the reactive power of power generation of the voltage abnormal grid-connection point is not equal to the reactive power of load.

[0190] Embodiment two: please refer to Figure 3 As shown in the figure, based on another concept of the same invention, a self-adaptive model predictive control system for primary frequency modulation of energy storage power station is proposed, which includes a data acquisition module, a data calibration module, a data analysis module, a data calculation module, a power prediction module and an intelligent control module.

[0191] The data acquisition module is used to acquire electrical data of different grid-connection points in the power grid and send them to the data calibration module; the data calibration module is used to calibrate the measurement accuracy of the primary frequency modulation device; the data analysis module is used to construct the workflow of the self-adaptive model and analyze the state of the grid-connection points in the power grid, and obtain a normal state signal, a frequency abnormal grid-connection point or a voltage abnormal grid-connection point; if the normal state signal is generated, it is sent to the power prediction module; if the frequency abnormal grid-connection point or the voltage abnormal grid-connection point is obtained, it is sent to the data calculation module; the data calculation module is used to calculate the active power adjustment amount or the reactive power adjustment amount of the energy storage power station and send it to the intelligent control module; the power prediction module is used to predict the power of the grid-connection points in the power grid after receiving the normal state signal, generate a power abnormal signal and send it to the intelligent control module; the intelligent control module is used to control the energy storage converter in the energy storage power station.

[0192] The preferred embodiments of the application disclosed above are only used to help explain the application. The preferred embodiments do not describe all the details and do not limit the application to the specific embodiments. Obviously, according to the content of the specification, many modifications and changes can be made. The embodiments are selected and described in detail in order to better explain the principles and practical applications of the application, so that those skilled in the art can well understand and utilize the application. The application is limited by the claims and their entire scope and equivalents.

Claims

1. An adaptive model predictive control method for primary frequency regulation of an energy storage power station, characterized in that, The methods include: Step S1: Calibrate the measurement accuracy of the primary frequency modulation device; Step S2: Construct the workflow of the adaptive model and obtain the abnormal grid connection points in the power grid through the output of the adaptive model; Step S3: Calculate the active power adjustment or reactive power adjustment based on the output data of the adaptive model; Step S4: Predict the power balance status of different grid connection points in the power grid and obtain the risky grid connection points. Step S5: When there is an abnormal grid connection point or a risky grid connection point in the power grid, the abnormal grid connection point or the risky grid connection point shall be controlled accordingly. The control process in step S5 includes the following sub-steps: Step S51: When the grid connection point in the power grid is a frequency abnormality grid connection point, the primary frequency regulation device controls the frequency abnormality grid connection point. The control process is as follows: Step S511: Obtain the rated active power of different energy storage converters, and sum the rated active power of different energy storage converters to obtain the total rated active power of the energy storage power station. Step S512: Divide the rated active power of different energy storage converters by the total rated active power to obtain the ratio of rated active power of different energy storage converters. Step S513: Multiply the rated active power ratio by the active power adjustment amount to obtain the individual active power adjustment amount of different energy storage converters. Step S514: Compare the active power generated at the grid connection point with the active power of the load; If the active power of the generator at the grid connection point with abnormal frequency is greater than the active power of the load, then different energy storage converters will be charged, and the charging power will be the individual active power adjustment amount corresponding to different energy storage converters. If the active power of the generator at the grid connection point with abnormal frequency is less than the active power of the load, then different energy storage converters will be discharged, and the discharge power will be the individual active power adjustment amount corresponding to different energy storage converters. Step S52: When the grid connection point in the power grid is a voltage abnormality connection point, the primary frequency regulation device controls the voltage abnormality connection point. The control process is as follows: Step S521: Obtain the rated reactive power of different energy storage converters, and sum the rated reactive power of different energy storage converters to obtain the total rated reactive power of the energy storage power station. Step S522: Divide the rated reactive power of different energy storage converters by the total rated reactive power to obtain the ratio of rated reactive power of different energy storage converters. Step S523: Multiply the rated reactive power ratio by the reactive power adjustment amount to obtain the individual reactive power adjustment amount of different energy storage converters; Step S524: Compare the reactive power generated at the grid connection point with the reactive power of the load; If the reactive power of the generator at the grid connection point is greater than the reactive power of the load, the energy storage converter is controlled to absorb the reactive power. The absorption amount of different energy storage converters is the corresponding individual reactive power adjustment amount. If the active power generated at the grid connection point of the abnormal frequency in the power grid is less than the active power of the load, the reactive power output of the energy storage converter is controlled. The output of different energy storage converters is the corresponding individual reactive power adjustment amount. Step S53: When the grid connection point in the power grid is a risky grid connection point, the primary frequency regulation device continuously monitors the risky grid connection point.

2. The adaptive model predictive control method for primary frequency regulation of an energy storage power station according to claim 1, characterized in that, The calibration process in step S1 includes the following sub-steps: Step S11: Connect the primary frequency modulation device to the three-phase test circuit, input the initial current into the three-phase test circuit, and record the input initial current as the input current value of different phases. Step S12: Read the actual current values ​​of different phases displayed on the primary frequency modulation device, subtract the input current value from the actual current value, and divide by the input current value of the corresponding phase to obtain the current error rate of different phases in the primary frequency modulation device. Step S13: Compare the current error rate of different phases with the current error rate range; If the current error rate of all phases is within the current error rate range, then the input current value is increased stepwise and steps S12 and S13 are repeated until the input current value reaches the current measurement range of the primary frequency modulation device. If the current error rate of any phase is outside the current error rate range, the primary frequency modulation device is calibrated until the current error rate of the corresponding phase is within the current error rate range. Step S14: Similarly, input the initial voltage into the three-phase test circuit respectively, and repeat step S12 to calculate the voltage error rate of different phases in the primary frequency modulation device, and compare the voltage error rate of different phases with the voltage error rate range. If the voltage error rate of all phases is within the voltage error rate range, then the input voltage value is increased stepwise and steps S12 and S13 are repeated until the input voltage value reaches the voltage measurement range of the primary frequency modulation device. If the voltage error rate of any phase is outside the voltage error rate range, the primary frequency modulation device is calibrated until the voltage error rate of the corresponding phase falls within the voltage error rate range.

3. The adaptive model predictive control method for primary frequency regulation of an energy storage power station according to claim 2, characterized in that, The construction process in step S2 includes the following sub-steps: Step S21: First, collect the real-time frequency and real-time three-phase voltage of different grid connection points in the power grid at different time points, and use them as input values ​​for the adaptive model. Step S22: After the input value enters the adaptive model, the real-time frequency of different grid-connected points in the power grid at the current time node is compared with the standard frequency range, and the real-time three-phase voltage of different grid-connected points in the power grid at the current time node is compared with the standard voltage range. If, at the current time point, the real-time frequency of any grid connection point in the power grid is not within the standard frequency range, but the real-time three-phase voltage of all grid connection points is within the standard voltage range, then the corresponding grid connection point is recorded as a frequency abnormal grid connection point and proceeds to step S23. If the real-time frequency of all grid-connected points in the power grid at the current time node is within the standard frequency, but the real-time three-phase voltage of any grid-connected point is not within the standard voltage range, then the corresponding grid-connected point is recorded as a voltage abnormal grid-connected point and the process proceeds to step S23. If the real-time frequency of all grid-connected points in the power grid is not within the standard frequency range and the real-time three-phase voltage of all grid-connected points is not within the standard voltage range at the current time point, a maintenance warning will be issued immediately. If the real-time frequency of all grid-connected points in the power grid at the current time node is within the standard frequency range and the real-time three-phase voltage of all grid-connected points is within the standard voltage range, then proceed to step S4. Step S23: Record the frequency abnormal grid connection point and the voltage abnormal grid connection point as abnormal grid connection points in the power grid, and record the abnormal grid connection points as the output data of the adaptive model; Step S24: Steps S21-S23 are recorded as the workflow of the adaptive model.

4. The adaptive model predictive control method for primary frequency regulation of an energy storage power station according to claim 3, characterized in that, The calculation process in step S3 includes the following sub-steps: Step S31: Input the output data of the adaptive model into the primary frequency modulation device; Step S32: For grid connection points with abnormal frequencies, the primary frequency regulation device calculates the active power adjustment amount of the energy storage power station through the AGC unit. Step S33: For grid connection points with abnormal voltage, the primary frequency regulation device calculates the reactive power adjustment amount of the energy storage power station through the AVC unit.

5. The adaptive model predictive control method for primary frequency regulation of an energy storage power station according to claim 4, characterized in that, The calculation process in step S32 includes the following sub-steps: Step S321: Obtain the rated frequency, real-time frequency, rated active power of different energy storage converters, and maximum allowable frequency deviation of the grid connection point with frequency anomalies in the power grid. Step S322: Subtract the rated frequency from the real-time frequency to obtain the frequency difference value of the grid connection point with frequency anomaly in the power grid; Step S323: Divide the maximum frequency deviation by the rated active power of different energy storage power stations to obtain the droop coefficient of different energy storage converters, and sum the reciprocals of the droop coefficients of different energy storage converters to obtain the reciprocal of the total droop coefficient of the energy storage power station. Step S324: Calculate the active power adjustment amount of the energy storage power station.

6. The adaptive model predictive control method for primary frequency regulation of an energy storage power station according to claim 5, characterized in that, The calculation process in step S33 includes the following sub-steps: Step S331: Obtain the rated voltage, real-time voltage, rated reactive power of different energy storage converters, and maximum allowable voltage deviation of the grid connection point with voltage anomalies in the power grid. Step S332: Subtract the rated voltage from the real-time voltage to obtain the voltage difference at the grid connection point where the voltage is abnormal. Step S333: Divide the maximum voltage deviation by the rated reactive power of different energy storage power stations to obtain the droop coefficient of different energy storage converters, and sum the reciprocals of the droop coefficients of different energy storage converters to obtain the reciprocal of the total droop coefficient of the energy storage power station. Step S334: Calculate the reactive power adjustment amount of the energy storage power station.

7. The adaptive model predictive control method for primary frequency regulation of an energy storage power station according to claim 6, characterized in that, The prediction process in step S4 includes the following sub-steps: Step S41: Collect the load three-phase voltage, load three-phase current and real-time phase difference at different load terminals of the power grid at different time points, and record the load three-phase voltage, load three-phase current and real-time phase difference as load electrical data; Step S42: Calculate the load line voltage at the load end of the grid connection point in the power grid, and record the three-phase load current as the load line current at the load end of the grid connection point in the power grid. Step S43: Calculate the active power of the load at the grid connection point in the power grid at different time nodes; Similarly, repeat steps S41-S42 to collect the load electrical data at the load end of the grid connection point where the voltage is abnormal, and calculate the reactive power of the load at the load end of the grid connection point at different time nodes. Step S44: Repeat steps S41-S43 to calculate the active power and reactive power of the generator at the grid connection point in the power grid at different time nodes. Step S45: Subtract the load active power from the generator active power at the grid connection point in the current time node and take the absolute value to obtain the active power difference value at the grid connection point in the current time node. Similarly, the difference in reactive power between grid-connected points at the current time node is obtained by subtracting the reactive power of the load from the reactive power of the generator at the current time node and taking the absolute value. Similarly, the differences in active power and reactive power at grid connection points in the power grid at different time points are calculated. Step S46: Analyze the differences in active power and reactive power at grid connection points in the power grid at different time points; Step S47: Record the frequency risk grid connection point and the voltage risk grid connection point as risk grid connection points.

8. The adaptive model predictive control method for primary frequency regulation of an energy storage power station according to claim 7, characterized in that, The analysis process in step S46 includes the following sub-steps: Step S461: Obtain the maximum allowable active power difference and the maximum reactive power difference at the grid connection point in the power grid. Step S462: Use half of the maximum active power difference value as the active power difference warning value, and use half of the maximum reactive power difference value as the reactive power difference warning value. Step S463: The time node corresponding to the active power difference value being greater than or equal to the active power difference warning value is recorded as the first time node, and the time node corresponding to the active power difference value being less than the active power difference warning value is recorded as the second time node. Similarly, the time node corresponding to the reactive power difference value being greater than or equal to the reactive power difference warning value is recorded as the third time node, and the time node corresponding to the reactive power difference value being less than the reactive power difference warning value is recorded as the fourth time node. Step S464: Count the number of first time nodes and the number of second time nodes within a fixed time period, and compare the number of first time nodes and the number of second time nodes within a fixed time period. If the number of first time nodes within a fixed time period is greater than or equal to the number of second time nodes, then the corresponding grid connection point will be recorded as a frequency risk grid connection point. If the number of first time nodes within a fixed time period is less than the number of second time nodes, no operation will be performed. Similarly, count the number of third and fourth time nodes within a fixed duration, and compare the number of third and fourth time nodes within the fixed duration. If the number of third time nodes within a fixed time period is greater than or equal to the number of fourth time nodes, then the corresponding grid connection point will be recorded as a voltage risk grid connection point. If the number of third time nodes within a fixed time period is less than the number of fourth time nodes, no operation will be performed.

9. An adaptive model predictive control system for primary frequency regulation of an energy storage power station, characterized in that, The adaptive model predictive control method for primary frequency regulation of an energy storage power station according to any one of claims 1-8 includes: The data acquisition module is used to collect electrical data at different grid connection points in the power grid and send it to the data calibration module; The data calibration module is used to calibrate the measurement accuracy of the primary frequency modulation device; The data analysis module is used to build the workflow of the adaptive model and analyze the status of grid connection points in the power grid. The analysis results in a normal status signal, a grid connection point with abnormal frequency, or a grid connection point with abnormal voltage. If a normal status signal is generated, it is sent to the power prediction module; if a grid connection point with abnormal frequency or abnormal voltage is obtained, it is sent to the data calculation module. The data calculation module is used to calculate the active power adjustment or reactive power adjustment of the energy storage power station and send it to the intelligent control module. The power prediction module is used to predict the power of the grid connection point after receiving the normal status signal, generate the power anomaly signal and send it to the intelligent control module. The intelligent control module is used to control the energy storage converter in the energy storage power station.

Images