CN108667037B - STATCOM/BESS microgrid cooperative control method and system based on P-DPC - Google Patents
STATCOM/BESS microgrid cooperative control method and system based on P-DPC Download PDFInfo
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Abstract
本发明公开了一种对微电网中的STATCOM/BESS装置改进的控制方法及其系统，属于电能质量优化领域，电网的电源输出端和负载之间连接有STATCOM，STATCOM中的电压逆变器的两端并联有蓄电池组组成STATCOM/BESS，电源输出端依次连接有瞬时功率计算模块、功率预测模块和SVPWM调制模块，SVPWM调制模块的输出端输出目标矢量信号驱动STATCOM中的三相桥臂。本发明通过对微电网中的STATCOM/BESS装置进行改机，使得STATCOM/BESS系统输出功率波动小、直流侧电压稳定且具有很好的功率跟踪控制和快速调节功率能力。
The invention discloses an improved control method and system for a STATCOM/BESS device in a microgrid, belonging to the field of power quality optimization. Both ends are connected in parallel with battery packs to form STATCOM/BESS. The output end of the power supply is sequentially connected with an instantaneous power calculation module, a power prediction module and an SVPWM modulation module. The output end of the SVPWM modulation module outputs a target vector signal to drive the three-phase bridge arm in the STATCOM. By modifying the STATCOM/BESS device in the microgrid, the invention makes the output power fluctuation of the STATCOM/BESS system small, the DC side voltage is stable, and has good power tracking control and fast power adjustment capability.
Description
Technical Field
The invention belongs to the field of power quality optimization, relates to a method for optimizing and controlling the power quality of a micro-grid, and particularly relates to an improved control method and an improved control system for a STATCOM/BESS device in the micro-grid.
Background
The distributed micro-grid technology has attracted great attention of researchers in various countries as one of the key technologies of modern power systems, and becomes an important surface in the research of the power industry in recent years. The role of static synchronous compensators (STATCOM) in reactive compensation capability and voltage stabilization in the grid makes them widely used in micro-grids. However, the voltage-type inverter in the STATCOM mainly performs reactive power exchange with the microgrid system in the working process, and the effect of the STATCOM is deficient when active loss exists in the system. If a storage battery system (BESS) is added into the STATCOM system, a novel device which can perform reactive power compensation on the system and adjust active power is combined, namely the STATCOM/BESS with the storage battery energy storage system. The reasonable control of the device can effectively realize the optimization of the quality of the electric energy.
In the traditional Direct Power Control (DPC), a switch state is selected by a voltage vector prestored in a switch table, and a pulse generation module is used for controlling the on-off of a switch tube on a three-phase bridge arm so as to regulate power. Therefore, the core of direct power control is a switch table module, and the accuracy of the corresponding relation between the voltage vector of the switch table and the switch state directly influences the control effect. The direct power control (P-DPC) under the traditional prediction power can realize the flexible change of the switching frequency without the fixed corresponding relation of the voltage vector and the switching state on the switch table, thereby controlling the STATCOM/BESS system. However, in order to simplify the algorithm, the control method applied to the PWM rectifier usually sets the reactive power to zero and then performs control, and the control effect on the active power and the reactive power needs to be comprehensively considered in the microgrid system having the STATCOM/BESS device, so that the control method may cause insufficient reactive power control, and the error of the linear interpolation prediction reference power adopted by the control method is large.
Disclosure of Invention
According to the defects of the prior art, the technical problem to be solved by the invention is to provide an improved control method and system for the STATCOM/BESS device in the micro-grid, so that the output power fluctuation of the STATCOM/BESS system is small, the voltage on the direct current side is stable, and the STATCOM/BESS system has good power tracking control and rapid power regulation capability.
In order to solve the technical problems, the invention adopts the technical scheme that: a STATCOM/BESS micro-grid cooperative control system based on a P-DPC is characterized in that a STATCOM is connected between a power output end of a power grid and a load, storage battery packs are connected in parallel to two ends of a voltage inverter in the STATCOM to form the STATCOM/BESS, an instantaneous power calculation module, a power prediction module and an SVPWM modulation module are sequentially connected to the power output end, and a target vector signal is output by the output end of the SVPWM modulation module to drive a three-phase bridge arm in the STATCOM.
In the system, the STATCOM/BESS outputs active power and reactive power data to the instantaneous power calculation module for calculation, load active power and reactive power data are calculated, and STATCOM/BESS reference active power and reactive power data are generated according to the load power, so that the STATCOM/BESS can restrain the impact of load power fluctuation on a power grid. And the input quantity of the power prediction module is the current power grid voltage, the reference power of the STATCOM/BESS and the actual power data, and a target voltage vector is obtained after calculation.
A STATCOM/BESS microgrid cooperative control method based on P-DPC comprises the following steps:
the method comprises the following steps: establishing a mathematical model of STATCOM/BESS; and the mathematical model of the BESS in the first step adopts a linear circuit model.
Step two: detecting the current time power grid voltage, the STATCOM/BESS compensation current and the load current value, and calculating the current time STATCOM/BESS output power and the current time load power; in the second step: and calculating a new expression of the STATCOM alternating current output voltage by using the derived P-DPC control algorithm according to the output power and the load power.
Step three: recording reference power values at k-2, k-1 and k moments, and calculating reference power at k +1 moment; in the third step, the prediction reference power is calculated by using a second-order Lagrange interpolation method, and the process is as follows: with three known points having respective coordinates of (x)0,y0)、(x1,y1)、(x2,y2) Then the coordinates of the predicted point y are:
the reference power at time (k +1) is
In the formula, Pref(k-2)、Pref(k-1)、Pref(k) And Qref(k-2)、Qref(k-1)、Qref(k) Respectively the active and reactive reference powers at the moments k-2, k-1, k, the active and reactive reference powers at the moments k-2, k-1, k can be obtained by tracking the instantaneous power of the load, Pref(k +1) and QrefAnd (k +1) is the active and reactive reference power at the moment k + 1.
Step four: and (5) performing derivation calculation on the three steps to obtain a STATCOM alternating current side voltage vector expression.
Step five: and sending the obtained reference power value and the power grid voltage value at the current moment detected by the reference power at the moments of k-2, k-1 and k to an SVPWM (space vector pulse width modulation) module to complete fixed-frequency control of the converter.
The control method has the beneficial effects that the STATCOM/BESS device has good power tracking control and rapid power regulation effects in the micro-grid through the control method. In order to overcome the defect that the reactive power is generally set to zero so as to simplify the defect that a control algorithm has large influence on the reactive power output of the STATCOM/BESS device in a control strategy of combining power prediction and direct power control (P-DPC for short) adopted in the prior art, the P-DPC control algorithm is deduced again on the basis of considering the variable of the reactive power, and the second-order Lagrange interpolation algorithm is adopted to replace the traditional linear interpolation algorithm to improve the reference power prediction precision. The method provided by the invention can ensure that the output power fluctuation of the STATCOM/BESS system is small, the voltage of the direct current side is stable, and the STATCOM/BESS system has good power tracking control and rapid power regulation capability.
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The contents of the drawings and the reference numerals in the drawings are briefly described as follows:
FIG. 1 is an application control block diagram of an embodiment of the present invention.
FIG. 2 is a graph of simulation results of phase A voltage and phase current for a system before improvement in a microgrid system according to an embodiment of the present invention;
FIG. 3 is a graph of simulation results of phase A voltage and phase current of the improved system in the microgrid system according to an embodiment of the present invention;
FIG. 4 is a graph of reactive power simulation results for the output of a pre-retrofit STATCOM/BESS device in a microgrid system in accordance with an embodiment of the present invention;
FIG. 5 is a diagram of the reactive power simulation results of the improved STATCOM/BESS device output in the microgrid system according to an embodiment of the present invention.
Detailed Description
The following description of the embodiments with reference to the drawings is provided to describe the embodiments of the present invention, and the embodiments of the present invention, such as the shapes and configurations of the components, the mutual positions and connection relationships of the components, the functions and working principles of the components, the manufacturing processes and the operation and use methods, etc., will be further described in detail to help those skilled in the art to more completely, accurately and deeply understand the inventive concept and technical solutions of the present invention.
A STATCOM/BESS microgrid cooperative control method based on P-DPC comprises the following steps:
the method comprises the following steps: and establishing a mathematical model of STATCOM/BESS. The accuracy of the STATCOM/BESS mathematical model building is the basis of researching the STATCOM/BESS operation characteristics and controller design, the accurate mathematical model building of the STATCOM/BESS overall device is the necessary condition of the STATCOM/BESS device performance characteristic analysis and the application of the correct control method, and therefore the accuracy of the built mathematical model directly influences the design and system simulation of the controller. In the mathematical model established in the invention, the mathematical model of the storage Battery (BESS) adopts a linear circuit model, the mathematical model of the STATCOM adopts a three-phase inversion two-level bridge circuit model, and the STATCOM/BESS device can emit or absorb active and reactive currents meeting the requirements by changing the amplitude and the phase of the alternating current output voltage, so that the reactive power and the active power required by a dynamic compensation system are realized.
And step two, after the model is successfully established, detecting the current time of the power grid voltage, the STATCOM/BESS compensation current and the load current value, and calculating the current time of the STATCOM/BESS output power and the load power, namely calculating the load active power and reactive power values. The detection of the power grid voltage at the present moment adopts an alternating voltage sampling circuit, and the voltage is reduced through an isolation step-down transformer, and then the low-voltage alternating voltage is changed into a low-voltage alternating current signal to be subjected to subsequent filtering and amplification processing. After the voltage transformation of the transformer, direct current bias needs to be added to the alternating current signal, so that the signal potential is integrally improved. The sampling mode is convenient, simple in structure and easy to realize, and an isolation step-down transformer is added between the control part and the output. The detection of load current value and STATCOM/BESS compensation current adopts a Hall sensor circuit, a current signal is changed into a voltage signal through a sensor, and compared with alternating current voltage detection, the alternating current detection only replaces a transformer with the sensor, and a back end circuit is consistent with an alternating current voltage detection circuit.
Reactive power of the STATCOM/BESS system is present and not negligible, and conventional P-DPC control cannot regulate reactive power. In order to strengthen the control of the reactive power and solve the problems of insufficient control of the reactive power, insufficient power tracking caused by low control response speed and the like, the derivation of the P-DPC algorithm is carried out again so as to obtain a new expression of the STATCOM alternating current output voltage, the problem that the traditional P-DPC control algorithm generates large reactive power fluctuation when being applied to the STATCOM/BESS is solved, and the fixed-frequency control of SVPWM on the device is favorably realized.
In order to improve the reactive power output of the STATCOM/BESS device, the P-DPC control algorithm is re-derived on the basis of considering the variable of the reactive power. Will micro-grid voltage ua、ub、ucAC side voltage e of AC converterabcCurrent iabcPerforming a clark transformation (the clark transformation is a common data transformation method in the art and is not described herein again), so that usα、usβThe voltages e of the transformed microgrid on the alpha and beta axes respectivelysα、esβThe voltages i on the AC side of the AC converter corresponding to the alpha and beta axes after clark conversionα、iβThe output currents of the ac converters corresponding to the α and β axes after clark conversion are respectively. Then, the instantaneous power theory shows that the output active power P and the reactive power Q of the STATCOM/BESS device are respectively:
P＝usαiα+usβiβ，Q＝-usαiβ+usβiα (1)
discretizing the variable in formula (1) results in: the instantaneous power at time k is:
P(k)＝usα(k)iα(k)+usβ(k)iβ(k)，Q(k)＝-usα(k)iβ(k)+usβ(k)iα(k) (2)
in the formula (2), usα(k)、usβ(k) Respectively, the microgrid voltage u at the moment ka(k)、ub(k)、uc(k) Corresponding microgrid voltages i on the alpha and beta axes after clark transformationα(k)、iβ(k) Output current i of AC converter at time ka(k)、ib(k)、ic(k) And (3) outputting current of the corresponding alternating current converters on the alpha axis and the beta axis after clark conversion, wherein P (k), Q (k) are instantaneous active power and reactive power of the output of the STATCOM/BESS device at the k moment.
According to the sampling theory, the following steps are known: when the sampling frequency is much higher than the grid voltage frequency, the grid voltage can be considered as invariant, i.e.
usα(k+1)＝usα(k),usβ(k+1)＝usβ(k) (3)
In the formula (3), usα(k+1)、usβ(k +1) is the microgrid voltage u at the moment k +1a(k+1)、ub(k+1)、uc(k +1) the microgrid voltages corresponding to the alpha and beta axes after clark transformation.
By combining the equations (2) and (3), the change of the output power of the STATCOM/BESS device from the time k to the time k +1 can be obtained as follows:
in the formula (4), P (k +1) and Q (k +1) are instantaneous active power and reactive power output by the STATCOM/BESS device at the moment of k +1 respectively, iα(k+1)、iβ(k +1) is the output current i of the AC converter at the moment of k +1 respectivelya(k+1)、ib(k+1)、ic(k +1) the output currents of the corresponding alternating current converters on the alpha and beta axes after clark conversion.
Let the sampling period be TsThen, the predicted current at time k +1 is:
in the formula (5), R and L are eachResistors and inductors, e, other than STATCOM/BESS connections to the microgrid systemsα(k)、esβ(k) Voltage e at AC side of AC converter at time ka(k)、eb(k)、ec(k) And the voltages at the alternating current sides of the alternating current converters corresponding to the alpha and beta axes after clark conversion.
Substituting (5) into (4) to obtain:
the vector e of the voltage on the AC side of the STATCOM is obtained from the above equationsα(k)、esβ(k)：
And the purpose of the step two is to calculate the load active power and reactive power values by obtaining the vector expression of the STATCOM AC side voltage containing P (k + 1).
Step three: the reference power values at time k-2, k-1 and k are recorded. Specifically, reference active power and reactive power values of the STATCOM/BESS are generated according to the load power, so that the STATCOM/BESS can restrain the impact of load power fluctuation on a power grid and keep the output power of the power grid basically stable. The reference power is predicted by linear interpolation in the calculation process, in order to avoid larger error caused by the reference power algorithm of linear interpolation prediction, the reference power is predicted by replacing the linear interpolation by a second-order Lagrange interpolation method, the algorithm is simple, the calculated amount is small, and the dynamic response speed of the system can be improved.
Second order lagrange interpolation: with three known points having respective coordinates of (x)0,y0)、(x1,y1)、(x2,y2) Then the predicted point coordinates are:
the reference power at time (k +1) is:
in the formula, Pref(k-2)、Pref(k-1)、Pref(k) And Qref(k-2)、Qref(k-1)、Qref(k) Respectively the active and reactive reference powers at the moments k-2, k-1, k, the active and reactive reference powers at the moments k-2, k-1, k can be obtained by tracking the instantaneous power of the load, Pref(k +1) and QrefAnd (k +1) is the active and reactive reference power at the moment k + 1.
Step four: in order to enhance the control effect on the reactive power, on the basis of the step re-derivation of the P-DPC algorithm, the reference power value obtained in the step three and the reference power at the time of k-2, k-1 and k are substituted by derivation calculation, and in order to ensure the accuracy of the control, the reference power value is obtained
Then, the vector expression of the voltage at the ac side of the STATCOM can be obtained:
step five: calculating the voltage vector e according to the formulasα(k)、esβ(k) And the SVPWM modulation module is used for realizing the on-off of a three-phase bridge arm, fixing the switching frequency of the converter, and stating the fixed-frequency control process by combining the alternating-current side voltage value calculated in the step four to realize the fixed-frequency control of the converter. By the control method, the STATCOM/BESS device has good power tracking control and rapid power regulation effects in the microgrid.
A P-DPC-based STATCOM/BESS microgrid cooperative control system is applied to a STATCOM/BESS device system, a STATCOM is connected between a power output end of a microgrid and a load, storage battery packs are connected in parallel at two ends of a voltage inverter in the STATCOM to form the STATCOM/BESS, the power output end is sequentially connected with an instantaneous power calculation module, a power prediction module and an SVPWM modulation module, and an output end of the SVPWM modulation module outputs a target vector signal to drive a three-phase bridge arm in the STATCOM. Compared with the traditional direct power control system, the P-DPC-based STATCOM/BESS micro-grid cooperative control system omits a hysteresis comparator and a switch table module, and adds a power prediction module and an SVPWM (space vector pulse width modulation) module.
And the instantaneous power calculation module is mainly used for finishing the calculation of the active power and the reactive power output by the STATCOM/BESS and the calculation of the active power and the reactive power of the load, and generating the reference active power and the reference reactive power of the STATCOM/BESS according to the load power, so that the STATCOM/BESS can inhibit the impact of the load power fluctuation on the power grid and keep the output power of the power grid basically stable. The instantaneous power calculation module calculates the reactive power value by using the P-DPC control algorithm after re-derivation, and solves the problem that the reactive power fluctuates greatly when the traditional P-DPC is directly applied to the STATCOM/BESS.
And the power prediction module is mainly used for calculating the voltage of the alternating current side of the STATCOM, the input quantity is the current power grid voltage, the reference power and the actual power of the STATCOM/BESS, and a target voltage vector is obtained after calculation. The power prediction module predicts the reference power by using a second-order Lagrange interpolation method, and the algorithm is simple and has small calculation amount.
And the SVPWM modulation module drives the three-phase bridge arm switch to be switched on and off according to the target voltage vector to complete fixed frequency control on the frequency converter so as to synthesize the target voltage vector.
The P-DPC-based STATCOM/BESS microgrid cooperative control method is applied to a STATCOM/BESS device system, and has the advantages of high dynamic response speed and good power tracking accuracy. As shown in fig. 2 to 5, the simulation result diagram is obtained by applying the cooperative control method of the STATCOM/BESS microgrid based on the P-DPC to the microgrid system with nonlinear loads, wherein the inductive loads are suddenly changed into the capacitive loads.
The load type in the microgrid system abruptly changes at 0.1s, but the system current remains substantially unchanged, as shown in fig. 2, due to reactive power regulation of the STATCOM/BESS installation.
In fig. 2, the current waveform lags the voltage waveform a little before 0.1s and the current waveform leads the voltage waveform a little after 0.1s because the load type in the microgrid system abruptly changes from an inductive load to a capacitive load at 0.1 s.
In fig. 3, the improved control strategy enables the voltage waveform and the current waveform of the system to be basically consistent in phase, and has better power regulation capability than before the improvement.
From fig. 4 and 5, it can be seen that the STATCOM/BESS device performs reactive power compensation or absorption when the load type in the system changes suddenly, and the improved regulation time is shorter, which shows that the improved device has the function of rapid power regulation.
The invention has been described above with reference to the accompanying drawings, it is obvious that the invention is not limited to the specific implementation in the above-described manner, and it is within the scope of the invention to apply the inventive concept and solution to other applications without substantial modification. The protection scope of the present invention shall be subject to the protection scope defined by the claims.
Claims (2)
1. A STATCOM/BESS microgrid cooperative control method based on P-DPC is characterized by comprising the following steps:
the method comprises the following steps: establishing a mathematical model of the STATCOM/BESS, wherein the mathematical model of the BESS adopts a linear circuit model, the mathematical model of the STATCOM adopts a three-phase inversion two-level bridge circuit model, and the STATCOM/BESS device sends out or absorbs active and reactive currents meeting the requirements by changing the amplitude and the phase of alternating current output voltage so as to realize reactive power and active power required by a dynamic compensation system;
step two: detecting the current time power grid voltage, the STATCOM/BESS compensating current and the load current value, calculating the STATCOM/BESS output power and the load power of the current time, adopting an alternating voltage sampling circuit for detecting the current time power grid voltage, carrying out voltage reduction treatment through an isolation step-down transformer, changing the voltage reduction treatment into a low-voltage alternating current signal, then carrying out subsequent filtering and amplification treatment, adding direct current bias to the alternating current signal after transformer transformation, integrally improving the signal potential, detecting the load current value and the STATCOM/BESS compensating current, adopting a Hall sensor circuit, and changing the current signal into a voltage signal through a sensor;
step three: recording reference power values at k-2, k-1 and k time, and calculating the reference power at k +1 time as
In the formula, Pref(k-2)、Pref(k-1)、Pref(k) And Qref(k-2)、Qref(k-1)、Qref(k) Respectively the active and reactive reference powers at the moments k-2, k-1 and k, the active and reactive reference powers at the moments k-2, k-1 and k are obtained by tracking the instantaneous power of the load, Pref(k +1) and Qref(k +1) is the active and reactive reference power at the moment k + 1;
step four: the third step is subjected to derivation calculation, and the reference power value obtained in the third step and the reference power at the k-2, k-1 and k moments are substituted in through derivation calculation, so that
Obtaining an expression of a STATCOM alternating-current side voltage vector:
step five: sending the obtained reference power value, the reference power at the moments k-2, k-1 and k and the detected grid voltage value at the current moment to an SVPWM (space vector pulse width modulation) module to complete fixed-frequency control of the converter;
in the second step: calculating a new expression of the STATCOM alternating current output voltage by utilizing a derived P-DPC control algorithm according to the output power and the load power;
the method comprises the following steps of performing click conversion on microgrid voltages ua, ub and uc, alternating current converter alternating current side voltage eabc and current iabc to obtain us alpha and us beta which are respectively converted microgrid voltages corresponding to an alpha axis and a beta axis, es alpha and es beta which are respectively converted alternating current converter alternating current side voltages corresponding to the alpha axis and the beta axis, and i alpha and i beta which are respectively converted alternating current converter output currents corresponding to the alpha axis and the beta axis, wherein the output active power P and the reactive power Q of the STATCOM/BESS device are respectively known by an instantaneous power theory as follows:
P＝usαiα+usβiβ，Q＝-usαiβ+usβiα； (1)
discretizing the variable in formula (1) results in: the instantaneous power at time k is:
P(k)＝usα(k)iα(k)+usβ(k)iβ(k)，Q(k)＝-usα(k)iβ(k)+usβ(k)iα(k) (2)
in the formula (2), us α (k) and us β (k) are microgrid voltages ua (k), ub (k) and uc (k) corresponding to the microgrid voltages on the α and β axes after clark conversion at the time k, i α (k) and i β (k) are output currents ia (k), ib (k) and ic (k) corresponding to the ac converter output currents on the α and β axes after clark conversion at the time k, respectively, and p (k) and q (k) are instantaneous active power and reactive power output by the STATCOM/BESS device at the time k;
according to the sampling theory, the following steps are known: when the sampling frequency is much higher than the grid voltage frequency, the grid voltage is considered as being constant, i.e. it is
usα(k+1)＝usα(k),usβ(k+1)＝usβ(k)； (3)
In the formula (3), us α (k +1) and us β (k +1) are the microgrid voltages corresponding to the α and β axes after the microgrid voltages ua (k +1), ub (k +1) and uc (k +1) are subjected to clark conversion at the moment of k +1 respectively;
by combining the equations (2) and (3), the change of the output power of the STATCOM/BESS device from the time k to the time k +1 can be obtained as follows:
in the formula (4), P (k +1) and Q (k +1) are respectively instantaneous active power and reactive power output by the STATCOM/BESS device at the moment k +1, and i α (k +1) and i β (k +1) are respectively corresponding alternating current converter output currents on α and β axes after clark transformation of alternating current converter output currents ia (k +1), ib (k +1) and ic (k +1) at the moment k + 1;
let the sampling period be Ts, the predicted current at time k +1 is:
in the formula (5), R and L are respectively a resistor and an inductor connected with the STATCOM/BESS and the microgrid system, and es alpha (k) and es beta (k) are respectively alternating current side voltages ea (k), eb (k) and ec (k) of the alternating current converter at the time k, which are converted by clark, on the alpha axis and the beta axis;
substituting (5) into (4) to obtain:
then the vectors es alpha (k), es beta (k) of the STATCOM AC side voltage are obtained by the following formula:
in the third step, the prediction reference power is calculated by using a second-order Lagrange interpolation method, and the process is as follows: if there are three known points with coordinates (x0, y0), (x1, y1), (x2, y2), the coordinate of the predicted point y is:
the reference power at time (k +1) is
In the formula, Pref (k-2), Pref (k-1), Pref (k) and Qref (k-2), Qref (k-1) and Qref (k) are respectively the active and reactive reference power at the time k-2, k-1 and k, the active and reactive reference power at the time k-2, k-1 and k are obtained by tracking the instantaneous power of the load, and Pref (k +1) and Qref (k +1) are the active and reactive reference power at the time k + 1.
2. A STATCOM/BESS microgrid cooperative control system based on P-DPC is used for executing the method of claim 1, a STATCOM is connected between a power output end of a power grid and a load, storage battery packs are connected in parallel at two ends of a voltage inverter in the STATCOM to form the STATCOM/BESS, the STATCOM/BESS is characterized in that the power output end is sequentially connected with an instantaneous power calculation module, a power prediction module and an SVPWM modulation module, and a target vector signal is output by the output end of the SVPWM modulation module to drive a three-phase bridge arm in the STATCOM;
the STATCOM/BESS outputs active power and reactive power data to an instantaneous power calculation module for calculation, load active power and reactive power data are calculated, and STATCOM/BESS reference active power and reactive power data are generated according to the load power, so that the STATCOM/BESS can suppress the impact of load power fluctuation on a power grid;
and the input quantity of the power prediction module is the current power grid voltage, the reference power of the STATCOM/BESS and the actual power data, and a target voltage vector is obtained after calculation.
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