40 results about "Inner current loop" patented technology

The invention discloses a high-voltage direct-current cable state online monitoring method and system based on MMC low-frequency injection. The method comprises the steps that an MMC controller injects a low-frequency three-phase alternating-current signal into a direct-current cable based on an MMC low-frequency injection control strategy; the MMC low-frequency injection control strategy comprises the steps that an MMC controller adopts a double-closed-loop control mode composed of an outer voltage loop and an inner current loop; a voltage error is calculated through an outer voltage loop, and a differential-mode voltage Udiffdq * and a common-mode voltage Ucomdq * are calculated through an inner current loop, so that the MMC outputs a target voltage Ugoal signal to a direct-current cable; according to the method, active injection of the low-frequency alternating-current signal with the specific frequency and amplitude is achieved by setting the specific MMC control strategy, a hardware structure of a main loop of an MMC system does not need to be modified, and implementation is safe, easy, convenient and flexible; and meanwhile, online quantitative evaluation of the insulation state of the direct-current cable is realized, and the monitoring process is high in precision, simple, convenient and efficient.

Disclosed in the present invention is a variable coefficient equivalent SISO model based stability analysis method for a grid-connected converter system, comprising the following steps: constructing a variable coefficient equivalent SISO model; obtaining a complex space vector open-loop transfer function on the basis of the variable coefficient equivalent SISO model; and obtaining Nyquist curves under different current loop parameters or phase-locked loop parameters on the basis of the complex space vector open-loop transfer function. If the Nyquist curves surround point (-1,0), the grid-connected converter system is stable; and if the Nyquist curves do not surround point (-1,0), the grid-connected converter system is unstable. The present invention performs small disturbance modeling on the grid-connected converter system, considers the influence of mutual coupling between the phase-locked loop and the inner current loop, and derives a variable coefficient SISO open-loop transfer function capable of characterizing an MIMO system. Compared with the technical solution in the prior art that actual working conditions are not considered, the method disclosed in the present invention can more accurately analyze the system stability of the system under variable working conditions and variable parameters.

The invention discloses a sliding mode control and disturbance observer collaborative STATCOM construction method for suppressing LCC-HVDC commutation failure. The sliding mode control and disturbance observer collaborative STATCOM construction method comprises the steps that sliding mode control is adopted for current inner loop control of an STATCOM control circuit; the sliding mode control comprises a sliding mode surface, an index reaching law and a sliding mode control law; a sliding mode disturbance observer is introduced to estimate actual disturbance; actual disturbance estimated by the sliding mode disturbance observer is added to the sliding mode control law, and a corrected sliding mode control law is constructed. According to the novel STATCOM based on SMC-SMDO cooperative control, a multi-target sliding mode surface is designed, comprehensive optimization is realized in combination with an exponential reaching law, a sliding mode disturbance observer is introduced to weaken the influence of disturbance, and reactive power can be quickly injected to improve the commutation failure defense capability. Meanwhile, due to the introduction of the sliding mode disturbance observer, the disturbance of the system is estimated, the disturbance is accurately compensated, the precision of the STATCOM is greatly improved, the fault recovery time is effectively shortened, and the anti-interference performance is remarkably enhanced.

The invention discloses a speed loop two-degree-of-freedom PI control method and device based on feedforward and a medium, and relates to the technical field of speed loop control methods.According to the method, on the premise that the bandwidth of an inner current loop is higher than that of a speed loop, a PI feedback steady state is adopted, and a disturbance observer is used for load disturbance estimation and compensation; feedforward forming is introduced to a given side, a'given-output 'closed loop is shaped into a first-order or critical damping second-order target model, and a disturbance observer time constant, a target bandwidth and a sampling period are systematically set. The device is composed of an error acquisition module, a PI feedback module, a disturbance observation module, a feed-forward forming module and an execution interface module. According to the scheme, under the condition that hardware is not changed, rapid low-overshoot tracking is achieved, the anti-interference performance is not weakened, parameters can be reused, and the method is suitable for servo scenes such as numerical control, robots and stabilized platforms.

A series-resonant dual-active-bridge (SR-DAB) converter with an interleaved integrated-bidirectional-converter (IBC) and its associated control strategy is configured to improve transient response and stabilize a converter system in the presence of an input filter and cabling. The associated control strategy incorporates three parts. A main feedback control loop regulates the output voltage based on a reference signal by adjusting the frequency and phase shift of the SR-DAB converter. Virtual impedance control and active damping is provided by a feedforward controller configured to modify the reference signal. An IBC controller includes two loops, a slower outer voltage loop and a faster inner current loop, and is configured to improve transient response. In buck mode the IBC controller stores energy on an auxiliary capacitor when the output voltage is rising and in boost mode the stored energy is returned to the load when the output voltage is falling.

This invention belongs to the field of high-voltage direct current (HVDC) transmission in power systems, specifically relating to a method, equipment, and medium for AC fault ride-through control at the sending end of a new energy source transmission system via a DRU-HVDC. When an AC fault occurs at the sending end, the grid-side converter of the new energy power station exits the active, reactive, and voltage loops, retains the inner current loop, and switches to maximum current output mode, locking the frequency to the rated value. Simultaneously, the receiving-end converter station exits the DC voltage outer loop, retains the inner current loop, and controls the DC current according to preset commands. During the fault duration, the diode rectifier station remains on and transmits maximum active power. After the fault is cleared, the output current of the new energy power station is reduced to the rated value, and then the power and voltage control loops are restored; the receiving-end converter station resumes constant DC voltage operation. This invention achieves maximum power control through preset commands. By controlling and switching between the new energy power station and the receiving-end converter station, the DRU is effectively maintained on, improving the active power transmission capacity and system recovery speed during faults.

The invention discloses an active lag power factor correction system, which belongs to the technical field of power factor correction control, and comprises a double-closed-loop control circuit consisting of a low-speed outer voltage loop circuit and a high-speed inner current loop circuit, on one hand, the low-speed outer voltage loop circuit is used for stabilizing input voltage, and on the other hand, the high-speed inner current loop circuit is used for stabilizing output voltage; on the other hand, the low-speed outer voltage loop circuit is used for providing a reference signal for the high-speed inner current loop circuit; the fast inner current loop circuit controls the input current to follow the input voltage based on the reference signal. Compared with the prior art, the system solves the technical problem that traditional PFC control is sensitive to an EMI filter through an innovative control strategy of injecting an input voltage orthogonal component, achieves the technical effects of high PF, low THDI, high adaptability and high reliability, improves the system efficiency, reduces the application cost, and has remarkable engineering value.

This application discloses a grid-connected inverter control method based on a notch filter phase-locked loop (PLL) for weak grid conditions. The method first designs a notch filter with adjustable notch depth and bandwidth, setting its notch frequency to the grid power frequency. It then acquires the three-phase voltage at the grid connection point, subtracts the voltage after notching, and extracts the power frequency component of the three-phase voltage. The power frequency component is phase-locked in a synchronous reference frame to obtain the modulation wave phase signal. The inverter output voltage and current are acquired, and active and reactive power are calculated. A dual closed-loop control circuit with an outer power loop and an inner current loop is constructed, outputting the modulation wave voltage amplitude signal. Finally, the modulation wave phase signal and amplitude signal are combined to generate a pulse modulation wave signal. Thus, this invention can accurately lock the grid phase when the weak grid voltage contains harmonics and DC components, effectively improving the stable grid-connected operation capability of the grid-connected inverter under large disturbances.

This invention relates to the field of grid connection technology for new energy power units, and particularly to a method, system, storage medium, and processor for identifying control parameters of a grid-connected converter for new energy power units. The method of this invention establishes a high-frequency impedance model of the grid-connected system of the new energy power unit and determines the parameters to be identified, including the proportional coefficient and integral coefficient of the converter's inner current loop, as well as the control delay of the converter. By applying harmonic voltage disturbances at different frequencies, the harmonic currents of the unit at different frequencies are measured, thereby obtaining impedance values ​​at three different frequencies. These three impedance values ​​are input into the high-frequency impedance model of the grid-connected system of the new energy power unit, and the parameters to be identified are solved by solving the high-frequency impedance model of the grid-connected system of the new energy power unit. The model involved in this invention has a low order, and the control parameters of the converter's inner current loop can be obtained through only a small number of impedance tests and equation solving, featuring high identification efficiency and high accuracy.

This invention discloses an optimal incremental control method for a converter. The method involves acquiring the converter's output current and voltage in the dq coordinate system, and then calculating the converter's active and reactive power outputs. A control frequency signal is obtained through a phase-locked loop (PLL), and the control frequency signal is integrated to obtain a phase signal. The active and reactive power outputs of the converter are used as inputs to an incremental controller, which processes the data to obtain d-axis and q-axis current reference values ​​for the inner current loop. These reference values ​​are then input to the inner current loop to generate a modulation wave voltage amplitude signal. A drive signal is generated based on the modulation wave voltage amplitude and phase signal to control the converter. This invention eliminates the need for a pre-established precise system analytical model, fundamentally overcoming the control performance degradation caused by inaccurate model parameters or structural mismatches, and effectively improving the dynamic performance of the converter under complex power grid conditions.

The invention discloses a coordination control method, system and device for a multi-machine parallel SVG and a storage medium, and relates to the technical field of dynamic reactive compensation of a power system, and the method comprises the steps: employing a chain SVG circuit topological graph, constructing a direct-hanging SVG simulation model, and carrying out the simulation analysis to make a control strategy; a control strategy real-time verification platform is constructed to verify the control strategy, a communication conversion protocol of the SVG control system is converted into a real-time simulation communication adaptation protocol supported by the simulation system, and early-stage principle verification is completed; a rotating coordinate system PI double-closed-loop grid-connected control strategy is adopted, reactive current loop setting is generated, a coordination control strategy is executed in a multi-machine parallel connection scene, reactive hedging is restrained, and dynamic response is unified. According to the method, reactive current loop setting is generated by adopting a rotating coordinate system PI double-closed-loop grid-connected control strategy, and unified setting and consistent response with current inner loop rapid tracking and outer layer reactive target mapping as the core are achieved.

This invention discloses a charging and discharging control method, control system, and device for a dual-channel battery energy storage inverter. The method includes: detecting the DC bus voltage and comparing it with a target value to generate a bus voltage error signal; inputting the error signal into a voltage outer loop controller and outputting a total system current setpoint; acquiring the state of charge (SOC) values ​​of the first and second channels of batteries in real time; dynamically selecting a current distribution strategy: when both SOC values ​​are higher than or lower than the target SOC, a proportional distribution strategy is executed; when one SOC value is greater than the target SOC and the other is less than the target SOC, a forced equalization strategy is executed; and allocating the current setpoint as an independent current input to the corresponding inner current loop to generate a PWM signal to drive the switching transistor, so as to achieve proportional distribution to avoid overload in the same-direction state and forced equalization to achieve energy transfer in the reverse state, thereby extending battery life.

This invention relates to a current feedforward control method, device, and switching power supply. The control method includes: acquiring a first voltage signal characterizing the DC bus voltage, a second voltage signal representing the input voltage, a first current signal representing the input current, and a second current signal representing the load current; calculating a current inner loop reference quantity from the voltage outer loop; calculating the current feedforward quantity according to the power balance formula, and combining the fixed coefficient and efficiency in the current feedforward quantity expression into a constant; and setting the current inner loop reference quantity I... Udc and current feedforward quantity I f The superimposed values ​​serve as the reference for the inner current loop, which then adjusts the drive signal of the PFC circuit. It is then determined whether the PFC circuit satisfies |I| under full load. Udc -I f | <Set threshold: If yes, no constant adjustment is needed, control ends; otherwise, if I Udc >I f Then increase the constant and return to the drive signal adjustment step. If I Udc <I f The constant is then reduced and the process returns to the drive signal adjustment step. This invention can reduce the amplitude and duration of DC bus voltage fluctuations when the load changes.

This application relates to the field of industrial automation control and discloses a digital closed-loop controller for a flow-driven electric direct-drive valve. The controller includes a main control module, a signal acquisition circuit, a drive output module, and a current sampling circuit. The main control module acquires the temperature of the valve body and circuit board, calculates the core temperature of the coil based on an equivalent model of a thermal resistance network, and uses this temperature and the target pressure setpoint to obtain a feedforward control current through multi-dimensional lookup tables and linear interpolation to compensate for hysteresis characteristics. Simultaneously, the PID gain parameters are adjusted in real time based on the core temperature of the coil, and a feedback compensation current is calculated to suppress thermal decay. Finally, the feedforward and feedback currents are superimposed and used to control the drive coil via an inner current loop. This invention effectively solves the problems of thermal drift, hysteresis nonlinearity, and model parameter mismatch in a wide temperature range environment without embedding an internal temperature sensor, thus improving the control accuracy of the valve.

The invention discloses a hybrid RL-SSA-based photovoltaic grid-connected inverter controller parameter identification method, and the method comprises the following steps: S1, building a three-phase grid-connected power generation system simulation model, and recording the DC side voltage udc of an inverter, and the current inner loop control currents id and iq; s2, determining to-be-identified parameters kPu, kIu, kPi and kIi of the photovoltaic grid-connected inverter controller in combination with the control strategy; s3, using the to-be-identified parameters as a population by adopting an SSA algorithm, and performing division; s4, establishing an optimization state space of an RL-SSA algorithm by adopting a reinforcement learning thought according to the population characteristics; s5, designing an action space of the RL-SSA according to a greedy strategy; and S6, according to the current population diversity, the number of iterations and the fitness distribution condition, improving a reinforcement learning reward mechanism and performing optimization, and recording an optimization result of the RL-SSA as a final identification result of the parameter. According to the method, the unique advantages of the RL in the identification process are fully utilized, and the identification effect of the control parameters is remarkably improved through continuous interaction between the intelligent agent and the environment and strategy iterative optimization.

The invention discloses an eddy current shielding test device based on an alternating current internal resistance test, which comprises a switching device and a to-be-tested assembly, and is characterized in that the to-be-tested assembly comprises a current electrode and a shell detection electrode; the switching device is connected with the current electrode to form an internal current loop and is used for generating excitation current in the to-be-tested component; meanwhile, a shell detection electrode is connected to form a shell current loop for injecting compensation current into the to-be-detected component shell; the internal current loop is connected with the shell current loop through the switching device, so that a magnetic field generated by the shell current loop counteracts a magnetic field generated by the internal current loop, and eddy current interference generated by excitation current in an alternating current internal resistance test is inhibited. The device is used for shielding eddy current generated in the alternating-current internal resistance testing process of the blade type battery, and the accuracy of the alternating-current internal resistance testing process is improved.

The utility model discloses a control system for current sharing of parallel inverters, which comprises a plurality of parallel inverters and a voltage outer loop controller, each inverter comprises a bridge circuit consisting of switch tubes S1, S2, S3 and S4, and each inverter is provided with an independent current closed loop control unit. And the current closed-loop control unit comprises an independent current inner loop which is arranged in the inverter and is used for respectively controlling the current of each inverter. And dividing the current reference value calculated by the voltage outer loop controller into N equal parts as the current reference value of the current loop in the inverter. Closed-loop control is respectively carried out on the current of the plurality of inverters, so that the current sharing among the inverters is ensured.

This invention belongs to the field of inverter technology, specifically relating to a nonlinear control method for a three-phase voltage source inverter, including detecting inductor current I. Labc Detect the output voltage V oabc ; By transforming from the abc coordinate system to the αβ coordinate system, we obtain I Lαβ V oαβ ; Set the outer voltage loop parameter K2 and the inner current loop parameter K1; obtain the filter inductor current reference value through the outer voltage loop, input the current reference value into the inner current loop control, and obtain the inverter modulation signal S in the αβ coordinate. invx(x＝α,β) The modulated signal is transformed into an abc coordinate system as S. invz(z＝a,b,c) The invention outputs PWM drive signals for the inverter's switching devices via carrier modulation to drive the inverter to output three-phase AC power. This invention effectively solves the chattering problem caused by the sliding phase term in the current inner loop control, introduces a nonlinear control term, enhances the system's robustness, and enables the inverter to compensate for both low-order and high-order harmonic voltages.

This invention discloses a control method for a Vienna rectifier topology based on SiC power devices. First, a mathematical model of a three-phase Vienna rectifier is established; then, the expressions for the Vienna rectifier's midpoint voltage and current are derived; an inner current loop is designed; an outer voltage loop is designed; and finally, midpoint potential balance control is performed. This invention can reduce the size of the Vienna rectifier system, improve the power factor, and reduce system losses.

The invention belongs to the technical field of power system control, and particularly relates to an oil field well site direct current micro-grid source load storage control system and an energy storage current converter and alternating current bus current converter control method in the oil field well site direct current micro-grid source load storage control system. An energy storage system current converter adopts double closed-loop control of a voltage outer loop and a current inner loop, and a current reference value in the double closed-loop control is obtained by the following method: inputting a ratio of a bus voltage measured value and a reference value of an oil field well site direct current micro-grid and the reference value of the ratio into a linear expansion state observer to obtain an observation result; and inputting an observation result into a global fast terminal sliding mode controller to obtain a current reference value. The linear expansion state observer and the global fast terminal sliding mode controller are adopted for composite control, the method can adapt to the multi-load cooperation working condition of the direct-current microgrid source load storage system of the oil field well site, and the stability and robustness of the system are improved.

The invention belongs to the technical field of direct-current micro-grids, and particularly relates to an oil field well site direct-current micro-grid control system and a control method of an energy storage current converter of the oil field well site direct-current micro-grid control system. The energy storage converter adopts double closed-loop constant voltage control of a voltage outer loop and a current inner loop, a VDCM module is connected in series between current reference value inputs of the voltage outer loop and the current inner loop, and rotational inertia in the VDCM module is adaptively regulated and controlled based on a system state variable of an oil field frequent direct current micro-grid; the system state variables comprise a bus voltage change rate and a load starting signal; correspondingly, the self-adaptive regulation and control of the rotational inertia comprises the step of increasing the rotational inertia when the bus voltage change rate exceeds a set change rate threshold value or the load starting signal is a high-power load starting signal. The stability of the direct-current bus voltage can be improved, and transient change and oscillation are prevented.

The invention relates to a three-phase shift regulation and control method for a CLLC resonant converter, and the method comprises the steps: monitoring an input voltage, an output voltage and power in real time: obtaining an actual input voltage, an actual output voltage and an external input target output voltage through the sampling of a hardware sampling circuit, and measuring the actual output voltage and an output current; an external voltage loop calculates a voltage error, and a current reference is obtained through the voltage loop, so that the voltage of the load / battery is kept at a target value; an inner current loop calculates a current error, and a power control quantity and a second output are output through the current loop; actual input voltage is measured and enters a table look-up module through a gain block, a table look-up LUT is carried out to obtain three phase shift parameters, the three phase shift parameters are input into a PWM modulator, and a PWM waveform is generated; the output end of the PWM modulator is connected with the CLLC converter to realize stable output, the optimal phase shift angle combination can be determined in real time, so that the comprehensive efficiency of the CLLC resonant converter in a full working range is maximized, and the problem of control performance bottleneck in the prior art is solved.

The present invention discloses a nonlinear control method for an interleaved parallel Buck converter based on an extended state observer. The inner current loop adopts differential flat control, and the switching control law is obtained according to the state equation of the system. The outer voltage loop adopts global fast terminal sliding mode control, and the reference value of the inductor current of each phase is determined according to the sliding mode. The sliding mode control law does not contain a switching function, which reduces the difficulty of parameter adjustment. To further weaken the chattering caused by the sliding mode control, an extended state observer is used to estimate the total disturbance and compensate for the total disturbance. While ensuring the steady-state output and transient response speed of the system, the present invention realizes the current sharing control of each phase, and adopts the extended state observer to estimate the unknown total disturbance, so that the output can quickly follow the output expected value.

A DC-to-DC converter control method and system based on backstepping super-twisting, a device, and a storage medium are disclosed, the method including: constructing a state-space model of a DC-to-DC converter according to Kirchhoff's laws and a topological structure of the DC-to-DC converter; acquiring initial PWM wave control information by using a backstepping control algorithm in an inner current loop of the DC-to-DC converter according to the state-space model; processing the initial PWM wave control information by using a super-twisting sliding mode control algorithm in an outer voltage loop of the DC-to-DC converter based on the state-space model to obtain final PWM wave control information; and regulating an operation state of the DC-to-DC converter with the final PWM wave control information.

The invention discloses a multi-voltage feed-forward control method and system for a power grid support type inverter and a storage medium, and aims to introduce multi-voltage feed-forward control to solve the problem that oscillation and instability are easily generated between a following grid type power grid support type inverter and an inductive power grid, and perform error calculation and control of a power outer loop and a current inner loop according to a feed-forward value. According to the multi-voltage feed-forward control strategy provided by the invention, the problem of instability caused by an outer loop control link and a current inner loop control link can be solved at the same time, and the stability of the grid-following type voltage support type inverter can be greatly improved.

A control method and device for current-source static frequency converters (SSCs) applicable to synchronous condenser startup includes grid-side bridge control and machine-side bridge control. Grid-side bridge control employs a dual closed-loop control method (outer speed loop plus inner current loop) during SSC startup, controlling commutation based on grid-side voltage, machine-side bridge commutation status, and dual closed-loop output trigger angle. Machine-side bridge control, when the SSC is stationary, determines the thyristor sequence number triggered for the first time after the SSC is unlocked based on the SSC rotor position angle, providing the desired electromagnetic torque to the SSC. After the SSC drives the SSC to rotate, the machine-side bridge uses the machine terminal line voltage phase angle to determine the subsequent thyristor sequence numbers, providing the desired electromagnetic torque to the SSC and enabling smooth acceleration. This effectively improves speed control accuracy, reduces control complexity, and lowers motor startup failure rate.

This invention discloses a zoned control method for improving the transient stability of GFM-VSC, comprising: continuously monitoring the grid voltage amplitude and phase angle; calculating internal state parameters and voltage sag depth using droop control equations to initiate a zoned control strategy; dividing the effective operating region of the grid voltage using voltage vector geometric analysis based on current limiting constraints and grid voltage phase jumps; when a grid fault occurs, adaptively tracking the rated power angle during voltage phase disturbances using a LADRC controller to eliminate disturbances; performing real-time state judgment based on the effective operating region of the grid voltage, executing a virtual impedance switching strategy, and forcibly implementing steady-state fault current limiting by reconstructing reactive power reference values ​​in the voltage loop; and based on a voltage-current dual closed-loop control system, using phase-preserving amplitude limiting technology in the inner current loop to adjust the amplitude and phase of the reference current to suppress pulse current, thereby obtaining the final pulse width modulation voltage command.

The invention provides a matrix converter low-frequency side outer ring active power control method and a related device, and the method comprises the steps: judging the connection type of an AC side based on the collection of the operation scene data of the low-frequency side of a matrix converter, and starting an active power control process when the AC side is connected to a power grid; acquiring three-phase electrical data of the low-frequency side of the matrix converter, and performing coordinate transformation to obtain a positive sequence voltage component and a positive sequence current component; calculating actual active power based on the voltage component and the current component; performing deviation correction processing on the actual active power and preset target active power to obtain a correction signal, and performing feed-forward compensation processing based on the preset target active power to obtain a compensation signal; fusing the correction signal and the feedforward signal to generate a d-axis current control instruction signal; and driving a current inner ring based on the d-axis current control instruction signal to carry out active power adjustment on a low-frequency side outer ring of the matrix converter. According to the control method, the dynamic responsiveness and the operation reliability of the low-frequency side of the matrix converter are improved.

This invention discloses an active arc suppression method for generator stator grounding faults based on dual-loop quasi-PR control, comprising the following steps: S1. Monitoring the fundamental zero-sequence voltage and third harmonic voltage at the generator neutral point and terminals, and performing fault phase selection and location when a single-phase stator grounding fault occurs; S2. Calculating the fault winding potential based on the fault location results. E f And negative it – E f S3. Set the neutral point target compensation voltage; S4. Adopt a topology structure of cascaded H-bridge converters as active control devices, and establish a dual closed-loop control framework consisting of an outer voltage loop and an inner current loop; S5. Set quasi-PR control units for the fundamental and third harmonic components in the outer voltage loop and the inner current loop, respectively; S6. Control the output of the cascaded H-bridge converter to the target compensation voltage – E f A consistent compensation voltage is injected into the generator neutral point. This invention improves the voltage regulation accuracy and arc suppression speed during the active arc suppression process of the generator, thereby enhancing the safety and reliability of generator operation.

The invention discloses a control method, device and system for an energy storage converter. The control method at least comprises a virtual frequency modulation control loop, a virtual voltage regulation control loop and a voltage and current double closed loop. The virtual frequency modulation control loop comprises a frequency modulation link, an inertia link, a damping link and a damping power compensation link, and the virtual frequency modulation control loop is used for generating a first angular frequency; the virtual voltage regulation control loop comprises a voltage regulation link and a reactive power control link, and the voltage regulation control loop is used for generating a first voltage amplitude; the voltage and current double closed loop comprises a voltage outer loop and a current inner loop, and the voltage and current double closed loop is used for generating a modulation signal according to the first angular frequency and the first voltage amplitude; wherein when the energy storage converter works in a steady state, the damping compensation power generated in the damping power compensation link and the damping power generated in the damping link are the same in size and opposite in direction. According to the scheme, the primary frequency modulation characteristic can be improved, the influence of damping power on primary frequency modulation is eliminated, and the operation reliability of the energy storage converter is improved.