695 results about "Power electronics converters" patented technology

The invention discloses an energy management method for a photovoltaic energy storage system, and relates to the technical field of energy management, and the method comprises the steps: collecting the operation state and environment demand data of a photovoltaic module in real time, and transmitting the data to an edge computing device for primary processing; the edge computing device analyzes the operation state and the environment demand data in real time by using a lightweight machine learning model to generate prediction data; based on prediction data of the edge computing device, a deep reinforcement learning algorithm is adopted to train an intelligent agent, an optimal energy management strategy is learned, and a charging and discharging strategy of the power electronic converter is dynamically adjusted; and carrying out real-time monitoring on the system state snapshot data, and if a significant change which does not conform to prediction is monitored, re-evaluating the supply-demand balance state, and adjusting the working mode of the power electronic converter. The system integrates the Internet of Things and the AI technology, intelligently regulates and controls photovoltaic energy storage, optimizes energy management, improves efficiency and benefits, solves technical bottlenecks, and enhances system performance.

The invention discloses a driving control method of a DAB converter and related equipment, and relates to the technical field of power electronic converter control, and the method comprises the steps: calculating a voltage transformation ratio based on an input voltage and an output voltage through a current stress adjustment module, and calculating an output power based on the output voltage and an output current, substituting the voltage transformation ratio and the output power into a current stress adaptive minimization algorithm to solve an internal phase shift angle; meanwhile, through a PI controller, an external shift phase angle is adjusted based on a difference value between the instruction voltage and the output voltage; outputting the inner phase shift angle and the outer phase shift angle to a PWM modulation generator to generate a switching tube driving signal; the DAB converter is controlled by the driving signal to realize rated voltage output and current stress minimization, so that the efficiency and reliability of the converter are improved.

The invention discloses a modeling method of a fractional order LC type three-phase inverter, and relates to the technical field of modeling and control of power electronic converters. On the basis of a traditional integer order LC type three-phase inverter, an integer order LC type filter in the inverter is replaced by a fractional order LC type filter, so that a new fractional order inverter topology is constructed. On the basis of the topology, mathematical models under a three-phase static abc coordinate system and a two-phase rotating dq coordinate system are constructed. Based on the mathematical model, a voltage and current double-closed-loop decoupling control strategy of the fractional order LC type three-phase inverter is deduced. In addition, a traditional virtual synchronous generator control link is replaced by an FOVSG control link, and the stability of the FOVSG control link is analyzed through a small signal model. According to the invention, dynamic decoupling can be effectively realized according to the order of the fractional order LC filter. In addition, an adjustable order is introduced in the FOVSG control link, and the performance of the inverter is improved under different control requirements.

The invention provides an impedance scanning device based on network side voltage dynamic compensation under a three-phase voltage imbalance working condition, and relates to the technical field of new energy station power electronic converter topology and control, the device comprises a three-phase rectifier, a direct current bus capacitor, an inverter, a voltage compensation device, a frequency sweeping device, a circuit breaker and a series transformer part, the three-phase rectifier is connected in series with inverters of the voltage compensation device and the frequency sweep device, a secondary side of a series transformer of the voltage compensation device is connected in series with a network side, a secondary side of a series transformer of the frequency sweep device is connected in series with a grid-connected point, and a primary side of the series transformer is connected to the inverters and is coupled to a secondary side of the series transformer; according to the device, the power grid side voltage is rectified through the voltage compensation unit and is compensated to the grid side after being subjected to single-stage inversion transformation, voltage compensation is achieved through the energy of a power grid when the voltage is unbalanced, and an external energy source or an interference source does not need to be introduced. After compensation, the accuracy of the frequency sweeping result is obviously improved.

The invention relates to a multi-energy collaborative intelligent micro-grid control method, device and equipment and a medium. According to the method, a micro-grid frequency signal is collected in real time, the change rate of the micro-grid frequency signal is calculated, the inertia requirement of a system is accurately evaluated, the maximum virtual inertia capable of being provided by each unit is dynamically calculated in combination with the physical characteristics and operation constraints of each energy unit, and the system requirement and the unit capacity are dynamically matched through grey correlation analysis to generate an optimal distribution scheme. And then the special control models of all the units are driven to generate differentiated power regulation instructions, and finally power support is cooperatively executed through the power electronic converter, so that accurate matching and efficient cooperation of multi-energy virtual inertia capability are realized, the frequency stability of a high-proportion new energy power grid is remarkably enhanced, and the system performance is improved. The problems of resource allocation mismatch, poor control adaptability and the like in a traditional method are effectively avoided, and the dynamic safety of the system is guaranteed under the complex operation working condition.

The invention discloses a dual active bridge converter and a DC bias suppression method thereof, and belongs to the technical field of power electronic converters, and the method comprises the steps: carrying out the bilateral single-phase shift modulation according to a distribution coefficient p when the dual active bridge converter operates in a steady state; establishing an inductive current function model of the dual-active bridge converter considering the high-frequency link resistance; when a phase shift angle between the primary side and the secondary side of the dual-active bridge converter changes, according to circuit parameters of the dual-active bridge converter, an inductive current function model and a phase shift ratio before and after the change, a transient phase shift ratio is calculated and allocated to the primary side and the secondary side for bilateral single phase shift modulation. By introducing the transient phase shift ratio and the distribution coefficient and combining a bilateral phase shift control mode, transient direct current bias generated by transient inductive current and converter magnetic flux can be eliminated, excessive design of a magnetic element is avoided, and the ratio of any high-frequency link resistance value to a shift term can reach a stable state within a switching period.

The invention relates to a current reference quantity feed-forward compensation control method and system. The control method comprises the following steps: determining a current inductive current reference value of a triangular wave type power electronic converter; obtaining a PI control component based on the current inductive current reference value; subtracting the current inductive current reference value from the inductive current reference value of the previous period to obtain an inductive current reference value variable quantity; feedforward operation is carried out according to the inductance current reference value variable quantity and the working condition parameters of the triangular wave type power electronic converter, and a feedforward compensation component is obtained; and summing the PI control component and the feed-forward compensation component to generate a duty ratio so as to realize control of the triangular wave type power electronic converter. According to the current reference quantity feed-forward compensation control method and system provided by the invention, the tracking speed of the triangular wave type power electronic converter can be improved on the premise of not influencing the control precision of the triangular wave type power electronic converter.

The invention discloses a cooperative control system for an input-series output-parallel dual-active-bridge inverter, and relates to the technical field of power electronic converter control, an input voltage equalizing control IVSC loop is set for m-1 DAB sub-modules, and input voltage equalization of the DAB sub-modules is realized by adjusting phase shift angles of the sub-modules; an output voltage control OVC loop is set for the output DC bus voltage of the whole ISOP-DAB system to stabilize the DC bus voltage, a PIR controller is adopted in the OVC loop, and the resonant frequency is set to be twice of the fundamental frequency of the AC side, so that selective high gain is provided at the position, the frequency doubling fluctuation of the DC bus voltage is inhibited, and the frequency doubling fluctuation of the DC bus voltage is inhibited. According to the method and the device, the regulation quantity of the IVSC loop and the regulation quantity of the OVC loop are superposed to carry out cooperative control, so that the effective suppression of the frequency doubling fluctuation of the DC bus voltage and the automatic equalization of the power of each module are accurately realized on the premise of not increasing the hardware complexity.

The invention relates to the technical field of power electronic converters, and discloses a grid-connected inverter multi-parameter online setting method, system and device and a medium. The method comprises the following steps: establishing a circuit simulation model of the grid-connected inverter; output currents of the grid-connected inverter under different power grid impedance working conditions are obtained through the circuit simulation model, and target control parameters of the grid-connected inverter under different power grid impedance working conditions are obtained through iterative search by adopting a particle swarm optimization algorithm through the circuit simulation model; performing off-line training on the parameter reasoning model through the output current of the grid-connected inverter under different power grid impedance working conditions and the target control parameter under the corresponding power grid impedance working condition; acquiring an output current of the grid-connected inverter in real time, and inputting the output current acquired in real time into the trained parameter reasoning model to obtain a corresponding target control parameter; and on-line setting is performed on the control parameters of the grid-connected inverter through the target control parameters output by the parameter reasoning model, so that rapid setting can be realized.

A power electronics converter includes a substrate and a converter commutation cell including a power circuit. The power circuit includes at least one power semiconductor switching element and at least one capacitor. Each power semiconductor switching element is comprised in a power semiconductor prepackage. An electrical connection side of the respective power semiconductor prepackage is spaced apart in a z direction from the substrate so as to define a prepackage gap between the substrate and the electrical connection side. At least a portion of the prepackage gap is filled with an electrically insulating material having voids. A converter parameter σ defined as an insulation fill factor divided by a maximum void size is greater than or equal to 10 / mm. The insulation fill factor is defined as a cumulated volume of the voids subtracted from a volume of the electrically insulating material divided by the volume of the electrically insulating material.

Described herein is a method of operating a power electronic converter device for an electrical power conversion system. The power electronic converter device includes a converter circuit including an input side, an output side, a first converter, and at least one second converter. The second converter includes at least one floating cell with a DC intermediate circuit and semiconductor devices. The method includes: switching the semiconductor devices of the floating cell at switching instants determined with optimized pulse patterns or carrier-based pulse width modulation; determining a fundamental voltage component for the floating cell; and generating the fundamental voltage component in the actual voltage of the floating cell by modifying the switching instants, such that a voltage VC AF of the DC intermediate circuit is lying in a given reference voltage range for balancing the DC intermediate circuit of the floating cell.

The invention provides a voltage and current harmonic coordinated suppression method and system based on a power electronic converter, the method works in a typical scene of distributed power supply network construction and network-following hybrid control, and the method comprises the following steps: using extracted load current harmonic as a network-following converter harmonic control instruction to suppress load harmonic current; a harmonic virtual impedance method is adopted to adjust the grid-connected harmonic voltage of the grid-forming converter, so that the harmonic content of voltage and current is inhibited in a coordinated manner. According to the method, the equivalent power supply characteristics of network construction and network following are fully utilized, comprehensive treatment of the background harmonic voltage and harmonic current of the power grid is realized, and the network access electric energy quality of the grid-connected system under the weak network is improved.

The invention belongs to the field of power electronic converter control and design, and discloses a carrier modulation method and system for achieving accurate control over the neutral-point potential of a three-level inverter. The neutral-point voltage is kept in a relatively balanced state by detecting and correcting the voltage difference of an upper capacitor and a lower capacitor on the direct current side in time; and the distortion of the output voltage at the alternating current side caused by large fluctuation of the neutral-point potential is reduced or avoided. A midpoint potential correction link is introduced while the advantages of a conventional SVM or carrier modulation are not damaged; and when the neutral-point potential deviates, the zero-sequence voltage is automatically injected or a proper switching vector sequence is selected to compensate, suppress harmonic waves and reduce the distortion degree, so that the waveform quality of the output voltage is improved.

The invention relates to an MMC (Modular Multilevel Converter) optimal zero-sequence signal calculation method for an overload operation demand, which belongs to the field of power electronic converter signal modulation, and comprises the following steps: constructing an optimal zero-sequence signal calculation operation domain; establishing an optimal zero sequence signal solving mathematical model; continuously iterating the active power and the reactive power, inputting the optimal zero-sequence signal to solve the mathematical model, solving to obtain a plurality of groups of maximum modulation signal margin values Mar, amplitudes and phase angles of corresponding zero-sequence signals, namely amplitudes and phase angles of optimal zero-sequence signals, outputting and recording, and respectively forming an OPA3 (P, Q) table and an OPAlf3 (P, Q) table; and fitting the table by adopting a function fitting mode to obtain a final fitting functional expression which is used for subsequently and quickly calculating the amplitude and the phase angle of the optimal zero-sequence signal. According to the invention, the operation time of modulation signal overmodulation caused by overload operation of the MMC can be greatly reduced, and the problem that the service life of a switching device is shortened due to modulation signal overmodulation is reduced.

The invention discloses a two-degree-of-freedom prediction control method of an LCL filtering type three-phase grid-connected inverter system, and belongs to the field of power electronic converter control. A prediction control reference instruction is obtained by sampling parameters of inverter side current, capacitor voltage, network side current and power grid voltage at the moment k, and a continuous and discrete model of an LCL filtering type three-phase grid-connected inverter system is established; designing a control function based on a grid-side current reference tracking error and a gradient thereof, and establishing a prediction model; constructing a prediction cost function based on a control function, and obtaining a prediction control reference instruction by using a minimum value of the prediction cost function; and determining an optimal voltage vector and an action duty ratio according to the prediction control reference instruction, generating a control pulse signal according to a symmetrical five-section pulse mode, and acting on each switching tube in the inverter to realize prediction control of the LCL filtering type three-phase grid-connected inverter system. The method is simple in step, convenient to use, constant in switching frequency and good in stability.

The invention discloses a control method for fast switching from heavy load to light load of an LCC resonant converter, and relates to the technical field of power electronic converter control. The method comprises the following steps: S1, building an LCC resonant converter; s2, monitoring load current in real time, and identifying a load abrupt change signal; s3, calculating coordinates of an intersection point of the current working point and the target light load trajectory according to the state trajectory model; and S4, triggering a switch tube advanced turn-off instruction at the switching point, and switching the driving system to a light load mode along the transition track. According to the invention, a specific switching period is introduced during frequency switching, so that the resonant converter can be rapidly and stably switched from a heavy-load working mode to a light-load working mode. According to the switching mode, the voltage overshoot phenomenon during load sudden change can be effectively suppressed, the response time can be shortened, and the dynamic response performance of the resonant converter can be greatly improved. Compared with a traditional scheme, the system stability is improved, and the power loss is reduced.

The invention discloses a variable frequency phase shift control DAB type single-stage inverter reactive power control method, system and device and a medium, and belongs to the technical field of power electronic converter control, and the method comprises the steps: setting a reactive power instruction as zero; when the reactive power instruction changes, the active power instruction and the reactive power instruction at the current moment are decomposed into a direct-axis current reference value and a quadrature-axis current reference value respectively; comparing the reference value with an actual sampling value, calculating an error compensation amount by using a PI controller, and determining the amplitude and phase of the AC side current according to the compensation amount; according to the amplitude and the phase of the voltage and the current, a DAB frequency conversion phase shift control curve is calculated; and generating a PWM (Pulse Width Modulation) signal according to the frequency conversion phase shift control curve obtained by calculation, wherein the PWM signal is used for driving a DAB inverter to carry out power transmission. According to the invention, on the premise that no extra hardware circuit is introduced, dynamic adjustment and accurate control of the instantaneous reactive power of the AC output side can be realized.

A device and method for managing power transmission to a power grid from a Hybrid Grid Connected System (HGCS) is presented. The HGCS includes a plurality of energy resources, including of solar photovoltaic cells (PV), wind power generation, a battery energy storage system (BESS) and a fuel cell system paired with an electrolyzer. Energy sources are connected by a DC-link to a power electronic converter which supplies power to the power grid. A controller is configured to calculate the total power, maximize transmission of power to the power grid from the primary sources, supply the net power to the power grid from the fuel cell system and use the power generated by the PV system and the wind power system for charging the BESS and powering the electrolyzer system based on the relative state of charge of the BESS and the voltage of the DC-link.

A power electronics converter includes a multi-layer planar carrier substrate and a converter commutation cell including a power circuit. The power circuit includes at least one power semiconductor switching element. Each power semiconductor switching element is included in a power semiconductor prepackage. One or more terminals of the power semiconductor switching element are connected to at least one conductive layer of the multi-layer planar carrier substrate at an electrical connection side of the power semiconductor prepackage. The electrical connection side is spaced apart in a z-direction from the carrier substrate by a prepackage gap. A peak rated power output of the power electronics converter is greater than or equal to 25 kW, and a converter parameter θ, which is defined as a size in the z-direction of the prepackage gap divided by a maximum electric field strength in the prepackage gap, is less than or equal to 300 pm2 / V.

The invention belongs to the technical field of high-frequency planar transformers, and relates to a butterfly-shaped planar transformer with a twisted primary side and an anti-coupling secondary side and a switching power supply. The winding comprises a primary winding and a secondary winding; the magnetic core is of a four-core-column butterfly-shaped structure, and the secondary winding and the primary winding respectively surround two core columns in the center of the magnetic core; the winding directions of the secondary winding current around the two middle columns of the magnetic core are the same; the primary winding is positively coupled with one secondary winding and reversely coupled with the other secondary winding; according to the two-core-column matrix type transformer, the problem that magnetic saturation is caused by the magnetic flux of direct-current magnetic bias at the connecting part of the transformer is solved, so that the two-core-column matrix type transformer can be applied to a switching power supply with direct-current magnetic bias and a power electronic converter; compared with a traditional scheme, the efficiency and the power density of the transformer are remarkably improved.

The invention belongs to the technical field of power electronic converter control, and discloses a control method of a grid-forming type doubly-fed asynchronous wind power generation system with power control capability, which comprises a control process of a rotor-side converter and a control process of a grid-side converter, and is characterized in that the rotor-side converter forms a grid-forming type characteristic at a motor stator winding port, and the grid-side converter forms a grid-forming type characteristic at a motor stator winding port; the energy injected into the direct current bus capacitor is controlled; the grid-side converter maintains the input and output energy balance of the DC bus capacitor so as to control the voltage of the DC bus capacitor to be constant; the control process of the rotor side converter comprises a frequency support control loop, a power control loop, a voltage and current inner loop and pulse width modulation control, and the control process of the grid side converter comprises a direct current voltage control loop, a reactive power control loop, an alternating current control loop and pulse width modulation control. According to the invention, the capability of controlling the output power can be provided while the network construction type power dynamic index is realized.

A electrical power system comprises: an electrical machine operable to output AC; a DC electrical network; a power electronics converter connected between the AC output of the electrical machine and the DC electrical network and including a plurality of transistors and associated diodes connected in parallel with the transistors; and a controller configured to control switching of the transistors of the converter so that, during normal operation of the electrical power system, the converter rectifies the AC output of the electrical machine to supply the DC electrical network with DC electrical power. The controller is further configured, responsive to a determination to the effect there is a fault in the DC electrical network, to control a voltage source, to inject a voltage to bias the diodes of the converter, and to control the switching of the transistors to control a level of current supplied to the faulted DC electrical network.

The invention discloses a power distribution network voltage double-layer optimization method and device, and belongs to the technical field of power system control. A plurality of nodes of the power distribution network system are connected with a photovoltaic power generation system or a capacitor bank. The method comprises the following steps: acquiring input data of the plurality of nodes in the power distribution network system; optimizing the mechanical tap gear of the transformer and the switching group number of the capacitor group by taking the minimum line loss as the target and taking the condition that the voltage of the power distribution network system is not out of limit as the constraint; according to the mechanical tap gear and the switching group number of the capacitor bank, with the highest new energy consumption rate, the minimum operation cost and the minimum line loss as targets, the compensation capacity, the energy storage charging and discharging power and the compensation transformation ratio of the power electronic converter of the STATCOM are optimized; and configuring the power distribution network system under the condition that the voltage of the power distribution network system does not exceed the limit. According to the method, the voltage out-of-limit problem caused by photovoltaic backward flow is solved, and the voltage quality of the power distribution network is improved.

The invention discloses an energy storage converter predictive current control method based on data driving model self-learning, and belongs to the technical field of power electronic converter control. The energy storage converter is a half-bridge bidirectional DC-DC converter, and the method comprises the following steps: collecting the state quantity of the energy storage converter through a sensor in each control period, forming a data driving prediction model constructed by an input vector input neural network online parameter identification module, and outputting an initial duty ratio prediction value; constructing a value function, performing online optimization on an initial value through a gradient descent method to obtain a final optimal duty ratio, and simplifying a scene to directly use the initial value; comparing the optimal duty ratio with a carrier wave to generate a PWM (Pulse Width Modulation) signal to drive a power switch tube; actual inductive current is collected, an ideal duty ratio enabling the value function to be minimum is reversely solved to serve as a supervision signal, and the model weight is trained and updated online through a sample. The technical problem that traditional continuous set model predictive control depends on an accurate mathematical model is solved.

The invention discloses a wind-solar complementary hydrogen production system and method based on alkaline electrolytic water hydrogen production. The system comprises a photovoltaic power generation unit, a wind power generation unit, a storage battery energy storage unit, an electrolytic hydrogen production unit, a load and a power electronic converter. The photovoltaic power generation unit is electrically connected with the alternating current bus through an AC / DC converter, the wind power generation unit is electrically connected with the alternating current bus through an AC / AC converter, and the alternating current bus is connected with a superior power distribution network through a transformer; the storage battery energy storage unit is electrically connected with the alternating current bus through the AC / DC converter, the load is electrically connected with the alternating current bus through the AC / AC converter, and the electrolytic hydrogen production unit comprises an electrolytic bath, a compressor and a hydrogen storage tank; the problem that a single AEL technology or a PEMEL technology cannot give consideration to response speed and cost is solved, composite hydrogen production is achieved based on the constructed wind-solar complementary hydrogen production system, flexible absorption of wind-solar resources is achieved, and the hydrogen production cost of the system is reduced on the basis of improving the hydrogen production amount of the system.

The invention relates to the technical field of intelligent control of power electronic converters and induction heating, in particular to an intelligent control system of a medium-frequency power supply, which comprises a data acquisition module configured to acquire end-side voltage data and end-side current data of power conversion hardware in real time; the feature extraction module is configured to receive the end-side voltage data and the end-side current data and extract broadband waveform distortion features; the state evaluation module is configured to receive the broadband waveform distortion characteristics and calculate a model trust entropy value based on the broadband waveform distortion characteristics; the self-adaptive control module is configured to receive the model trust entropy value, trigger a second control mode to generate a second switch instruction and send the second switch instruction to the power conversion hardware; the model trust entropy represents a prediction deviation degree of a preset robust control model to the current real physical state of the power conversion hardware; according to the invention, the problem of insufficient perception of fine-grained service parameters in the background technology is solved.

Examples described herein provide a circuit that includes a power electronics converter disposed in a vehicle, the power electronics converter to receive alternating current (AC) electrical power from an AC grid source and to provide AC electrical power to an AC load external to the vehicle. The power electronics converter includes an AC-AC converter that includes a rectifier and an inverter, the rectifier being electrically connected to the inverter by a direct current (DC) link. The circuit further includes an on-board charging module electrically connected to the power electronics converter and a battery disposed in the vehicle. The power electronics converter provides vehicle-to-load functionality by providing, to the AC load, AC electric power as an output of at least one of a 120 Vac output or a 240 Vac output.

The invention provides a power electronic converter multi-task hardware-in-the-loop test method and system based on electric heating real-time simulation. The method comprises the following steps: establishing a power electronic converter circuit model; constructing a power semiconductor thermal network model; establishing an electric heating real-time simulation model of the power electronic converter through a loss calculation module and an electric parameter correction module; solving an electric heating real-time simulation model of the power electronic converter; and establishing a multi-task hardware-in-the-loop test platform based on the electric heating real-time simulation model, and carrying out multi-task hardware-in-the-loop test. Different from a traditional hardware-in-loop test, the method can perform multi-task hardware-in-loop test on various strategies of closed-loop control, thermal management, device protection, fault prediction, health management, fault-tolerant control and the like of the power electronic converter based on the electric heating real-time simulation model of the power electronic converter. According to the invention, comprehensive, efficient, safe and low-cost testing can be carried out on the converter, and the research and development period of the power electronic converter is shortened.

The invention relates to the technical field of power electronic converter control, in particular to an LLC converter dynamic response capability optimization control method based on a neural network, and the method comprises the steps: building an LLC converter dynamic response mathematical model based on a frequency conversion modulation strategy; optimizing the dynamic response process of the LLC converter during load switching by selecting a differential evolution algorithm and combining the mathematical model, and collecting k groups of frequency data with optimal LLC dynamic performance during load switching; training a pre-constructed neural network model by taking the collected k groups of frequency data with optimal LLC dynamic performance for load switching as training data; and applying the trained neural network model to an LLC converter controller to realize optimization of a dynamic response process. According to the invention, the LLC converter has better dynamic response capability in the load switching process, so that the LLC converter can stably and quickly reach a new steady state.

The invention provides a wind turbine generator grid-connected broadband oscillation power grid simulation method, system and device and a medium, and belongs to the technical field of power system new energy grid connection, and the method comprises the steps: carrying out the frequency sweeping of a network side part of a physical wind turbine generator grid-connected system, and obtaining a full-band dq impedance characteristic curve; performing segmentation processing on the full-band dq impedance characteristic curve according to frequency; performing rational function fitting on the dq impedance characteristic curve of each frequency band by using a least square method, and enabling the network side part of the physical wind turbine generator grid-connected system to be equivalent to an RLC branch; constructing an impedance circuit, a main circuit and a signal processing module for each frequency band, and completing the construction of a broadband oscillation working condition simulation circuit; and the broadband impedance dynamic characteristics of the physical wind turbine generator grid-connected system are reproduced through the broadband oscillation working condition simulation circuit, so that the grid-connected stability of the physical wind turbine generator is detected. According to the invention, the simulation precision of the power grid simulator based on the power electronic converter topology is prevented from being limited by switching frequency and control precision.