3742 results about "Phase currents" patented technology

The invention relates to the technical field of power system fault monitoring, and discloses a 10kV voltage transformer ground fault real-time monitoring method and system, and the system comprises a ground fault data collection module, a waveform distortion analysis module, a transient signal detection module and the like. Three-phase current, zero-sequence current and voltage waveform data are collected, a current harmonic component proportion, a zero-sequence current high-frequency transient energy value and the like are analyzed, a fault type is determined by combining a phase difference, and a fault position is positioned according to topological parameters and line impedance. And the temperature of the grounding down lead can be monitored, and the fault probability is evaluated and the threshold value is dynamically adjusted by machine learning. According to the invention, real-time accurate monitoring can be realized, fault types and positions can be accurately diagnosed, potential hidden dangers can be comprehensively monitored, the intelligence of a monitoring system is improved, the operation and maintenance cost and risks are effectively reduced, and safe and stable operation of the 10kV power distribution network is ensured.

The invention discloses a power distribution management system of an intelligent charging pile, and belongs to the technical field of electric vehicle charging facilities and intelligent power grids. The load prediction module carries out space-time alignment fusion on historical data and real-time monitoring data to generate a power distribution demand prediction value, and the edge calculation controller executes a model prediction control algorithm based on multi-source data to generate a real-time control strategy containing relay time sequence parameters and a capacitance compensation scheme. And the dynamic power distribution adjustment module executes strategy parameters through the solid-state relay array and the parallel compensation capacitor bank. Self-adaptive adjustment of the power distribution network is achieved through a real-time monitoring-prediction-optimization closed-loop control mechanism, the harmonic content of the power grid is effectively reduced, the energy distribution efficiency of the charging pile group is improved, and the method is suitable for intelligent electric energy management of public charging stations and other scenes.

The invention relates to the technical field of motor control, and discloses a control method and system of a permanent magnet direct current brushless slotless motor. The method comprises the following steps: performing temperature compensation and signal filtering on voltage data of a Hall sensor to obtain rotor position information and temperature characteristic data; performing magnetic field intensity dynamic compensation calculation according to the rotor position and the temperature data to obtain magnetic field intensity parameters; adjusting the amplitude and phase of the three-phase current according to the magnetic field intensity parameter, and generating a current control quantity; extracting and compensating a harmonic component to obtain a torque smooth control instruction; all losses are calculated and optimized, and efficiency optimization parameters are generated; and performing feature extraction and anomaly judgment on the operation parameters, and outputting a protection control strategy. Accurate detection of motor position signals, stable control of torque, optimal control of loss and real-time monitoring and protection of abnormal states are achieved under the high-temperature working condition, and therefore stable operation and the service life of the motor under the high-temperature environment are guaranteed.

The invention relates to the technical field of electrical variable measurement, in particular to a frequency converter fault detection method and system, and the method comprises the steps: obtaining A-phase current data, temperature data and torque data of a frequency converter at each collection moment; obtaining each current sub-sequence, determining the cycle difference of the current based on the dispersion degree of the distribution condition of the current data in all the current sub-sequences, and determining the waveform change value of the current by combining the difference of the corresponding torque data between each screened current sub-sequence and the adjacent current sub-sequence; respectively determining fundamental frequency indexes of the normal current data and the current data to be detected; determining a deviation value of the current; the temperature rising speed, the stability condition when the temperature reaches the maximum value and whether the rapid temperature rising is caused by load changes or not are analyzed, and the abnormal temperature rising value of the temperature is determined; and performing fault detection on the frequency converter. The invention aims to improve the open-circuit fault detection precision of the frequency converter.

The invention provides a power distribution network line fault testing and positioning method based on optical fiber pulse transmission, and relates to the technical field of power distribution networks, and the method comprises the steps: obtaining a phase voltage signal, a phase current signal and an optical fiber transmission signal of a power distribution network line, and judging a fault through wavelet transformation; when a fault exists, probe light is generated by using a narrow linewidth laser, a scattering signal is obtained after modulation of a Bragg grating array, and gain adjustment and coherent demodulation are performed on the scattering signal to determine a mutation point; based on the catastrophe point, a reflection signal is obtained through bidirectional reflection measurement, and the fault position is determined through combination of a group velocity dispersion equation and self-adaptive multi-stage dispersion compensation. Through photoelectric joint detection and multi-stage signal processing, the accuracy of fault positioning is improved, rapid and accurate positioning of the power distribution network fault is realized, and the method has relatively strong anti-interference capability and environmental adaptability.

The invention relates to the technical field of inverter control, and discloses an inverter output power control method and device, equipment and a storage medium. The method comprises the following steps: performing power frequency fundamental wave extraction and multi-band band-pass filtering on acquired voltage and current sampling data; performing phase compensation, first coordinate transformation and positive and negative sequence decoupling operation on the filtered fundamental wave principal component data; on the basis of a synchronous phase angle and a power grid fundamental wave frequency obtained by positive and negative sequence decoupling operation, carrying out second coordinate transformation, moving average and harmonic power delay difference operation on three-phase current and voltage data of an alpha-beta coordinate system; performing multi-level power calculation, power capacity distribution, error characteristic evaluation and decoupling operation on the inversion fundamental component and the inversion harmonic component subjected to the difference operation; and performing output signal modulation on the inversion power control quantity of the decoupling operation based on the fundamental wave synchronization phase angle, and generating a power control result. According to the invention, the control performance of the inverter on the output power in actual operation is improved.

The embodiment of the invention discloses a midpoint potential control method based on a diode clamping type three-level grid-connected inverter and a related device. The method comprises the following steps: generating an initial three-phase modulation wave through a current loop closed-loop control method according to a collected three-phase current value and a three-phase voltage value of a power grid side of the diode-clamped three-level grid-connected inverter; according to an initial modulation waveform generated by the initial three-phase modulation wave, a three-phase current value and an acquired voltage value of a voltage dividing capacitor at the direct current side of the diode clamping type three-level grid-connected inverter, calculating a zero-sequence component required by neutral-point potential balance; superposing a zero-sequence component required by neutral-point potential balance with the initial modulation waveform to obtain a final modulation wave; and generating a driving signal matched with each phase of bridge arm in the diode clamping type three-level grid-connected inverter according to the final modulation wave. By adopting the invention, the neutral-point voltage can be balanced, the distortion of the output waveform at the alternating current side is reduced, the voltage stress of the device is reduced, and the service life of the power device is prolonged.

The invention discloses a multi-end line pilot protection method and system based on time domain model identification, and relates to the technical field of electrical engineering, and the method comprises the steps: obtaining a three-phase voltage sampling value, a three-phase current sampling value and a switching value of each end of a multi-end line; judging whether each end of the multi-end line meets a protection starting condition or not; if yes, differential voltage variation and differential current are calculated, and correlation coefficients of the differential voltage variation and the differential current are calculated; judging whether the correlation coefficient is within a preset fault threshold range or not; if the correlation coefficient is not within the preset fault threshold range, determining that the multi-terminal line has an external fault, and enabling the protection device not to act; and if the correlation coefficient is within a preset fault threshold range, determining that the multi-terminal line has an internal fault, and enabling the protection device to act to remove the fault. According to the invention, the influence of capacitive current and a power electronic power supply on pilot protection performance is overcome, the operating characteristics of a relay protection device are improved, and safe and stable operation of a power system is ensured.

The invention discloses an electric energy metering method under power grid waveform distortion, and particularly relates to the technical field of electric energy metering. The problems of false triggering of an energy compensation mechanism, metering deviation and electricity price settlement risks caused by zero-sequence current or false phase drift easily generated in a multipoint grounding or grounding fault power system in the prior art are solved. According to the anomaly identification and control method integrating zero-sequence current frequency domain characteristic analysis and three-phase phase deviation trend consistency judgment, the false phase deviation state is accurately identified through synchronous sampling, frequency domain analysis and trend consistency evaluation of three-phase voltage, three-phase current and neutral line current, and the false phase deviation state is accurately identified. The error compensation behavior is shielded in real time, the fundamental wave power metering mode is switched to, the electric energy metering accuracy is guaranteed through an error backtracking correction mechanism after recovery, and the anti-interference capability and metering reliability of the electric meter under complex working conditions are effectively improved.

Embodiments of this invention discloses a split-phase output power adjustment system, adjustment method, and storage medium in a low voltage transformer area. The system includes adjustment power supplies, split-phase power adjustment modules, sub-controllers, a main controller. The adjustment power supplies connected to the split-phase power adjustment modules, and total power P of the adjustment power supplies complying with a relationship as follows: P=Pt=PG1+PG2+ . . . . PGn; wherein Pt is power required to comply with three-phase current unbalance adjustment of a distribution transformer, PG1, PG2, . . . PGn is power generated by each of the adjustment power supplies to compensate three-phase current unbalance in a transformer area; wherein the split-phase power adjustment modules are connected to lines of three phases A, B, and C and a neutral line N in the transformer area; wherein the sub-controllers are connected to the adjustment power supplies, and the sub-controllers communicate with the main controller to control power generated by each of the adjustment power supplies, so as to compensate the unbalanced three-phase current in the transformer area. Coordinated adjustment of multiple distributed power supplies realizes precise control of three-phase imbalance in the transformer area, which reduces line loss and improves power quality.

The invention relates to the technical field of three-phase current data processing, in particular to an electric energy quality intelligent monitoring method and system for a four-fusion integrated terminal. The method comprises the following steps: acquiring a current sequence and a monitoring phase corresponding to each phase line; calculating the suspected abnormal degree of the current monitoring point in the current sequence of the monitoring phase, and judging whether the current monitoring point is an abnormal monitoring point or not; if the current monitoring point is an abnormal monitoring point, acquiring a continuation curve; calculating a continuation distribution characteristic value of the abnormal monitoring point according to each data point in the continuation curve; correcting the continuation distribution characteristic value based on the distance between trough points of the crest of the continuation curve and the height of the crest to obtain a corrected continuation distribution characteristic value; obtaining the current abnormal degree of the abnormal monitoring point based on the suspected abnormal degree of the abnormal monitoring point and the corrected continued distribution characteristic value; and judging whether the electric energy quality is abnormal according to the current abnormal degree. According to the invention, the electric energy quality of the four-fusible integrated terminal can be accurately monitored.

The invention provides a fault ride-through control method and a fault ride-through control system for a grid-forming converter, which are characterized in that the current of the grid-forming converter under an asymmetric fault is controlled by adopting a negative-sequence current reference generation strategy aiming at an inner ring of a controller, and negative-sequence reactive current is injected into a power grid; adopting a partial sequence current amplitude limiting strategy to control the maximum phase current amplitude of the injected asymmetric current not to exceed an amplitude limiting value; controlling the boundary of an active reference value by adopting an active reference value amplitude limiting strategy for an active synchronization ring; a synchronous damping link is adopted to enhance damping in power angle swing; for a reactive voltage loop, a reactive voltage variable coefficient control strategy is adopted to control the output of the maximum reactive current; and an internal potential locking strategy is adopted to suppress overvoltage. According to the invention, negative-sequence reactive power is provided, and overcurrent of each phase is avoided; the power angle characteristic is improved, and the transient stability is improved; stable transient voltage support is provided in a current output capability range; and after the fault is recovered, the voltage of the converter grid-connected point is smoothly recovered.

The invention relates to the technical field of simulation testing, in particular to a motor simulator and a testing system. The motor simulator comprises a sampling module, a communication interface, a first processing module and a load module. The input end of the load module receives three-phase voltage and three-phase current input by the MCU module, and the output end of the sampling module is connected with the input end of the first processing module through a communication interface; the sampling module collects the three-phase voltage output by the output end of the MCU to obtain a three-phase voltage signal, and transmits the three-phase voltage signal to the first processing module through the communication interface; the first processing module is configured with a motor model, and the first processing module is configured to process the three-phase voltage signal based on the motor model to obtain an output signal and output the output signal to the upper computer and the MCU module; the motor model represents the corresponding relation between the input voltage of the motor and the output signal of the motor. By adopting the method, the MCU module can be tested in the absence of a real motor.

The invention relates to a tiny fault detection method for a rotary transformer of a vehicle driving motor. The method comprises the following steps: acquiring a three-phase current measured value of a motor, a rotating speed measured value of a motor rotor and a position angle measured value; converting the three-phase current measured value of the motor into a fixed coordinate system through coordinates to obtain a two-phase current measured value; obtaining a two-phase current estimated value, a rotating speed estimated value of the motor rotor and a position angle estimated value output by the fault detection observer, comparing the two-phase current estimated value, the rotating speed estimated value of the motor rotor and the position angle estimated value with the two-phase current measured value, the rotating speed measured value of the motor rotor and the position angle measured value, and calculating to obtain an evaluation function value; whether the evaluation function value exceeds a pre-configured threshold value or not is judged, and if yes, it is judged that the rotary transformer has a fault. Compared with the prior art, the method has the advantages that the influence of the fault can be distinguished from the uncertainty and noise of the system, so that the detection precision is improved.

The invention relates to the technical field of power electronics, the embodiment of the invention provides an enhanced network construction type SVG control method and system for suppressing broadband oscillation, the method comprises a network construction type control process and an additional damping control process, and the network construction type control process at least comprises: based on a direct-current voltage and frequency loop and an alternating-current voltage and amplitude loop, the additional damping control process is carried out; generating a virtual internal potential; generating a three-phase current instruction and a modulation wave based on the virtual internal potential, the virtual impedance and the fast current inner ring; based on the modulation wave, a converter trigger pulse signal is generated and transmitted; the additional damping control process at least comprises the following steps: detecting an oscillation frequency point based on a full-band scanning algorithm; extracting an oscillation frequency point, and generating an oscillation voltage without phase shift; virtual impedance is adjusted according to the impedance amplitude and the phase relation; and correcting negative damping based on the adjusted virtual impedance.

A motor controller for pulse heating of a power battery. The motor controller includes an inverter circuit, the inverter circuit includes three switching transistor bridge arms, two ends of each switching transistor bridge arm are respectively configured to connect to positive and negative electrodes of the power battery through a direct current bus, and bridge arm midpoints of the three switching transistor bridge arms are separately configured to connect to a three-phase winding of a motor. The bridge arm midpoints of the three switching transistor bridge arms are configured to output a three-phase current, the three-phase current is used to generate a pulse alternating current on the direct current bus, and the pulse alternating current is used to heat the power battery. A current of each phase of the three-phase current is a unipolar triangular wave, and a sum of the three-phase current is zero.

The invention belongs to the technical field of low-voltage distribution cable fault identification, and particularly relates to a method for judging a series arc fault of a low-voltage distribution cable based on disturbance current characteristics, which comprises the following steps of: S1, acquiring current data of three-phase current of the cable; s2, analyzing the similarity of the current waveforms of the adjacent current periods by adopting a Pearson correlation coefficient PCC, and judging whether the cable has current disturbance or not; s3, when it is judged that current disturbance occurs, intercepting current data of a disturbance starting point and a plurality of current periods after the disturbance starting point, and recording the current data as disturbance current; calculating the time-frequency domain characteristic quantity of the intercepted disturbance current; and S4, inputting the time-frequency domain characteristic quantity of the disturbance current into a preset fault identification model, carrying out detection and identification on a cable series arc fault, and judging whether the fault causing current disturbance is the series arc fault or not. According to the method, the low-voltage distribution cable series arc fault can be efficiently, accurately and timely monitored and identified, and the safety and stability of a power system are improved.

The invention provides a control method and device for a network-forming type energy storage converter, and belongs to the field of energy storage converter control. The method comprises the following steps: acquiring three-phase current and three-phase voltage of a grid-connected point of a target network-building type energy storage converter; according to the three-phase current and the three-phase voltage, determining active output power, reactive output power, and resistance and reactance of a power grid to which the target network-forming type energy storage converter belongs; based on the resistance and the reactance, outer ring self-adaptive parameters are calculated; wherein the outer ring adaptive parameter is used for performing VSG control; and according to the outer-loop adaptive parameter, the three-phase current, the three-phase voltage, the active output power and the reactive output power, controlling the target network-forming type energy storage converter. According to the invention, the active control strategy and the reactive control strategy in VSG control are improved based on the outer-loop adaptive parameters, so that the problem of coupling between the damping coefficient and the primary frequency modulation coefficient is solved, and the situation that the control performance is reduced and unstable due to the change of the impedance of the power grid is avoided.

A method for testing sheath impedance in a high-voltage cable cross-bonding system. Three-phase current data and three-phase grounding circulating current data from a first cable body segment and a last cable body segment in cross-bonding units, and three-phase current data, three-phase grounding circulating current data, and three-phase induced voltage data from a cable body at a cross-bonding box are detected and collected, thereby directly calculating three-phase sheath impedance of the three cable segments and determining whether the three-phase sheath impedance is abnormal (step 5), thus determining whether the tested cross-bonding units have a defect. The present invention involves a simple operation, achieves an accurate testing result, and can achieve energized testing without an external excitation source. By performing real-time testing on the cross-bonding units and calculating the sheath impedance of the three cable segments in the cross-bonding units in real time, the states of the cross-bonding units can be determined in real time, which makes it possible to detect a cable fault immediately, thereby preventing a loss caused due to the cable fault.

The invention relates to the technical field of electrical variable measurement, in particular to a rolling mill speed reducer monitoring and diagnosing system based on multi-source information fusion, which comprises an electrical parameter signal acquisition module for acquiring continuous readings of three-phase voltage and three-phase current of a rolling mill driving motor and synchronizing the readings. According to the method, the three-phase voltage and current data of the rolling mill driving motor are synchronously acquired, and the amplitude and phase are calibrated, so that a more accurate calibration electrical measurement set is obtained, and error propagation in a signal acquisition stage is effectively avoided; using the calibrated electrical data to directly calculate instantaneous input electric power, deducting motor loss to obtain an accurate motor shaft power sequence, and then using a Fourier transform method to extract key harmonic characteristics in a shaft power spectrum; and meanwhile, band-pass filtering and Hilbert transform analysis are carried out on the motor stator current, so that a clearer and more recognizable spectrum kurtosis value is obtained, and the judgment capability of current impact and periodic characteristics is enhanced.

The invention provides a frequency voltage support control method and system of an energy storage power station facing a weak power grid, and is applied to the technical field of energy storage control. The method comprises the steps of determining current positive and negative sequence active power and positive and negative sequence reactive power of an energy storage power station and a deviation value of current positive and negative sequence voltage amplitudes and a deviation value of current positive and negative sequence frequencies of the energy storage power station based on three-phase voltage and three-phase current of a common connection point alternating current side of a weak power grid; with safe operation of the energy storage power station as a constraint condition, droop control is carried out based on current positive and negative sequence active power and positive and negative sequence reactive power of the energy storage power station and a deviation value of current positive and negative sequence voltage amplitudes and a deviation value of positive and negative sequence frequencies of the energy storage power station; and controlling active power and reactive power output by the energy storage power station based on the output of the droop control so as to support the frequency and voltage of the main power grid during the power system fault through the energy storage power station. According to the invention, the problem of poor safety and stability of the operation of the weak power grid with the coexistence of frequency and voltage transient disturbance is solved.

The invention relates to the technical field of fault diagnosis, in particular to a pole-mounted circuit breaker fault diagnosis method based on multi-information fusion, and the method comprises the steps: firstly obtaining electric quantity modal data such as three-phase current and coil current and mechanical quantity modal data such as mechanism vibration and voiceprint, and constructing a time-frequency domain alignment feature tensor; then, through a graph space-time attention fusion model, deeply mining physical structure association and time sequence evolution laws among heterogeneous data, and generating a dynamic space-time feature matrix; then, respectively constructing a mechanical evidence body for representing the state of the transmission chain of the operating mechanism and an electrical evidence body for representing the working condition of the vacuum arc-extinguishing chamber by adopting a feature level-decision level mixed framework; an improved D-S evidence theory is applied for fusion, when high-conflict evidences are detected, a self-adaptive arbitration mechanism is automatically triggered, conflict weights are dynamically attenuated or distributed to uncertain items, misjudgment is effectively avoided, and high-robustness collaborative diagnosis of the electromechanical state is achieved.

The invention provides a three-phase current sampling circuit calibration method and system, and belongs to the technical field of permanent magnet synchronous motor three-phase current sampling calibration, and the method comprises the following steps: sequentially giving UVW three-phase current through a motor controller; respectively acquiring three-phase current data through a current sampling circuit in the motor controller and an external current sensor; performing linear fitting on the acquired three-phase current data to obtain a current sampling compensation coefficient of the UVW three-phase current sampling circuit; and multiplying the current sampling compensation coefficient by an initial sampling coefficient of the current sampling circuit, and calculating to obtain an actual sampling coefficient. The current sampling compensation coefficient can more accurately reflect the performance of the current sampling circuit under the actual working condition, so that errors and deviation are reduced, and the sampling precision of the current sampling circuit under the large current is improved.

The invention relates to the technical field of cable short-circuit fault detection, in particular to a power distribution network cable short-circuit fault detection method combined with a power supply network topological relation, and the method comprises the steps: collecting the three-phase current and three-phase voltage of each node at each moment in a power distribution network, and the impedance of each node; determining the current abrupt change rate of each node at each moment; obtaining primary fault features of each node at each moment; obtaining an attenuation coefficient of each node at each moment; determining each fault isolation area in the power distribution network according to the connection state of a circuit breaker in the power distribution network; determining the propagation attenuation weight of each node at each moment; and performing weighting processing on the primary fault features through the reciprocal of the propagation attenuation weight, and detecting the short-circuit fault of the power distribution network cable by using a hybrid classifier by using the weighted primary fault features of all nodes at each moment and combining the node adjacency matrix of the power distribution network and the three-phase current and the three-phase voltage of all the nodes. According to the invention, the accuracy of cable short-circuit fault detection is improved.

The invention relates to the field of fault detection, and discloses a fault online diagnosis method for a low-speed large-torque motor control system, and the method comprises the steps: collecting the multi-dimensional parameters of the three-phase current of a motor, the voltage of a DC bus, the position of a motor rotor, the speed of the motor rotor, and the temperature of a radiator based on a sensor group; carrying out data preprocessing on the collected multi-dimensional parameters to remove noise interference; extracting fault features related to current, voltage, rotor motion and temperature from the preprocessed data; a dynamic threshold value is constructed based on fault features, non-fault parameter fluctuation and fault abnormity are distinguished through multi-feature correlation analysis, and online fault diagnosis is achieved; and finally, outputting a diagnosis result containing the fault type and the fault early warning information. Through multi-dimensional parameter acquisition and dynamic correlation diagnosis, the comprehensiveness and accuracy of fault diagnosis are improved, the false alarm rate is effectively reduced, and the method can adapt to the complex working conditions of load fluctuation and rotating speed switching of the low-speed large-torque motor.

The invention belongs to the technical field of power system power distribution network relay protection, and provides an active fault property discrimination method based on injection disturbance current response characteristics, which comprises the following steps: step 1, when an inter-phase fault occurs in a system, three-phase tripping of a fault line outlet circuit breaker occurs, and according to three-phase current and voltage change conditions before and after the fault, determining whether the fault occurs or not; determining two phases with increased line current and reduced voltage as fault phases; 2, delaying for 200ms after the circuit breaker trips, and controlling the action of a split-phase switch; according to the method, disturbance current signals are injected through an external power supply, the disturbance signals have obvious difference in response characteristics during permanent faults and instantaneous faults, the reliability and superiority of the method under different working conditions are verified through simulation, the method makes up for the defects of an active injection type method during fault property recognition processing, and the method has the advantages of high reliability and high reliability. The method is not influenced by injection time and fault duration, fault property discrimination can be realized only through one-time injection, and the method is simple in operation, small in calculation amount and high in reliability.

The invention discloses a four-wire cascade STATCOM optimized voltage support control method considering active power constraint, which comprises the following steps of: 1, calculating positive and negative zero sequence voltage amplitudes, an initial phase angle and a voltage unbalance degree of a PCC point fault in a three-phase four-wire cascade multi-level energy storage system, carrying out positive and negative zero sequence separation on three-phase current output by the system, and calculating a positive and negative zero sequence voltage amplitude value of the PCC point fault in the three-phase four-wire cascade multi-level energy storage system; obtaining a positive and negative zero sequence voltage amplitude expression; step 2, deriving according to voltage support under active power constraint and current amplitude limiting to obtain the amplitude and phase of the optimal reactive component current injected into the power grid; step 3, obtaining an active component of the reference current needing to be injected through DC capacitor voltage closed-loop control; a switching tube signal of an inverter is generated through a current control loop and a PS-SPWM modulation technology, and the voltage support control method is implemented. After the voltage supporting method provided by the invention is applied, the effect of reducing the degree of unbalance of the PCC point is obvious, and meanwhile, the power balance of the cascaded STATCOM is realized.

The invention relates to the technical field of servo control, in particular to a high-precision current closed-loop control system and method for a servo driver, and the method comprises the steps: collecting three-phase current, rotor position, winding temperature and bus voltage, and constructing a state data set; constructing a parameter identification model fusing physical prior and an attention mechanism, deducing inductance and flux linkage parameters influenced by temperature, saturation and cross coupling, and correcting a motor model in real time; the correction parameters are injected into an FOC decoupling and feedforward link, and a self-adaptive PI regulator is linked to set the gain of a current loop on line; calculating a d-q axis voltage command according to the update model to respectively control excitation and torque components; an extended state observer is introduced to estimate load abrupt change and parameter disturbance, feed-forward compensation is carried out, and three-phase PWM is generated through anti-Parker and SVPWM; and an inverter nonlinear compensation model of a dead zone and switch delay is constructed, PWM is pre-distorted and output to a power device, and robust and low-ripple current closed-loop control of the servo motor is realized.

The invention belongs to the technical field of power electronics of power supply or power distribution, and provides a control method of a three-phase four-wire inverter, a controller and an inversion control system. A first control component is generated by using a phase angle, an inversion side three-phase current sampling value and a proportional integral compensator; a second control component and a third control component are generated by using a power grid voltage angular frequency, a neutral line current sampling value, a repetitive controller and a proportional resonance controller, the three control components are combined to control an inverter power switch tube, a proportional integral compensator is still adopted, the algorithm is simple, parameters are easy to design, and the reliability is high. And meanwhile, a repetitive-proportional resonance (RC-PR) composite controller is utilized to realize suppression of neutral line fundamental wave and harmonic current, and the method has faster dynamic response to load abrupt change, so that optimization of dynamic performance and steady-state performance is realized.

The invention discloses a network construction type energy storage transient performance improving method and system, and the method comprises the steps: dividing a maximum current threshold value of an energy storage current converter in a transient state into a current under a dq coordinate system, calculating the total impedance required by current limiting through combining the component of the A-phase current output by the energy storage current converter on a d axis and the voltage difference between the two ends, setting the virtual impedance, and carrying out the current limiting through the virtual impedance. Virtual impedance is introduced into a current control link to realize over-current limitation; and the current control link outputs voltage, and the output voltage acts on the VSG power control link to realize power angle control. The system comprises a current control module and a power control module. According to the invention, through adaptive adjustment of the virtual impedance and correction of the active power instruction value, the overcurrent is effectively suppressed in the low voltage ride through process, and the power angle of the system is maintained to be stable, so that the transient performance of the network-forming type energy storage system is improved.