2942 results about "Single phase" patented technology

The invention relates to the technical field of single-phase asynchronous motors, and discloses an electronic soft start control method for a single-phase asynchronous motor, which accurately controls the start process of the motor by combining an MCU (Microprogrammed Control Unit) with an electricity metering chip and a silicon controlled rectifier technology. After the system is powered on, the MCU control unit firstly carries out initialization and reads initial circuit parameters collected by the electricity metering chip, and whether starting conditions are met or not is judged based on the parameters. Once the starting condition is confirmed to be met, the MCU sequentially triggers the auxiliary silicon controlled rectifiers to switch on the starting winding and then triggers the main silicon controlled rectifiers to switch on the main winding, so that the motor enters a running state. As the motor reaches a stable operation state, the MCU control unit closes the auxiliary silicon controlled rectifier to reduce unnecessary energy consumption, and adaptively adjusts the conduction time of the starting winding according to the actual load condition, thereby ensuring that the whole starting process is stable and efficient.

The invention provides a field data verification device based on a money-free clamp buckle type single-phase electric energy meter, and the device comprises a host which is used for starting a measurement process through the contact of a probe with a signal contact of the electric energy meter, receiving current data transmitted by a wireless clamp-shaped current transformer, and carrying out the filtering, calibration and error analysis of the measurement data; and the wireless split core type current transformer is used for being clamped on a current loop of the measured electric energy meter, starting to measure current data and sending the current data to the host in a wireless mode. According to the invention, a wireless communication technology, a field data processing algorithm and a verification function are integrated, and field real-time data acquisition, processing, analysis and verification can be realized, so that the efficiency and accuracy of verification work are improved.

The invention belongs to the technical field of flowmeter verification, and discloses a two-phase flow analysis system and method based on a differential pressure flowmeter and an electromagnetic flowmeter. The method comprises the steps that a differential pressure flow meter and an electromagnetic flow meter are arranged on adjacent sections of a pipeline, the electromagnetic flow meter collects voltage signals and analyzes the voltage signals to obtain liquid phase volume flow, and liquid phase mass flow is obtained by combining temperature correction; the differential pressure flowmeter calculates the gas density by using an ideal gas law according to the temperature and the pressure; inputting multi-sensor time sequence data into the weight optimization model, and optimizing the volume gas content and the total mass flow rate; baseline parameters are calibrated during full-pipe single-phase flow to obtain zero drift, and real-time temperature and pressure dynamic correction are combined, so that the metering precision and the working condition adaptability are improved; the problem of verification deviation of a traditional flowmeter is solved, high precision and high reliability of complex gas-liquid two-phase flow metering are achieved, and efficient and reliable technical support is provided for two-phase flow precise metering and process control in the fields of chemical engineering, energy and the like.

The invention relates to the technical field of power electronic equipment testing, and discloses a special intelligent testing device and method for a power UPS, and the device comprises a multi-source power supply system which comprises a three-phase program-controlled variable-frequency power supply, a single-phase program-controlled variable-frequency power supply and a DC program-controlled power supply, the output voltage of the three-phase program-controlled variable-frequency power supply is 0-480V and is adjustable, and the output voltage of the single-phase program-controlled variable-frequency power supply is 0-480V; the output voltage of the single-phase programmable variable-frequency power supply is 0-280V and the frequency of the single-phase programmable variable-frequency power supply is 45-64Hz and adjustable; the output voltage of the direct-current programmable power supply is 50-1000V and adjustable; an electronic load system; a signal acquisition system; an embedded control system; and an upper computer software system. A three-phase program-controlled variable-frequency power supply, a single-phase program-controlled variable-frequency power supply and a direct-current program-controlled power supply are integrated to form a multi-source power supply system, a resistive and rectifying dual-mode electronic load is combined, millisecond-level synchronous switching of a voltage level and a load state is realized through an embedded control system, a closed-loop test capability of multi-dimensional performance of the power UPS is formed, and the test efficiency is improved.

The invention relates to the technical field of charging management, and discloses an intelligent charging management method, device and equipment for an electric scooter and a storage medium, and the method comprises the steps: carrying out the parameter collection and initialization setting of a single-phase bidirectional converter and a permanent magnet synchronous motor in the electric scooter, obtaining system basic parameters and communication data, and obtaining a network authentication identifier and a charging station operation parameter. And dynamic planning of a charging strategy is executed according to the parameters to generate a segmented charging control curve. And the data are input into the self-adaptive prediction controller to realize real-time adjustment in the charging process, and charging state data and power compensation parameters are obtained. And adopting a double-neural network model structure to obtain a battery safety feature matrix and a fault probability vector. And constructing a three-dimensional charging state space model to carry out optimization calculation on the power compensation parameters, inputting a deep reinforcement learning network to carry out iterative optimization, and generating charging control parameters of the next period, thereby improving the charging efficiency and the electric energy quality of the electric scooter.

The invention provides an XLPE cable aging-based mixed operation system impedance mismatch and imbalance characteristic analysis method, equipment and a medium, and belongs to the technical field of cable aging analysis. Equivalence simplification is performed on a power grid in a simulation system, switching stations and transformer substations are reserved, and a cable structure model is constructed; cable structure parameters are obtained, three-phase unbalanced current-carrying simulation conditions are set, operation parameters are obtained, a cable finite element thermal field analysis model is constructed, cable thermal field analysis data are input, and cable burying depth and surrounding parameters are set; comparing and analyzing the temperature distribution difference, acquiring temperature data of the inner and outer surfaces of the insulating layer, and calculating an average temperature difference value of the insulating layer under the two working conditions; based on the average temperature difference value, the influence degree of the single-phase power-on working condition on the cable insulation life compared with the symmetrical operation working condition is quantified. And according to an evaluation result, a more reasonable cable maintenance plan and replacement period are formulated, faults caused by insulation aging are prevented in advance, and safe and reliable operation of a power system is guaranteed.

The invention relates to the technical field of single-phase asynchronous motors, and discloses a single-phase asynchronous motor starting control circuit based on an MCU and double silicon controlled rectifiers, which comprises an MCU control unit, a main silicon controlled rectifier, an auxiliary silicon controlled rectifier, an electricity metering chip and a protection circuit. Particularly, in a starting stage, the MCU control unit firstly sends a trigger signal to the auxiliary silicon controlled rectifier to enable the auxiliary silicon controlled rectifier to be in a conducting state, and the auxiliary silicon controlled rectifier is controllably connected with the starting winding to provide extra starting torque for the single-phase asynchronous motor; and after a starting condition is met, the MCU control unit sends a trigger signal to the main silicon controlled rectifier to enable the main silicon controlled rectifier to be in a conducting state, and the main silicon controlled rectifier is connected with the live wire to enable the single-phase asynchronous motor to enter a normal operation state. Thus, the starting winding is only electrified when necessary, energy loss caused by continuous heating of the PTC is avoided, and the overall energy efficiency of the system is improved.

The invention discloses a zero-sequence pilot-frequency excitation method for a double-circuit line in an incomplete power failure environment, which comprises the following steps of: applying zero-sequence pilot-frequency signal excitation on a power failure line by using a pilot-frequency power supply as an excitation signal source of a zero-sequence network of the double-circuit line, different-frequency induced current and voltage are measured at secondary sides of a current transformer and a voltage transformer at two sides of the operation line, and different-frequency zero-sequence voltage and different-frequency zero-sequence current in the double-circuit line zero-sequence network are obtained; simultaneously solving a zero-sequence network equation, and calculating mutual impedance between double circuits; performing frequency conversion to obtain the power frequency mutual impedance of the line; and finally, carrying out simulation verification by constructing a non-full-stop double-circuit line zero-sequence mutual inductance impedance measurement system. According to the method, the multi-path coupling caused by the existing power frequency interference method and the accuracy problem caused by the signal measurement error of the zero sequence increment method are solved, the test calculation can be accurately completed under the complex interference working condition, and the safety risk caused by the single-phase reclosing operation is avoided.

The invention discloses a single-phase charge-control intelligent electric energy meter and an intelligent metering system thereof, relates to the technical field of electric variable measurement, and aims to solve the technical problem of inaccurate metering of the existing intelligent electric energy meter, and the single-phase charge-control intelligent electric energy meter comprises a working electric quantity calculation module which is connected to a power grid and is used for counting the electric quantity when the electric energy meter works and storing the electric quantity in a memory; the non-working electric quantity calculation module is used for calculating the electric quantity when the electric meter does not work; the working electric quantity calculation module further comprises a first processing unit which is used for calculating the working electric quantity consumed when the electric meter works according to the working duration of the electric meter; the first calculation unit is used for receiving the working electric quantity from the first processing unit, calculating corrected electric quantity according to the working electric quantity and historical electric quantity data stored in the memory, and transmitting the corrected electric quantity to the correction unit; and the correction unit is used for receiving the correction electric quantity transmitted by the first calculation unit and correcting the working electric quantity. The method has the advantage of improving the electricity metering accuracy of the electricity meter.

The invention discloses a high-voltage cable terminal parallel connection lightning arrester total current online monitoring method and system, and relates to the technical field of power grid equipment, and the method comprises the steps: obtaining the cable coupling coefficient of each cable terminal to a current lightning arrester under the single-phase effect at a test stage, and obtaining the cable coupling coefficient of each cable terminal to the current lightning arrester; obtaining an inter-phase coupling coefficient between the current lightning arrester and the remaining lightning arresters under the single-phase action; in actual work, the leakage current detection module is adopted to obtain the leakage current induction value of the current lightning arrester on line; the power frequency calibration coefficient is adopted to calibrate the leakage current induction value, and a leakage current calibration value of the current lightning arrester is obtained; based on the leakage current calibration value, the cable coupling coefficient and the interphase coupling coefficient, obtaining a current leakage current actual value of the lightning arrester; in the scheme of the invention, coupling interference caused by spatial distribution is fully considered, correction is carried out based on the cable coupling coefficient and the interphase coupling coefficient to eliminate interference caused by spatial distribution parameters, and the current leakage amount of the lightning arrester can be accurately monitored.

Disclosed are a single-phase-to-ground protection method and system for an active power distribution network. The method includes: acquiring current and voltage data of a line in real time by means of a power distribution terminal, and calculating active power of the line; recording and storing the active power of the line to form an active power curve; performing data statistics according to the active power curve; calculating a direction compensation coefficient and a zero-sequence current compensation coefficient on the basis of statistical data; and detecting whether a single-phase-to-ground fault occurs to the line, where when the single-phase-to-ground fault occurs to the line, a transient-state zero-sequence direction and a steady-state zero-sequence direction are compensated, or a zero-sequence current is compensated, it is determined that the single-phase-to-ground fault occurs to the line when compensation results satisfy action conditions, and tripping is performed or an alarm is given.

The invention relates to a single-phase load identification intelligent ammeter, which relates to the technical field of ammeters, and comprises an ammeter body, a terminal cover and a fixing piece, the ammeter body is provided with a wiring area, a display area and a drainage channel penetrating through two sides of the ammeter body, and the terminal cover is hinged on the ammeter body and covers the wiring area and the drainage channel. The fixing member is used for detachably fixing the terminal cover on the ammeter body. The plugging part is arranged on the terminal cover, the plugging groove is arranged in the wiring area, the fixing piece is taken down from the plugging part to form an air guide flow channel between the plugging part and the wiring area, and the air guide flow channel is communicated with the drainage channel. Air is supplied to the plugging part through external air supply equipment, dust removal air can be blown into the wiring area along the air guide flow channel and is discharged through the drainage channel, dust in the wiring area can be cleaned under the condition that the terminal cover is not opened, the dust removal efficiency is improved, and the maintenance risk is reduced.

The utility model discloses a single-phase one-meter-position electric energy metering box, which relates to the technical field of electric power metering boxes and comprises a box body, the inner wall of the box body is fixedly connected with a fixed plate and a sliding frame, the sliding frame is located at the top of the fixed plate, and two sides of the fixed plate are symmetrically and fixedly connected with supporting plates. And guide rods are symmetrically and slidably connected to the interior of the supporting plate, and one end of each guide rod is fixedly connected with a clamping frame. According to the single-phase one-meter-position electric energy metering box, through the symmetrical clamping frames, when an electric energy meter is fixed, the action of holding the electric energy meter by lifting a hand is not required to be kept all the time, the clamping frames on the two sides can automatically center and fix the electric energy meter, and meanwhile, the fixing claws on the top have the effect of limiting the positions of the clamping frames; and when the box body shakes, the clamping frame does not lose the fixing effect on the electric energy meter, so that the fixing effect is enhanced.

The invention provides a distributed AC / DC uninterruptible power supply system, which comprises a PLC main control module and a power supply monitoring controller, the AC-DC rectifier module provides a main power supply for the system; the alternating-current and direct-current inverter is used for current conversion and providing an uninterrupted alternating-current power supply; the static switch performs power supply switching between the battery pack and the commercial power; the direct-current starting module activates a direct-current starting function and realizes alternating-current and direct-current uninterruptible power supply; the four-port isolation module realizes current single-phase flow of the battery pack and the intelligent charger; the battery management module is used for uninterruptedly supplying power; the intelligent heat dissipation module is used for automatically dissipating heat in a high-power operation state; and the human-computer interface and the configuration software are used for displaying the operation data and the operation state in real time and carrying out remote management. The battery pack is in an off-line mode; a high-speed switch is adopted for switching, a complete battery management system is adopted, the service life of a battery pack is prolonged, reliable alternating-current and direct-current uninterruptible power supply is achieved, faults are reduced, and intelligent power supply management is achieved.

The invention provides a railway flexible traction system based on multi-source fusion. The system is composed of a central control unit, a V / v traction transformer unit and a multi-port flexible interconnection unit. The V / v traction transformer unit comprises a first power supply arm, a second power supply arm and a third power supply arm, the input ends of the V / v traction transformer unit are connected with a public power grid, the first and second power supply arms are connected to the multi-port flexible interconnection unit, and the third power supply arm provides passive support for a traction network. The multi-port flexible interconnection unit comprises a two-phase rectification module, a photovoltaic power generation module, an energy storage module and a single-phase inversion module which are commonly connected to a DC bus. The central control unit adjusts the output power of the multi-port flexible interconnection system and the control strategy of the single-phase inversion module in real time so as to realize flexible consumption of new energy and improvement of power supply stability. The system has the advantages of compatibility, cost effectiveness, new energy access and consumption, power supply reliability improvement, electric energy quality optimization, high adaptability and the like, and is suitable for upgrading and reconstruction of newly-built railway lines and existing railway lines.

The invention belongs to the technical field of DC power grid short-circuit current calculation, and particularly relates to a short-circuit current calculation method for a metal backflow four-terminal bipolar DC power grid, and the method comprises the steps: S1, building an MMC equivalent model; s2, constructing and processing an equivalent circuit of a Bergeron lossy transmission line of the DC line to obtain a Bergeron two-port equivalent model of a single-phase transmission line and a Bergeron equivalent model of a three-phase transmission line; s3, establishing an equivalent model of the metal backflow four-terminal bipolar direct current power grid; s4, establishing an accompanying circuit model of the metal backflow four-terminal bipolar direct current power grid; s5, constructing a conductance matrix G, and forming a node voltage equation; and S6, according to the fault type, modifying a node admittance matrix G in the node voltage equation into an equivalent conductance matrix G ', and then solving the modified node voltage equation to obtain the branch current and the node voltage after the fault. According to the method, the problem that the short-circuit current calculation method of the metal backflow four-terminal bipolar direct-current power grid is insufficient in accuracy can be solved.

The invention discloses a multi-phase-multi-phase direct-type AC-AC converter based on an MMC and a control method of the multi-phase-multi-phase direct-type AC-AC converter. The AC-AC converter provided by the invention comprises a modular multi-level converter and N single-phase three-winding transformers, the modularized multi-level converter comprises X phase units, the input side is provided with m ports and connected with a first alternating current system, and the output side is provided with N ports and connected with a second alternating current system. Each single-phase three-winding transformer comprises a first winding, a second winding and a third winding, the first windings of the N single-phase three-winding transformers are respectively connected with N phases of a second alternating current system, and the second windings are connected with N output side ports of an upper bridge arm of the modular multilevel converter; and the third winding is connected with N output side ports of the lower bridge arm of the modular multilevel converter. The AC-AC converter is based on the principle of synthesis of differential-mode and common-mode voltage components of MMC bridge arms, and is combined with a three-winding transformer with an anti-dotted terminal, so that the number of sub-modules of the M3C topology can be further reduced, and the AC-AC converter has good expansibility and is suitable for application scenes with various special requirements.

A wireless power transfer (WPT) device includes a polyphase coil network comprising a plurality of phases for transfer of high-frequency AC power, each one of the plurality of phases comprising a phase coil, wherein the polyphase coil network is configured to operate in a polyphase configuration to enable transfer of polyphase high-frequency AC power with a mating WPT device operating in a polyphase mode; and operate in a single phase interoperability configuration to enable transfer of single phase high-frequency AC power with a mating WPT device operating in a single phase mode.

The invention belongs to the technical field of electric energy meters, and particularly relates to a single-phase electric energy meter with a magnetic ring compensation structure. The device comprises a gap magnetic ring modeling unit, a compensation coil current setting unit, a driving voltage real-time generation unit and a pulse output unit, the notched magnetic ring modeling unit is used for calculating corresponding uncompensated magnetic flux based on the magnetic conductivity after temperature correction; the compensation coil current setting unit is used for forming a compensation coil current setting value; the driving voltage real-time generation unit is used for injecting bidirectional current matched with a compensation coil current set value into the compensation coil; the pulse output unit is used for triggering metering pulse output; the method has the beneficial effects of high precision, high stability, low power consumption and high robustness.

The invention discloses a transformer area low-voltage cause analysis method and device and a medium. The method comprises the following steps: acquiring acquisition information of a transformer area in real time; determining a low-voltage event of the transformer area according to the acquired information; the causes of the low-voltage event are analyzed through the collected information to obtain the low-voltage cause, and the low-voltage cause comprises single-phase disconnection, single-phase grounding, three-phase imbalance, distribution transformer outlet metering device fault, low power factor, unreasonable transformer gear and low-voltage abnormity; and performing intelligent decision according to the low-voltage cause to obtain conclusion information. By acquiring the acquisition information of the existing power distribution automation system and determining the low-voltage event and the specific low-voltage cause according to the acquisition information, low-voltage monitoring and cause analysis can be realized without additional equipment, the cause of the low voltage in the transformer area can be analyzed and judged in real time, the analysis cost is low, the applicability is wide, and the method is suitable for popularization and application. The method can be widely applied to the technical field of power distribution networks.

Example embodiments of systems, devices, and methods are provided for energy systems having multiple modules arranged in cascaded fashion for generating and storing power. Each module can include an energy source and switch circuitry that selectively couples the energy source to other modules in the system for generating power or for receiving and storing power from a charge source. The energy systems can be arranged in single phase or multiphase topologies with multiple serial or interconnected arrays. Thermal management systems, switching assemblies, physical layouts of a module, and EV models based on a universal platform are also described.

Disclosed is a single phase liquid immersion cooling system with a forced cooling circuit for cooling heat-generating electronic devices, such as servers. The cooling system comprises an immersion cooling unit, a heat exchanger, and a dielectric fluid circulating unit. The immersion cooling unit includes a tank within which dielectric fluid and heat-generating electronic devices are maintained. The heat-generating electronic devices are provided with a radiator and submerged in the body of dielectric fluid. The dielectric fluid circulating unit includes a fluid outlet pipe interconnecting the heat exchanger with the tank, a motor pump disposed on the fluid outlet pipe, a manifold, a first fluid inlet pipe interconnecting the manifold with the heat exchanger, and a second fluid inlet pipe interconnecting the manifold with the radiator.

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 present disclosure relates to circuits for connecting components of a hydrogen plant to a power grid to power the components in an efficient manner. In one implementation, power-side alternate current (AC) to direct current (DC) converters may be connected to a source power grid without the need for an isolation transformer by providing separate buses between the power-side AC-DC converters and load-side DC-DC converters instead of a shared DC bus between the converters. Other implementations for connecting components of a hydrogen plant to a power grid may include an adjustable transformer, such as a tappable transformer or an autotransformer, to connect any number of auxiliary loads of the plant to the power grid. The adjustable transformer may provide for various types of auxiliary load devices to connect to the power provided by the transformer at the same time, including both three-phase devices and one-phase devices.

The invention provides a single-phase four-quadrant rectifier IGBT open-circuit fault diagnosis method under multiple working conditions, and relates to the technical field of IGBT fault diagnosis. Historical data of alternating current side voltage, alternating current side current and direct current side voltage of the single-phase four-quadrant rectifier are obtained, and a total harmonic distortion rate threshold value, a direct current side voltage threshold value and an alternating current side current first threshold value are obtained. And constructing and training an IGBT open-circuit fault positioning identification model. Detecting the total harmonic distortion rate of the alternating-current side current of the single-phase four-quadrant rectifier in real time, if the total harmonic distortion rate exceeds a threshold value, entering fault positioning, collecting and calculating the average value of the direct-current side voltage and the alternating-current side current in the period, and judging the fault of the single-phase four-quadrant rectifier under the specific working condition according to the comparison of the average value and the threshold value. Or using an IGBT open-circuit fault positioning identification model to diagnose the fault; if the threshold value is not exceeded, the next period is continuously monitored. According to the invention, the IGBT fault diagnosis efficiency and accuracy of the single-phase four-quadrant rectifier are improved.

The invention relates to the technical field of electric energy meter on-site calibrators, in particular to a one-way electric energy meter on-site calibrator wiring device and a testing method.The one-way electric energy meter on-site calibrator wiring device comprises an insulating resin body, the insulating resin body comprises a base and two side columns wrapping an electric energy meter from the two side faces, and the base and the side columns are integrally formed through pouring of insulating resin; a plurality of limiting holes corresponding to binding posts of the electric energy meter are formed in one side of the insulating resin body, spring probes with two ends extending to the outside of the limiting holes are arranged in the limiting holes, and one end of each spring probe is connected with a plug; the spring probe comprises a longitudinal rod with one end extending into the limiting hole, the top of the longitudinal rod is connected with a longitudinal pipe, and the top of the longitudinal pipe is provided with a voltage contact with one end movably extending into the longitudinal pipe. The problem that an existing electric energy meter wiring device is difficult to quickly and safely complete wiring of a single-phase electric energy meter on-site calibrator and meet the requirement of accessing a load when the electric energy meter is needed is solved.

The invention discloses an electric meter data storage method of a single-phase cost-control electric energy meter, and relates to the technical field of intelligent electric meter data processing, and the storage method comprises the following specific steps: S100, data acquisition and characteristic pro-analysis: acquiring voltage, current and power data of the single-phase cost-control electric energy meter through a voltage sensor and a current sensor, by integrating the voltage sensor and the current sensor, real-time and accurate acquisition of key power utilization data of voltage, current and power of the single-phase charge-control electric energy meter is realized, and by introducing a dynamic time window setting mechanism, the length of a time window is automatically adjusted according to the fluctuation amplitude of the data, so that the accuracy of power utilization is improved. It is ensured that a window is shortened to capture transient changes when data fluctuates violently, the window is prolonged to reduce redundant collection when the data is stable, the flexibility and accuracy of data collection are improved through intelligent adjustment, subsequent data processing can be conducted based on richer and more detailed feature information, and the data collection efficiency is improved. And the intelligent level of the whole data storage system is obviously improved.

The invention provides a power fluctuation suppression method and system based on two-phase virtual phase current regulation and control. The method comprises the steps that S1, a grid-connected current model and a direct-current bus power fluctuation model are constructed; a two-phase virtual phase current regulation and control technology is introduced into the grid-connected current model; the DC bus power fluctuation model corresponds to the grid-connected current model; s2, optimizing a direct current bus power fluctuation model; and S3, solving the optimized direct current bus power fluctuation model to complete the complete suppression of the power fluctuation. On the basis of the single-phase VPCR technology, one of the phases without voltage drop in the three phases is additionally selected as an auxiliary compensation phase, optimization calculation of a two-phase virtual phase current gain coefficient is carried out through a particle swarm optimization algorithm, it is proved from the theoretical level that the two-phase VPCR technology can achieve minimization and zero of direct-current side power fluctuation, and the method is suitable for large-scale popularization and application. The traditional engineering requirements are met, and the design defect of the gain coefficient of the single-phase VPCR technology is improved.

The invention belongs to the field of stability analysis of a grid-connected system of a grid-building converter, and particularly relates to a grid-building converter grid-connected resonance risk analysis method considering virtual impedance, which comprises the following steps: S1, establishing a three-phase time domain differential equation and simplifying the equation into a single-phase equivalent time domain model; converting into a harmonic state space model of the main circuit; s2, constructing a harmonic state space model of a control system comprising an active power control loop and a reactive power control loop; s3, introducing a virtual impedance control link, and correcting the voltage amplitude reference phasor output by the reactive power control loop; deriving an expression of a modulation signal disturbance phasor; s4, obtaining a complete frequency domain admittance model YGSC of the network construction converter considering the influence of the virtual impedance; an open loop gain TGFM of the grid converter grid-connected system is constructed; and S5, drawing a Nyquist curve based on TGFM, and carrying out resonance risk determination. According to the method, the interaction dynamic characteristics of the network building converter and the power grid under the influence of the virtual impedance can be accurately represented, and the resonance risk of the grid-connected system is evaluated.

The invention discloses a power supply circuit and electrical equipment. The power supply circuit comprises a three-phase power supply and three rectification and inversion modules, wherein each rectification and inversion module comprises a first input end, a second input end and an output end; the first input ends of the three rectification inversion modules are respectively connected to three phase lines in a three-phase power supply in a one-to-one correspondence manner; second input ends of the three rectification inversion modules are connected to a neutral line in the three-phase power supply; the output ends of the three rectification inversion modules are respectively connected to three loads in a one-to-one correspondence manner; and the rectifying and inverting module is used for sequentially rectifying and inverting the input voltage and then supplying power to corresponding loads. According to the invention, the three-phase power supply is divided into three independent single-phase power supply paths for three loads, single-phase rectification is carried out on each phase independently, the voltage level is reduced, a low-voltage-level device can be selected, and the cost is reduced; the three-phase load is balanced, the harmonic dispersion is realized, and the harmonic pollution is reduced; fault area isolation is realized, and maintenance difficulty and maintenance cost are reduced.