327 results about "Single-phase electric power" patented technology

The invention relates to the technical field of low-voltage single-phase energy storage, and discloses a low-voltage line single-phase distributed energy storage system and a control method thereof.The energy storage system comprises a control system and a plurality of distributed independent energy storage systems, and each independent energy storage system comprises a controller, a converter and an energy storage unit; the controllers are respectively connected with the converters and the energy storage units, the energy storage units are connected with the single-phase low-voltage lines through the converters, the controllers are in communication connection with the control system, and the control system controls the converters to charge and discharge electric energy according to the power grid environment where the energy storage units are located. The safety detection of each independent energy storage system is realized through a single battery self-checking device and a system self-checking component of each independent energy storage system, the charging and discharging states of each battery are safely controlled, and each independent energy storage system realizes precise voltage support and flexible energy buffering through single-phase independent regulation and control; dynamic optimization of single-phase electric energy quality is realized by adopting a power control strategy, and the technical blank of traditional centralized energy storage in the field of single-phase electric energy regulation and control is filled.

The invention relates to the technical field of air door motor control, and discloses an air door motor control method and system based on current detection, and the method comprises the steps: carrying out the single-phase current signal collection of an air door motor system, and obtaining a current change signal in the opening and closing process of an air door; carrying out FFT (Fast Fourier Transform) and wavelet decomposition processing on the current change signal to obtain a current characteristic spectrum component and a time domain characteristic; processing the current characteristic frequency spectrum component and the time domain characteristic to obtain an air door load current characteristic; iterative learning control is executed, and air door rotating speed control parameters are generated; the PWM duty ratio is calculated, and air door motor driving pulses are generated; according to the air door motor control method, a complete air door motor control protection mechanism is established, abnormal conditions such as stalling can be detected and coped with in time, the safety of an air door motor system is improved, and the service life of the air door motor system is prolonged.

The invention relates to an open-circuit fault detection method and device, a domain controller, a system and a vehicle, and relates to the technical field of open-circuit fault detection. According to the method, the three-phase current data of the cooling water pump can be firstly obtained, and under the condition that at least one phase of current data in the three-phase current data meets the pre-judged open circuit condition, at least one of the following motor parameters including the three-phase current unbalance degree, rotor data and water pump vibration data is monitored. If it is monitored that any motor parameter in the three-phase current unbalance degree, the rotor data and the water pump vibration data is abnormal, it is determined that the current data meeting the pre-judgment open-circuit condition occurs, and an open-circuit fault occurs to the target phase corresponding to the current data meeting the pre-judgment open-circuit condition. Therefore, under the condition that the suspected open circuit of the corresponding phase is predicted according to the single-phase current, prediction can be performed by fusing at least one motor parameter of the cooling water pump, so that the misjudgment rate of the open-circuit fault of the cooling water pump can be reduced and the open-circuit phase positioning precision can be improved through multi-data cooperative detection.

A first winding is wound around a first middle column of a first magnetic core, and a second winding is wound around a second middle column of a second magnetic core. The third magnetic core is located between the first winding and the second winding, the third magnetic core has a through hole, and both the first middle column and the second middle column extend into the through hole. When a direction of a magnetic field generated by the first winding is the same as a direction of a magnetic field generated the second winding, the first magnetic core and the second magnetic core generate common-mode inductance. When a direction of a magnetic field generated by a third winding is opposite to a direction of a magnetic field generated a fourth winding, the third magnetic core generates differential-mode inductance.

The invention provides an on-site calibration device, method and system applied to a single-phase electric energy metering device, and relates to the technical field of metering device calibration, and the device comprises a main body, a display screen and a clamp meter. A crimping panel is arranged on the lower end surface of the main body; a plurality of crimping needles are arranged on the crimping panel, and the crimping needles are matched with crimping holes formed in the single-phase electric energy metering device to realize crimping; a locking nut is arranged on the main body, the locking nut penetrates through the main body from top to bottom, and the main body is fixed on the single-phase electric energy metering device through the configuration of the locking nut and a threaded hole formed in the single-phase electric energy metering device. According to the invention, the device main body and the single-phase electric energy metering device are buckled together, a worker can leave the field only by completing buckling, and returns to the field to be taken back after the device completes automatic inspection, so that the worker efficiency and multi-point inspection are both considered, and the overall performance of the single-phase electric energy meter within the working range of the single-phase electric energy meter is inspected.

The invention relates to an overvoltage risk assessment method, device and equipment for non-full-phase operation of a new energy access weak power grid system. The method comprises the following steps: acquiring electrical quantity data of the new energy access weak power grid system, and a voltage source, grid-connected equivalent impedance, series equivalent impedance and non-full-phase operation line impedance of a power transmission line of the new energy access weak power grid system with a single-phase fault; calculating n positive sequence current vectors and negative sequence current vectors according to each piece of electrical quantity data; calculating n positive sequence port voltage vectors and negative sequence port voltage vectors according to the fault data, each positive sequence current vector and each negative sequence current vector; according to the positive sequence voltage component rated value, each positive sequence port voltage vector and each negative sequence port voltage vector, actual positive sequence voltage and actual negative sequence voltage are obtained through calculation; and according to the actual positive sequence voltage, the actual negative sequence voltage and the positive sequence voltage component rated value, calculating to obtain a single-phase voltage maximum value, and according to the single-phase voltage maximum value, judging whether the system has an overvoltage risk in a non-full-phase operation state.

The invention belongs to the technical field of power grids, and particularly relates to a hydrogen fuel cell grid-connected inverter fault test and ride-through method. Comprising the following steps: S1, simulating three-phase symmetrical voltage drop, inter-phase voltage drop and single-phase voltage drop of a power grid through a low-voltage fault generation device; s2, collecting the voltage of a power grid through a high-precision voltage sensor, and when the voltage of the power grid drops, judging whether the system needs to carry out low-voltage ride through at the moment according to a distributed energy low-voltage ride through curve; and S3, when the system needs to carry out low-voltage ride-through, a dual-second-order generalized integrator pre-filtering phase-locked loop (DSOGI-PLL) is combined with grid-connected point voltage full-feedback compensation, negative-sequence components generated by symmetric and asymmetric drop of the power grid voltage are eliminated, and current impact suppression and negative-sequence current elimination are realized. The problem of power grid synchronization under the condition of power grid voltage drop is finally solved.

The invention relates to the technical field of electric energy metering error compensation, in particular to an electric energy metering error compensation method, device and system, and the method comprises the steps: collecting a single-phase electric energy signal of a secondary side of a power grid transformer, and uniformly dividing the single-phase electric energy signal into each section of metering signal sequence; calculating high-frequency unsteady-state energy to quantify distortion by extracting first-order and second-order quasi-steady-state components of a metering signal sequence; meanwhile, impact pulses in the dynamic components are recognized, impact characteristics are analyzed through clustering, and the nonlinear impact disturbance degree is comprehensively calculated; the fundamental wave separation strength of each section of metering signal sequence is calculated, the initial step length factor of the LMS filtering algorithm is dynamically adjusted, effective separation of fundamental waves and distortion signals is achieved, and therefore electric energy metering error compensation is completed. The method aims at solving the problem that the metering precision of a traditional fixed step length factor is reduced under the power grid nonlinear load high permeability working condition, and the accuracy and reliability of electric energy metering are ensured.

The invention relates to a multi-structure self-adaptive electric energy meter non-power-cut replacement device and a use method. The multi-structure self-adaptive electric energy meter non-power-cut replacement device comprises a control host connected with a single-phase electric meter; the wire inlet side and the wire outlet side of the single-phase electric meter are respectively connected with switches of the same type or different types, the switch of the wire inlet side is connected with a power supply side socket of the control host through a wire inlet electricity taking module, the switch of the wire outlet side is connected with a user side socket of the control host through a wire outlet electricity taking module, and the control host and the single-phase electric meter form a parallel bypass; the lower part of the single-phase ammeter is provided with a connection terminal area, the connection terminal area is provided with four ammeter buses which are arranged at intervals, and each ammeter bus is locked with the single-phase ammeter through a wire locking screw. The connection terminal area is detachably connected with a short circuit module, the short circuit module is connected with the control host and the locking wire screw, the adjacent ammeter buses are locked or loosened by adjusting the locking wire screw, the single-phase ammeter is seamlessly switched from an original circuit to a parallel bypass, and meanwhile the passing electric quantity is continuously metered.

An electrical conductor monitoring system for single or multi-phase conductors is described. The monitoring system may be configured to monitor the health of a conduction system based on multi-phase sequences and / or current magnitude and angle vectors of multi-phase or single-phase current. In one example, the monitoring system includes an insulation health monitoring system having an input and output measurement devices, the input measurement device disposed at an input end of the electrical distribution system and structured to measure three-phase input currents, the output measurement device disposed at an output end of the electrical distribution system and structured to measure three-phase output currents; and a monitoring device communicatively coupled to the measurement devices and structured to receive the three-phase input and output currents from the measurement devices and determine a state of the insulation system based on the three-phase input and output currents. Other embodiments are described.

The invention belongs to the technical field of power grids, and relates to a voltage and current phase sequence recognition device based on single-phase voltage sampling and others, the phase sequence recognition device comprises a device power supply unit, a voltage sampling unit, three current detection units and a data processing unit, the device power supply unit is connected in parallel with the voltage sampling unit, and the three current detection units are connected in parallel with the data processing unit. The voltage sampling unit carries out voltage sampling on any phase line in the three-phase four-wire system power grid, the three current detection units carry out current sampling on each phase line of the three-phase four-wire system power grid, and the data processing unit reconstructs voltage signals of the other two phases according to voltage sampling models and current sampling signals. And identifying the phase sequence of the voltage and the current of the three-phase four-wire system power grid. According to the invention, the phase sequence identification of the three-phase line voltage and the three-phase current can be carried out only by sampling the single-phase voltage signal and the three-phase current signal, and the method has the characteristics of fast phase sequence identification speed and high efficiency, and also has the characteristics of simple installation, convenient use and plug-and-play.

The application discloses a novel lung lobe-shaped magnetic shielding partial discharge detection device and a detection method. The device comprises an isolation transformer, a bushing, a detection electrode and a partial discharge instrument. A single-phase power supply is connected with a reactor in parallel, and then connected with an input end of the isolation transformer. One end of an output end of the isolation transformer is connected with the bushing, and then connected with the detection electrode. The other end of the output end of the isolation transformer is grounded. A grounding end of a to-be-detected lung lobe-shaped magnetic shielding is grounded, and the grounding end of the to-be-detected lung lobe-shaped magnetic shielding is connected with the partial discharge instrument. The to-be-detected lung lobe-shaped magnetic shielding and the detection electrode are correspondingly arranged to form an equivalent capacitor and are coupled and connected. The application can be used to determine whether there is a defect in the lung lobe-shaped magnetic shielding by performing a partial discharge test on the lung lobe-shaped magnetic shielding before the lung lobe-shaped magnetic shielding is assembled into a transformer. The application has the characteristics of high test efficiency and low applied voltage, and greatly improves the first-time pass rate of the transformer product provided with the lung lobe-shaped magnetic shielding.

The application discloses a kind of electric energy meter replacement period electric quantity loss metering method and system, first determine the electric voltage test loop quantity involved in electric quantity metering of the electric energy meter to be replaced, and configure the pair of current transformer clamp and single-phase electric energy meter for each electric voltage test loop;The pair of current transformer clamp is respectively clamped to the current input line, output line of each electric voltage test loop high voltage phase, and the single-phase electric energy meter is connected to the secondary winding of corresponding current transformer clamp;Then, the secondary winding of high-voltage current transformer connected to the electric energy meter to be replaced is short-circuited, and the power consumption wh1 on the single-phase electric energy meter at this stage is recorded;The electric energy meter to be replaced is removed, and the power consumption wh2 on the single-phase electric energy meter at this stage is recorded;New electric energy meter is connected to joint terminal box, and the power consumption wh3 on the single-phase electric energy meter at this stage is recorded;Finally, the power consumption loss during electric energy meter replacement is calculated according to wh1, wh2 and wh3.The application is more efficient and safer.

The present invention discloses a method and system for predicting single-phase electric energy meter burnout based on electric meter data, which relates to the field of intelligent early warning technology for single-phase electric energy meters. The present invention not only obtains a three-dimensional array by analyzing the historical time series data of the single-phase electric energy meter, but also obtains a three-dimensional array by analyzing the historical time series data of the single-phase electric energy meter. X reshaped , and further extracts a variety of engineering features from a multi-dimensional perspective to obtain a multi-dimensional array X' eng This provides a more comprehensive and robust basis for risk assessment, helping to improve the model's generalization capabilities. Furthermore, the present invention provides a burnout prediction model that combines the advantages of deep learning and machine learning, fully exploiting the inherent patterns in electricity meter data to achieve highly accurate predictions of burnout risks. This invention addresses the limitations and ineffectiveness of existing single-phase electricity meter prediction technologies.

The utility model discloses a damping single-phase electronic electric energy meter box, which comprises an electric energy meter box module, and the electric energy meter box module comprises a box body frame. The convenient disassembly and assembly module comprises a guide groove formed in the center of the front face of the inner wall of the box body frame, a guide block is slidably arranged in the guide groove, the front face of the guide block is sleeved with a mounting plate, sliding grooves are formed in the two opposite sides of the inner wall of the guide groove, and sliding blocks are fixedly arranged on the upper portions of the two sides of the guide block; the sliding rod extends into the sliding groove and abuts against the lower end; the device further comprises a damping module, the damping module comprises movable grooves symmetrically formed in the ends of the two opposite sides of the inner wall of the box body frame, micro hydraulic dampers are arranged at the rear ends of the inner walls of the movable grooves, one ends of the micro hydraulic dampers are sleeved with movable blocks, and movable plates are fixed to one ends of the multiple movable blocks. The electric energy meter can be conveniently disassembled and assembled at a low position, time and labor are saved, simplicity and convenience are achieved, use is convenient, requirements are met, and the use effect is improved.

An electrical converter may include AC terminals, a first and second DC terminal, and converter modules. Each of the converter modules has an AC node. The second DC terminal forms a common node of the converter modules. A connection between the AC nodes of the converter modules and the AC terminals is reconfigurable allowing the electrical converter to operate according to a first mode of operation converting between a first AC signal having a first plurality of phase voltages and the DC signal, in which the converter modules are grouped in first groups, and according to a second mode of operation converting between a second AC signal having a single-phase voltage and the DC signal, in which the converter modules are rearranged in second groups. The electrical converter is configured to operate multiple converter modules assigned to a same group of the first groups and the second groups in parallel.

The invention discloses a fault-tolerant control method for current sensors of a single-inverter double-parallel permanent magnet synchronous motor. Two current sensors and two position encoders need to be configured under an average control framework. However, the current sensor is easy to have various faults and becomes a main weak link of system reliability. In order to solve the problem, the invention discloses a current sensor fault-tolerant control method for a double-parallel motor driving system. According to the method, a virtual invariant manifold technology is fused, a Kreisselmeier regression extension observer is designed, and accurate reconstruction of three-phase current can be realized only by depending on single-phase current information. On the basis, a current sensor fault positioning and fault-tolerant control mechanism is further constructed, it is ensured that the system can still operate continuously and stably when the current sensor breaks down, and the robustness and reliability of the driving system are remarkably improved.

A single-phase electricity meter comprises a shell and an electricity connection structure arranged in the shell, a circuit board is connected to the electricity connection structure, the electricity connection structure comprises a junction box and a plurality of binding posts arranged in the junction box in a press-in mode, diverters are connected to the binding posts, and the diverters are in hard connection with the circuit board; compared with the prior art, the wiring terminal is arranged in the wiring box in the press-in direction, and other structures are not needed to connect the wiring terminal with the wiring box, so that the structure of the wiring box is simpler, the sealing effect of the wiring terminal installed in the wiring box is ensured, and the wiring terminal is more convenient to install through hard connection of the diverter on the wiring terminal and the circuit board. The connection strength of the diverter and the circuit board is ensured, the situation of disconnection between the binding post and the circuit board is avoided, and the quality of the ammeter is improved.

The application discloses a kind of wind power variable pitch system power grid fault detection method, system, terminal and medium, it is related to wind power generation technical field, its technical scheme main point is: by obtaining three-phase line voltage value detected by pitch driver, and based on the cosine law relationship between line voltage and phase voltage Mapping relationship is established, without increasing any external hardware voltage measurement module, only using the line voltage detection capability that driver has inside, i.e. By setting upper and lower threshold and comparing with line voltage, according to the preset judgment logic, it can be identified whether there is single-phase voltage anomaly in power grid and locate abnormal phase.Cose law reveals the inherent vector relationship between line voltage and phase voltage, when a certain phase voltage drops or rises, the two line voltages containing the phase will change simultaneously, while the third line voltage remains unchanged, by comparing the relative size of the three line voltages and the threshold, the abnormal phase can be uniquely determined.

The utility model relates to an electricity larceny prevention mutual inductor which comprises a base, a secondary junction box and a mutual inductor set, the mutual inductor set comprises two single-phase current mutual inductors and two single-phase voltage mutual inductors, and the mutual inductors are sequentially connected through connecting copper bars or wires; a terminal strip and a secondary binding post are arranged in the secondary junction box, lugs are arranged on the two sides in the secondary junction box, and internal threaded holes and internal threading holes are formed in the lugs; a concave lug is arranged on the inner side of a box cover of the secondary junction box, an outer threaded hole and an outer threading hole are arranged on the concave lug, the box cover is detachably fixed on the secondary junction box in the mode that the inner threaded hole and the outer threaded hole are fixed through screws, and a lead sealing anti-theft rope is arranged between the inner threading hole and the outer threading hole in a penetrating mode. According to the mutual inductor capable of preventing electricity larceny, the secondary junction box end is structurally optimized, private connection and electricity larceny can be effectively prevented in the mode that lead sealing is conducted firstly and then cover closing and fixing are conducted, meanwhile, the modular combination mode is adopted, a certain single-phase mutual inductor is convenient to disassemble, assemble, maintain and replace, and the use and maintenance cost is reduced.

The utility model belongs to the field of voltage transformers, and particularly relates to an outdoor secondary cast aluminum junction box single-phase voltage transformer. A secondary connecting terminal is arranged at the bottom of the side wall of a shell; a cast aluminum junction box is arranged at the bottom of the side wall of the shell; the secondary connection terminal is led out from the cast aluminum junction box, and the cast aluminum junction box is connected with the shell through a cast aluminum junction box fixing bolt. And the shell is formed by vacuum casting of outdoor epoxy resin. A fully-closed and fully-insulated structure is adopted, shielding treatment is carried out inside the structure, and the primary coil, the secondary coil and the iron core are packaged inside the shell. The voltage transformer is simple in structure, easy to install, good in safety, high in secondary protection level, low in material consumption and low in equipment cost, the safety of the voltage transformer is improved, the protection level can reach IP55, and the partial discharge level meets the international requirement.

The present invention provides a single-phase permanent magnet motor and a vacuum cleaner having the same. The single-phase permanent magnet motor includes a first type of stator teeth; a second type of stator teeth, the first type of stator teeth and the second type of stator teeth are arranged to form an accommodating cavity for accommodating a rotor portion; a gradient air gap thickness is formed between one of the first type of stator teeth and the second type of stator teeth and the rotor portion, and a uniform air gap thickness is formed between the other of the first type of stator teeth and the second type of stator teeth and the rotor portion. By providing two types of stator tooth structures and forming different air gap structures between the two types of stator teeth and the rotor portion, the electromagnetic torque and the cogging torque of the motor are staggered, thereby solving the problem of the starting dead point of the single-phase motor. Compared with a simple asymmetric tooth structure, this structure can greatly improve the starting ability of the motor, reduce the starting current of the motor, and eliminate the problem of the dead point of the motor starting in the prior art.

The invention provides a self-adaptive paver screed electric heating control method and system, and particularly relates to the technical field of engineering machinery electric control, and the method comprises the steps: obtaining the current value of each phase at the upper ends of a plurality of air switches in an electric heating control system in real time through a current monitoring unit; the logic control unit calculates the sum of each single-phase current, compares the sum with a preset overload current value and a preset protection current value, executes current state judgment, controls a contactor to be closed or outputs an alarm signal according to a judgment result, and closes the system; and meanwhile, for each air switch, calculating the current difference of any two phases under the same air switch based on the current value of each phase, comparing the current difference with a preset current difference value, and when the current difference is greater than the preset value, outputting a fault alarm signal and disconnecting the corresponding contactor. According to the method, the generator overload risk caused by overlimit of the heating power when the paver is adaptive to multiple types of screed plates can be avoided, and quick positioning of the open circuit fault of the heating strip is realized.

This invention relates to the field of single-phase power regulation technology, and more particularly to a multifunctional single-phase power regulator, comprising: a main circuit module for connecting the power supply and load and setting power regulation devices in series; an internal power supply and voltage regulation module that draws power from the main circuit and performs current limiting, rectification, and voltage regulation; a control and regulation module that generates control signals based on input signals and main circuit parameters under its power supply; a trigger suppression and synchronous start module that prohibits triggering before the power supply is stable or synchronization conditions are met; a protection monitoring module for monitoring main circuit parameters and prohibiting triggering in case of abnormalities; and a heat dissipation and maintenance module with an independent disassembly and assembly structure. In this invention, by drawing power from the main circuit and uniformly supplying power to the control and trigger modules for coordinated operation, control conditions are synchronously established when the main circuit is turned on, thereby improving the problem of false triggering and inconsistent start-up that easily occurs in traditional single-phase power regulators due to asynchronous power supply between the main control and the main circuit.

1. The name of the design product: single-phase electric energy meter calibrator. 2. The use of the design product: used for measuring the voltage, current, electric energy pulse and other signals of the electric energy meter, calculating the measurement error of the detected electric energy meter, and used for electric energy meter calibration. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: design 1 perspective view 1. 5. Design 1 is designated as the basic design. 6. Other circumstances that need to be explained: design 1 and design 2 are similar designs.

The application discloses a method for anti-electricity stealing based on abnormal connection of user single-phase electric meter, and relates to the technical field of electric power metering, which comprises the following steps: installing sampling units on the incoming line side and the outgoing line side of the user single-phase electric meter, synchronously collecting single-phase voltage, current, neutral line current and temperature and humidity signals of the meter box, and generating synchronous electrical data sequences through standardization and time stamp alignment. Single-phase voltage and current fundamental phase angles are calculated based on voltage and current instantaneous value sequences, and a phase angle difference map is constructed. The effective value of the neutral line current is calculated, and an abnormal flag sequence is generated in combination with a normal load reference range. The environmental temperature and humidity abnormal fluctuation period is extracted. The above-processed features are input into a connection mode recognition model to identify suspected electricity stealing connection mode categories, improve the accuracy of meter connection abnormality recognition, and reduce misjudgment. The method can effectively identify meter connection abnormalities and improve the accuracy of electricity stealing identification.

The utility model discloses a power supply protection device and a single-phase power supply device, comprising a rectifier bridge, two ends of an input side of the rectifier bridge are respectively connected with a live line and a zero line of an AC power supply, and two ends of an output side of the rectifier bridge are respectively connected with a bus capacitor unit and a load; the power supply protection device further comprises a pre-charging module which comprises an NTC pre-charging resistor and a PTC pre-charging resistor. The live wire comprises a first branch connected with the PTC pre-charging resistor and a second branch connected with the NTC pre-charging resistor; a zero sequence current transformer; the zero line and the first branch pass through the zero sequence current transformer and are connected with the rectifier bridge; the zero sequence current transformer is used for generating induced current according to the current conditions of the first branch and the second branch; the tripping protection module is respectively connected with the zero sequence current transformer and the alternating current power supply; the tripping protection module is used for making the live wire in an open-circuit state according to the induction current. Therefore, continuous heating of the PTC pre-charging resistor is prevented, and the situation that the product is burnt and even fire disasters are caused is avoided.

The application discloses a kind of three-phase unbalance treatment method, system, equipment and medium, belong to power quality treatment technical field, method includes: acquisition electrical parameter solution adjustment value;Single-phase electric energy is converted into direct current buffer storage;According to synchronous phase reconstruction distribution, the direct current electric energy is generated compensation current injection power grid.The system includes parameter acquisition and solution module, electric energy conversion and buffer module, reconstruction distribution module, compensation injection module.The application establishes target current solution logic by coupling three-phase unbalance degree and single-phase grid-connected feedback, utilizes direct current link to absorb single-phase fluctuation energy, and continuously injects three-phase compensation current in phase synchronous mode.The strategy will random single-phase power supply be converted into treatment tool, realizes cross-phase active reconstruction and smooth impact-free grid connection.

The utility model discloses an alternating-current variable-frequency power supply capable of realizing three-phase-to-single-phase full-power output, which comprises a main board, a slow starting module, a three-phase EMI (Electro-Magnetic Interference) filter, an R-phase output isolation transformer, an S-phase output isolation transformer, a T-phase output isolation transformer and a three-to-single interlocking switching contactor, the main board is provided with an output voltage sampling end pin, an output current sampling end pin, an SPP-107, an operation panel removing end pin, a driving signal end pin and a slow start removing end pin, and the main board is connected with the slow start module through the slow start removing end pin. The power supply does not need to additionally purchase single-phase power supply equipment and can be directly switched; compared with a voltage regulator scheme, a variable-frequency power supply is used for supplying power and is isolated from a mains supply power grid, so that the anti-interference performance is improved; an interlocking mechanism is arranged between the single phase and the three phases, so that the single-phase output and the three-phase output are prevented from being mistakenly connected, and the tested equipment is prevented from being damaged.