9134 results about "Alternate current" patented technology

The invention relates to the technical field of storage batteries, in particular to a storage battery monitoring, detection, treatment and evaluation integrated system and a storage battery management method, and the system comprises a plurality of accompanying modules, a collection power distribution control module, a storage battery management capacity checking host and a remote platform; the internal resistance analysis test of the system is based on multi-frequency-point alternating current excitation (0.5 Hz-7. 5kHz), a complex impedance spectrum of not less than 20 frequency points can be constructed, and the internal polarization characteristics of the battery are analyzed; the system adopts a feed network type discharge capacity checking, so that discharge electric energy is fed back to a power grid, and the capacity detection precision is improved to 98%; according to the system, EIS data and an LSTM neural network are fused, and a battery state of health (SOH) prediction model is established; the system is based on a DSP digital power supply technology, and can realize 50A active equalization topology.

The invention discloses a harbor shore power system oscillation damping suppression method based on heuristic probability optimization. According to the method, sliding window preprocessing is carried out on an alternating current bus side current time domain oscillation signal, modal decomposition is carried out based on a Prony algorithm, and modal energy is calculated to judge an oscillation mode; the discriminated oscillation modes are aggregated and mapped into equivalent circuit elements, a corresponding three-order circuit state matrix is constructed, and the damping ratio of each mode is determined according to the characteristic value of the matrix; taking a damping ratio as an evaluation index, introducing an influence factor to construct a multi-objective optimization function, parameterizing the parallel adjustable impedance, and limiting an adjustable range; and searching the control parameters by adopting a heuristic probability optimization strategy to obtain final damping control parameters, and downloading the final damping control parameters to the parallel adjustable impedance device to realize online dynamic adjustment. According to the method, multi-modal identification, physical magnitude mapping and online adaptive optimization can be realized, and the suppression capability and the operation stability of the shore power system on sub / super synchronous oscillation are improved.

The invention discloses a direct-current power transmission receiving end and a direct-current power transmission system. The direct-current power transmission receiving end comprises an inverter circuit and a receiving end transformer; the inverter circuit comprises a hybrid power grid commutation converter and a modular multi-level converter; a direct current first end of the hybrid power grid commutation converter is used for connecting a direct current power transmission line, a direct current second end of the hybrid power grid commutation converter is connected with a direct current first end of the modular multilevel converter, and an alternating current end of the hybrid power grid commutation converter is connected with a receiving end alternating current bus through a corresponding receiving end transformer; the direct current second end of the modular multilevel converter is grounded, and the alternating current end of the modular multilevel converter is connected with the receiving end alternating current bus through the corresponding receiving end transformer. In the embodiment of the invention, the hybrid power grid commutation converter and the modular multi-level converter which are connected in series are used at the direct-current transmission receiving end, so that the direct-current transmission receiving end has direct-current side fault ride-through capability and alternating-current side fault ride-through capability.

The invention discloses a wind-solar complementary energy storage direct current charging method and system based on liquid cooling heat dissipation, and relates to the technical field of energy storage charging. Comprising the following steps: S1, collecting wind-solar complementary energy storage data in real time, and carrying out data preprocessing; s2, converting wind-solar power generation into direct current, judging the flow direction of wind-solar power generation energy, and performing corresponding wind-solar power generation energy transmission power supply; s3, judging the limit of the output power of the charging pile, and controlling and adjusting the output of the charging pile in stages; s4, quantifying the liquid cooling flow required by heat dissipation, and performing heat source heat dissipation on the energy storage system and the charging pile; and S5, carrying out coordinated regulation and control, strategy optimization and multi-dimensional visualization on the flow direction of wind and light power generation energy, charging pile output and heat source heat dissipation. The problems that an existing charging station is difficult to deploy in remote and power transmission difficult areas, high-power charging heat dissipation and energy efficiency bottlenecks are prominent, and the efficiency of traditional air cooling and alternating current conversion is low, so that efficient, safe and green energy supplementation is difficult to achieve are solved.

The invention discloses a micro-grid power control method, system and device based on fuzzy modulation and a storage medium, and relates to the technical field of intelligent grid integration of a photovoltaic system and a micro-grid, and the method comprises the steps: firstly obtaining the real-time power data of a photovoltaic system, carrying out the control processing through fuzzy logic, and calculating a reference instruction; according to the reference instruction, hysteresis time is dynamically adjusted through modulation hysteresis control, and an inverter switching signal is generated; converting direct current into alternating current based on the switching signal and a power switching device, injecting the alternating current into the micro-grid, calculating active and reactive power reference values, ensuring that the system operates according to a unit power factor, and giving active power to the reference value; according to the method, the power control precision and adaptability of the micro-grid are improved, excessive switching of the inverter is avoided, loss is reduced, the service life is prolonged, power matching and stable transmission are achieved, reactive loss is reduced, bus voltage is stabilized, harmonic waves can be reduced, the electric energy quality is improved, and efficient and stable operation of the micro-grid is guaranteed.

The invention discloses a buried pipeline multi-source stray current interference coupling test system and test method. The system comprises a test pipeline module, a stray current simulation module, a cathode protection module, a multi-dimensional monitoring module, an intelligent protection module and a data analysis module. A comprehensive system integrating multi-source interference, a full-size pipeline, intelligent protection and real-time monitoring integrates static direct current interference, dynamic direct current interference and alternating current interference into the same system, and the problem that multi-source stray current superposition cannot be truly simulated in the prior art is solved. The comprehensive test of static direct current, dynamic direct current, alternating current stray current and anticorrosive coating defect coupling interference can be simulated, online monitoring of pipe-to-ground potential, current distribution and corrosion rate is realized, the timeliness and accuracy of test data are improved, cooperative work and data linkage analysis of multiple modules are realized, and the test efficiency is improved. A powerful basis is provided for optimizing a protection strategy, and the corrosion protection effect of the buried pipeline is improved.

The invention discloses an elevator energy-saving control system based on a conversion module, which relates to the field of elevator control and comprises a battery module, the conversion module and an energy-saving control module, the battery module is connected with at least one elevator; the AC side of the conversion module is connected with commercial power, and the DC side of the conversion module is connected with the battery module; the energy-saving control module is connected with the battery module, and the energy-saving control module is in communication connection with the battery module and the conversion module. The stable operation of the elevator is guaranteed, the electricity utilization economical efficiency of the elevator is effectively improved, and the electricity utilization cost is reduced.

The invention discloses a fault ride-through test method for an offshore wind power flexible direct output system, and the method comprises the steps: building a fault equivalent circuit of the offshore wind power flexible direct output system, analyzing the operation characteristics of an AC power grid side under a low-voltage fault, and determining the incidence relation between the DC side excess energy and the power grid voltage drop; establishing a model representing each component in the fault equivalent circuit, wherein the components at least comprise a machine-side converter, a grid-side converter, a direct-current capacitor and an unloading resistor; when a low-voltage fault of an alternating-current power grid side is detected, executing the following cooperative control based on the model: synchronously starting unloading resistance control and reactive power support control, wherein an unloading resistor dissipates excess energy of a direct-current side through a direct-current chopper; the grid-side converter injects a capacitive reactive current which is deeply matched with the voltage drop of the power grid so as to improve the voltage of a grid-connected point; and if the direct-current voltage continuously exceeds the preset threshold value, starting power prompt drop control, and reducing the output power of the unit according to a gradient until the system recovers to be stable.

The invention discloses an optimized reactive power control and fault ride-through method and system for a hybrid commutation converter, and the method comprises the steps: introducing reactive power control and considering the constant voltage control of negative turn-off angle limitation, achieving the control of an extremely low turn-off angle through the active turn-off of a full-control device in the converter under a steady-state working condition, and further meeting the demands of a high power factor; the investment of passive filter equipment is reduced; under the alternating current fault working condition, forced commutation and negative turn-off angle operation are achieved through active turn-off of a full-control device, the receiving end power grid voltage is effectively supported while commutation failure of a half-control thyristor in the hybrid commutation converter is avoided, and the active power transmission level during the fault period is improved. The full-control characteristic of the reverse blocking type integrated gate commutation thyristor in the hybrid commutation converter is fully utilized, reactive power control under the steady-state working condition and stable power transmission under the alternating-current fault are achieved by optimizing active turn-off control, and the method has wide applicability and good application prospects.

A combination includes a battery pack and an adapter. The battery pack includes a battery pack interface at least capable of being detachably connected to a power tool. A first adapter includes a plug, an alternating current input interface, an alternating current-direct current conversion circuit, and a direct current output interface. A second adapter is capable of being electrically connected to the first adapter and the battery pack. The second adapter includes an adapter interface, a direct current interface, a voltage conversion circuit, and a two-way control module. The direct current interface is configured to be detachably electrically connected to the direct current output interface. The voltage conversion circuit is connected in series between the direct current interface and the adapter interface. The two-way control module is connected between the direct current interface and the adapter interface and connected to the voltage conversion circuit.

The invention discloses a feedback type programmable alternating current source load integrated test system, and belongs to the technical field of power electronics. A feedback type programmable alternating current source load integrated test system comprises an alternating current power supply module, an alternating current load module, an energy feedback module, a control module and a test module. The system solves the problems that an existing test system can only provide a single power supply or load function, and excess energy cannot be effectively recycled in the test process, and through cooperative work of the alternating current power supply module, the load module and the energy feedback module, the test efficiency is improved, and the test cost is reduced. Programmable output of an alternating-current power supply, flexible simulation of load characteristics and efficient feedback of redundant electric energy are achieved, the flexibility and the resource utilization rate of the test are improved, the optimal design of the control module comprises the functions of data acquisition, control optimization, fault diagnosis and the like, the real-time performance, stability and reliability of the system are ensured, and the test efficiency is improved. And the load change and the fault condition can be quickly responded.

An intelligent energy management system, includes: a drive device including an engine configured to output power to a wheel of the vehicle, a drive motor configured to output power to the wheel, and an electric generator connected to the engine and driven by the engine to generate electricity; a power battery configured to supply electricity to the drive motor and charged with an alternating current outputted from the electric generator or the drive motor; and a control device configured to acquire multi-domain data fusion information, predict, according to the multi-domain data fusion information, a route-specific vehicle energy consumption corresponding to a preset travel route, plan, according to a road section-specific vehicle energy consumption corresponding to each road section, a target SOC corresponding to each road section, and control, according to the target SOC and an actual vehicle demand corresponding to each road section, the drive device.

The invention discloses an intelligent charging pile core module based on a VIENNA structure, an electric energy quality management method, system and equipment and a storage medium, and belongs to the field of electric power system energy storage equipment.The intelligent charging pile core module based on the VIENNA structure comprises the steps that an integrated power conversion unit is constructed, the power conversion unit adopts a VIENNA rectifier topology, three-phase alternating current is converted into direct current, and the direct current is converted into direct current; a harmonic suppression structure linked with the control interface is arranged; state information in the operation process is collected and serves as input of the control strategy module; based on the state information, a modulation control instruction is generated in the control strategy module to drive the switching action of the power conversion unit; on the basis of the modulation control instruction, the switch control is executed, meanwhile, the direct-current side midpoint potential of the power conversion unit is synchronously adjusted, and the distribution of direct-current bus capacitor voltage is controlled; and identifying the current operation condition according to the state information, switching to a control template corresponding to the operation condition in the control strategy module, and generating a modulation control instruction.

An embodiment apparatus for charging an electric vehicle includes a charging port, a detection block configured to generate a detection signal by detecting whether or not a charging connector of a charging facility is connected to the charging port, a charging controller configured to perform charging control using a first charging mode or a second charging mode according to the detection signal, and a relay box configured to separate charging power supplied from the charging facility into direct current power and alternating current power according to the charging control.

A multiple input converter for outputting power from AC power or a battery to positive and negative direct current (DC) buses is provided. The multiple input converter includes at least one bridge arm unit and a bidirectional DC-DC conversion unit. The bridge arm unit corresponds to one phase of the alternating current (AC) power and includes an upper and lower bridge arms that can independently form a two-level converter. In a battery mode, the upper and lower bridge arms discharge power from the rechargeable battery to the positive and negative DC buses, and the bidirectional DC-DC conversion unit discharges power from the rechargeable battery to the positive and negative DC buses or balances voltages of the positive and negative DC buses. In a mains mode, the bridge arm units are connected to the AC power. The bidirectional DC-DC conversion unit determine whether to charge or discharge according to load conditions.

The invention discloses a power grid transient stability margin prediction method based on steady-state power flow and anticipated faults, and the method comprises the steps: carrying out the sample generation based on different operation conditions of a power system, an AC power flow, operation modes under different time sequences, and faults under N-1 and N-2 scenes; labeling the generated sample according to two transient stability margin evaluation indexes of power angle stability and voltage stability; the labeled sample data and the anticipated fault data after the embedded coding are combined to serve as input features to be input into a deep learning model and trained, and a trained deep learning model is obtained; and predicting the transient stability margin of the power grid according to the trained deep learning model, and judging the stable state of the power system. The transient stability evaluation sample generation method is provided, the steady-state power flow and the expected fault before the fault are considered, the transient stability margin prediction of the power grid is realized by using the deep learning model, and the transient stability margin prediction speed, precision and reliability are improved.

The utility model relates to the technical field of acceleration sensors, in particular to a piezoelectric acceleration sensor, which comprises a shell, a mounting cavity is arranged in the shell, a shielding shell is fixedly connected in the mounting cavity, a crystal base is fixedly connected at the bottom end in the shielding shell, a PCB (printed circuit board) is arranged at the upper part in the shielding shell, and the crystal base is fixedly connected with the crystal base. An external force is applied along the polarization direction of the ceramic wafer to deform the ceramic wafer, the inside of the ceramic wafer is polarized, charges with opposite polarities appear on the two stressed end faces, and the ceramic wafer is recovered to an initial state if the external force is removed, so that mechanical energy is converted into electric energy by utilizing the direct piezoelectric effect of the ceramic wafer, and then the electric energy is subjected to signal processing; the sensor outputs 100mv / g alternating current voltage, so that vibration acceleration signals are measured, triangular shearing is adopted by a measuring element, a two-core shielding cable is adopted by a cable, and the sensor is small in size, light in weight and high in applicability.

The invention provides an electrolytic bath impedance measurement method and system considering dynamic disturbance, and relates to the field of electrochemical equipment, and the system comprises a direct current power supply module which is used for providing a direct current power supply for an electrolytic bath; the parameter optimization module is used for determining an optimal disturbance frequency band and an optimal disturbance parameter according to the working condition of the electrolytic cell and the equivalent circuit model of the electrolytic cell; the alternating current disturbance module is used for injecting a dynamic disturbance signal to the electrolytic cell according to the optimal disturbance frequency band and the optimal disturbance parameter; the feedback acquisition module is used for acquiring feedback data of the electrolytic bath on the dynamic disturbance signal; and the impedance analysis module is used for calculating the impedance of the electrolytic cell based on the feedback data, and has the advantage of realizing accurate measurement of the impedance of the electrolytic cell under the dynamic working condition.

The present disclosure provides a method for driving a cholesteric liquid crystal display device. The method includes the following steps: utilizing a driving circuit section to sequentially activate each scanning electrode within a display panel; utilizing the driving circuit section to apply first alternating-current (AC) voltage pulses to pixel circuits on an activated scanning electrode during a first stage within a pulse-width modulation (PWM) scanning procedure of an activated scanning electrode; and utilizing the driving circuit section to apply second AC voltage pulses to the pixel circuits on the activated scanning electrode during a second stage of the PWM scanning procedure. A first voltage amplitude and a first period of the first AC voltage pulses are different from a second voltage amplitude and a second period of the second AC voltage pulses, respectively.

The invention relates to the technical field of micro-grids, in particular to an alternating current and direct current hybrid micro-grid cooperative control method. According to the technical scheme, the alternating current and direct current hybrid micro-grid cooperative control method comprises the following steps that S1, a multi-stage micro-grid framework is constructed and comprises a main micro-grid, a direct current sub-micro-grid and an alternating current sub-micro-grid, and the main micro-grid and the direct current sub-micro-grid are connected through a bidirectional interconnection converter; s2, deploying a hierarchical Multi-Agent control architecture, wherein the hierarchical Multi-Agent control architecture comprises a main micro-grid agent, a direct current sub-micro-grid agent and an alternating current sub-micro-grid agent; and S3, executing three-level cooperative control, receiving a main network scheduling instruction by the main micro-grid agent, decomposing the main network scheduling instruction into sub-micro-grid control targets, coordinating power distribution among sub-micro-grids based on a global optimization algorithm, and maintaining voltage and frequency stability by the DC sub-micro-grid agent and the AC sub-micro-grid agent through a local control algorithm. According to the method, the power grid consumption efficiency and the operation stability in a high-proportion new energy access scene are remarkably improved.

The invention provides a device and method for testing the reliability of a power sensor, and the device comprises a magnetic field generation unit which is used for providing an alternating current for a Helmholtz coil through a power frequency current source, and generating a controllable magnetic field; the electric field generating unit is used for providing a high-voltage direct current or power frequency alternating current power supply for the parallel-plate capacitor through a high-voltage generator to generate a uniform electric field; the tested unit is used for providing a standard excitation signal through a standard source matched with the to-be-tested sensor, simulating an input condition of the to-be-tested sensor under an actual working condition and collecting output data of the to-be-tested sensor; and the control unit is used for setting test parameters, generating a control instruction according to the test parameters and generating a test result according to the output data. According to the device and the method, by simulating a strong magnetic field and a strong electric field environment and combining application of various measured parameters and an automatic control system, the reliability evaluation requirement of the sensor under the actual working condition is fully met.

The invention relates to the technical field of automobile charging, and particularly discloses a vehicle circuit system with a reverse charging function, comprising a main battery pack; the bidirectional inverter is electrically connected to the main battery pack and is configured to convert external alternating current into direct current to charge the main battery pack in a charging mode and convert the direct current of the main battery pack into alternating current to be output in a discharging mode; the charging control module is connected to the output end of the bidirectional inverter and used for processing input / output electric energy of different specifications; the multifunctional output interface comprises at least one alternating current interface and a direct current interface; and the system control unit, the integrated current detection module, the temperature monitoring module and the fault diagnosis module are respectively in communication connection with the bidirectional inverter, the charging control module and the output interface through a CAN bus. The vehicle power battery can reversely supply power to external equipment or other vehicles, meanwhile, the conventional charging function and the energy recycling function are compatible, and the method is suitable for new energy vehicles, hybrid electric vehicles and other scenes.

The invention discloses an alternating current arc detection method based on current and harmonic wave fluctuation and a related device, and the method comprises the steps: collecting first electrical signal data at a preset position in a target power grid, extracting harmonic wave features in the first electrical signal data, collecting second electrical signal data at the preset position, and extracting current waveform features in the second electrical signal data; determining a dichotomy feature data set and a fluctuation feature data set according to the harmonic features and the current waveform features; training a preset model based on the dichotomy feature data set and the fluctuation feature data set to obtain a dichotomy model and a fluctuation model; and performing arc fault detection on the electrical signal of the preset second time period at the preset position through a dichotomy model and a fluctuation model to determine a target arc fault detection result at the preset position. According to the invention, the arc fault detection is carried out through the combination of the binary classification model and the fluctuation model, and the detection accuracy of the fault arc can be improved.

The invention discloses a lithium battery solid electrolyte interface film forming quality evaluation method. The method comprises the following steps: in a lithium battery formation stage or a circulation process, applying an alternating current disturbance signal with an amplitude of 1-20mV, and collecting full-band electrochemical impedance spectroscopy data in real time; a relaxation time distribution method is adopted to decouple the electrochemical impedance spectrum of the intermediate frequency region; constructing an equivalent circuit model containing SEI film characteristics, and fitting the decoupled electrochemical impedance spectrum curve by the equivalent circuit model; the compactness index of the SEI film is calculated according to the SEI film resistance and the film capacitance, and whether the compactness of the SEI film reaches the standard or not is judged according to the compactness index; and calculating a lithium ion diffusion coefficient by combining the charge transfer resistance and the Warburg diffusion impedance, and evaluating the SEI membrane ion transmission efficiency. According to the invention, non-destructive monitoring is supported, quantitative evaluation of SEI membrane compactness, ionic conductivity and short circuit faults in the module can be realized, and the cycle life and safety of the lithium battery are improved.

The invention discloses a voltage acquisition circuit, an alternating current power supply, a voltage acquisition method, a voltage acquisition device and a medium. A far-end sampling unit; the in-phase input end of the first comparison unit is connected with the near-end sampling unit, and the inverted input end is grounded; the in-phase input end of the second comparison unit is connected with the far-end sampling unit, and the inverted input end is grounded; the input end of the XOR unit is connected with the output ends of the first comparison unit and the second comparison unit; the in-phase input end of the third comparison unit is connected with the output end of the XOR unit, the inverted input end inputs reference voltage, and the reference voltage is smaller than half of the power supply voltage; the control unit is used for judging that far-end sensing sampling is abnormal when the difference effective value of the voltages output by the near-end sampling unit and the far-end sampling unit is smaller than the preset compensation voltage and the abnormal comparison voltage output by the third comparison unit is 1. According to the invention, when the AC power supply outputs low voltage, the conditions of disconnection and reverse connection of the far-end induction sampling can be identified.

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.

An elevator energy-saving control system of a direct feed network relates to the technical field of elevator energy-saving control, and comprises an energy conversion module for converting kinetic energy and gravitational potential energy generated during operation of an elevator car into direct current; the control system module monitors elevator running state data and power grid parameters in real time, judges whether the elevator is in a power generation state or not according to a monitoring result, automatically starts an energy feedback mode and controls starting and stopping of energy feedback and power adjustment; the inversion grid-connected module is used for converting the direct current into alternating current, processing the generated alternating current and feeding back the electric energy in the form of the processed alternating current to a power grid; and the man-machine interaction module is used for receiving data information of the control system in real time and converting the data information into visual display content, so that a worker can master the operation condition of the system in time and deal with abnormal problems. The elevator running energy consumption is remarkably reduced, the running cost is reduced, meanwhile, the service life of equipment is prolonged, the stability of the equipment is improved, and the influence on the environment is reduced.

The invention discloses a method and a system for measuring the real-time short-circuit ratio of a new energy station based on Kalman filtering. The method comprises the following steps: constructing a Thevenin equivalent circuit of a new energy station connected to an alternating current system; inputting a reference voltage into the Thevenin equivalent circuit, and measuring two groups of voltages and currents of the grid-connected point at different moments; filtering the measured voltage and current values by using Kalman filtering; calculating system parameters of the Thevenin equivalent circuit by using the filtered voltage and current values; and calculating the real-time short-circuit ratio of the new energy station according to the system parameters of the Thevenin equivalent circuit. The problem that the real-time short-circuit ratio of the system is difficult to accurately measure due to the fact that large-scale new energy is connected to the power system at present can be solved.

The invention discloses an electromagnetic valve fault diagnosis method and system, a storage medium and a program product, and relates to the field of magnetic variable measurement, in the method, an alternating current signal of a first preset frequency is applied to an electromagnetic valve coil, an inherent working current signal is collected, and a mixed current signal is generated; separating the mixed current signal to obtain a harmonic component; determining a target frequency based on the harmonic component; generating an excitation current signal of a second preset frequency according to the target frequency; applying an excitation current signal to a solenoid valve coil, and collecting a resonance current signal generated by the solenoid valve under the excitation current signal; determining the resonance characteristic of the internal mechanical structure of the electromagnetic valve according to the amplitude and the phase characteristic of the resonance current signal; and identifying the fault type of the electromagnetic valve based on the change trend of the resonance characteristic along with time. The method is used for improving the accuracy of identifying the evolution trend of the fault features, further preventing possible faults of the electromagnetic valve in advance, and improving the safety of the electromagnetic valve in the using process.

The invention relates to the technical field of alternating current grid-connected operation countercurrent prevention, in particular to an alternating current countercurrent prevention method which has the advantages that the structure is simple, and countercurrent can be completely prevented; comprising alternating current positive and negative half-cycle phase sampling driving control, a power switch tube and an ideal diode or a universal diode. An alternating current input is connected to the alternating current positive and negative half-cycle phase sampling driving control part for sampling and is connected to the power switch tubes for providing power input, and the alternating current positive and negative half-cycle phase sampling driving control part outputs two paths of signals to respectively drive and control the corresponding power switch tubes. The output of the switching tube passes through the ideal diode or the universal diode and then outputs respective positive half-cycle and negative half-cycle alternating current in parallel.