306results about "Conversion with intermediate conversion to dc" patented technology

The invention relates to the technical field of frequency converter harmonic control, in particular to a harmonic control method, system and device applied to a frequency converter, and the method comprises the steps: obtaining the current data of a rectification input side and an inversion output side of the frequency converter; obtaining the difference coefficient of the overall pulsation amplitude change of each period and the irregular coefficient of the corresponding pulsation time change, and further obtaining the harmonic influence coefficient of the rectification input side current of each period with the pulsation amplitude difference and irregular characteristics; calculating a deviation coefficient and a jitter abnormal coefficient of the inversion output side current of each period so as to obtain a harmonic influence coefficient of the inversion output side current of each period having waveform deviation and rapid jitter; therefore, the harmonic delay superposition interference coefficient is obtained, and the output current of the inverter is corrected in combination with the current data of the inverter output side. The harmonic control precision of the frequency converter can be improved.

The invention discloses a power supply system, and relates to the technical field of electrical connection devices, and the power supply system comprises a power supply input end which is used for accessing commercial power; the power supply output end is used for accessing a load; the rectifying circuit and the inverter circuit are sequentially connected in series between the power input end and the power output end; the first switching circuit is connected in series between the power supply input end and the input end of the rectifying circuit; the input end of the energy storage circuit is connected with the output end of the first switching circuit, and the output end of the energy storage circuit is connected with the input end of the inverter circuit; the control unit is respectively connected with the controlled end of the first switching circuit and the controlled end of the energy storage circuit; the invention aims to reduce the economic burden of electricity utilization of the user.

A power management system for an elevator system. A power management system for an elevator system includes a power converter having three input terminals, two of the three input terminals coupled to a main power source for supplying single-phase AC power to the power management system, the power converter configured to convert the AC power from the main power source into DC power on a common DC bus, a secondary power source for supplying DC power to the common DC bus, a power inverter configured to invert the DC power on the common DC bus into AC output power for driving an electric motor of the elevator system, and a dynamic braking resistor which is coupled between a third input terminal among the three input terminals of the three-phase power converter and the common DC bus.

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

A noise reduction circuit includes: noise canceler circuitry configured to inject a compensation current into a power line and ground to reduce a common mode noise current that flows through the power line and the ground into a commercial power supply from a power converter with a switching element connected to the commercial power supply; and overcurrent inhibitor circuitry provided on a compensation current path through which the compensation current flows, the overcurrent inhibitor circuitry being configured to inhibit application of an overcurrent to the noise canceler circuitry.

Provided are a power supply circuit and a power supply system. In the power supply circuit, a main circuit output module includes a first DC / DC converter and a first DC / AC inverter, and a conversion module is configured to output DC power to the first DC / DC converter according to input AC power. The first DC / DC converter is configured to convert the DC power into a constant DC voltage, and output the constant DC voltage to a first DC / AC inverter. The first DC / AC inverter is configured to acquire first supplied electrical energy by converting the constant DC voltage into AC power, and output the first supplied electrical energy.

The invention provides a hybrid distribution transformer low-voltage turn-on overcurrent protection device and protection strategy combined with a current limiter, and the device comprises a hybrid distribution transformer which is composed of a power frequency electromagnetic part and a high-frequency power electronic part, and the power frequency electromagnetic part comprises a power transformer and a series transformer. The high-frequency power electronic part comprises converters which are connected back to back; the saturated iron core fault current limiter is integrated in a main loop of the hybrid distribution transformer, presents low impedance during normal operation, and is switched to a high impedance state through iron core desaturation to limit fault current during fault; the bypass switch module is connected to the input side of the high-frequency power electronic part, and when the fault current exceeds a set threshold value, the bypass switch module is conducted to bypass and isolate the high-frequency power electronic part within less than or equal to 1ms, and the continuous power supply of the power-frequency electromagnetic part is maintained; and the fault isolation device is configured at the two ends of the hybrid distribution transformer, and performs breaking operation in response to the current setting value and the low voltage setting value after current limiting so as to realize fault area isolation.

The invention discloses a radio frequency power supply for maintaining a remote plasma source, and the power supply comprises a three-phase rectification filtering module which is used for converting an obtained first AC electric signal into a DC electric signal, eliminating the noise and clutter interference in the DC electric signal, and providing a power signal for a subsequent circuit through the DC electric signal; the full-bridge LCL-T resonant inversion module is used for converting the direct-current electric signal into a second alternating-current electric signal with a preset frequency according to the pulse signal output by the driving control module and transmitting the second alternating-current electric signal to a load end; and the driving control module is used for outputting a pulse signal to control the full-bridge LCL-T resonant inversion module so as to realize a preset alternating current frequency. According to the radio frequency power supply for maintaining the remote plasma source, generation of plasmas can be maintained when the power supply frequency is at the preset power, the coupling efficiency of the power is improved, and heat generated in the operation process of the plasma source is reduced.

The invention relates to the technical field of electrical equipment testing, and discloses a high-precision anti-interference intelligent transformer short-circuit impedance testing machine which comprises an isolation power supply module and a testing host module, an electrostatic shielding layer is arranged in the isolation power supply module, a suspension working power supply isolated from power grid noise is provided for a testing host, and the anti-interference capability is improved from the source. The test host module integrates a power management and inversion module to generate a controllable three-phase AC excitation signal, and the central processing and control module performs closed-loop feedback control on a test current according to a high-precision synchronously acquired signal, so that an external voltage regulator is replaced, and automatic stabilization of a test condition is realized. According to the invention, tedious manual adjustment is not needed, full automation of the testing process is realized, and the precision, repeatability and safety of short-circuit impedance testing are remarkably improved.

The invention discloses a hybrid distribution transformer fusing an on-load tap changer and a series-parallel converter and a voltage control method, and belongs to the technical field of intelligent power distribution. The hybrid distribution transformer comprises a primary winding, a secondary main winding, a secondary series winding, an on-load tap changer, a series-parallel converter and a unified coordination controller, the parallel side of the parallel converter is connected to the output end of the secondary main winding, and compensation voltage is injected into the series side of the parallel converter through the secondary series winding. The voltage control is based on a voltage deviation and three-phase voltage unevenness hierarchical decision-making method, and the low-speed large-range voltage regulation of the on-load tap changer and the rapid and accurate compensation of the series-parallel converter are dynamically coordinated. The method has the high capacity advantage of an on-load tap changer and the quick response characteristic of a power electronic device, can synchronously solve the problems of long-term voltage deviation and instantaneous voltage fluctuation in the power distribution network, reduces the equipment cost and maintenance cost, and is suitable for voltage stabilization and electric energy quality optimization of the intelligent power distribution network.

The invention discloses an atmosphere plasma generator, which comprises a driving power supply and a spray gun, and is characterized in that the driving power supply comprises a rectifier, at least two half-bridge inverters and at least two transformers in one-to-one correspondence with the half-bridge inverters; the input end of the rectifier is connected with an AC power supply; the at least two half-bridge inverters are arranged at the output end of the rectifier in parallel; the primary side of each transformer is connected with the output end of the corresponding half-bridge inverter, the secondary sides of the multiple transformers are connected in series to form an output port, and the output port is connected with the spray gun. According to the atmospheric plasma generator, the specification requirement on a single related power device is reduced, so that higher total power output can be realized, the requirement of equipment such as the plasma generator on high voltage of several kilovolts can be met, and the controllability and adaptability of voltage output are improved. And when the power demand is increased, flexible expansion can be realized by increasing the number of the parallel modules, the whole system does not need to be redesigned, and the power expansion capability is improved.

A first controller includes a first processor and a first memory. A second controller includes a second processor and a second memory. In transmitting data from the first controller to the second controller, the first controller repeatedly performs a write operation of writing transmitted data into the first memory in accordance with a clock signal, and reads the transmitted data from the first memory and outputs the transmitted data. The second controller writes the received data into the second memory in accordance with the clock signal, and reads the received data from the second memory in accordance with the clock signal. When a plurality of data values of the received data read from the second memory match each other in a plurality of consecutive clock cycles including a current clock cycle, the second controller transmits the data value of the current clock cycle to the second processor.

The present invention relates to a submodule for a semiconductor transformer in single packaging with reduced partial discharge quantity and excellent insulation performance that is capable of applying an equipotential structure for each stage of the submodule for the semiconductor transformer to further improve insulation performance by reducing partial discharge quantity in the semiconductor transformer while improving insulation performance by securing separation distance between a high voltage unit and a low voltage unit in the semiconductor transformer.The submodule for semiconductor transformer in single packaging with reduced partial discharge quantity and excellent insulation performance in the present invention comprises: a high voltage unit for converting high-voltage low-frequency AC power into high-frequency AC power; a transforming unit for converting the high-voltage AC power into low-voltage AC power; and a low voltage unit for converting the low-voltage AC power into low-voltage DC power.

The invention discloses a frequency control method of a variable-frequency power supply. The method comprises the following steps: step 1, collecting multi-source information; 2, generating a dynamic frequency reference; 3, calculating a predictive control quantity; 4, self-adaptive compensation correction is carried out; and step 5, pulse width modulation output. The state of the variable-frequency power supply is sensed comprehensively through multi-source information collection, and data support is provided for accurate control; dynamic frequency reference generation and predictive control quantity calculation are adopted, rapid and accurate frequency control is achieved, and response delay and static errors are reduced; a self-adaptive compensation correction and pulse width modulation output mechanism is constructed, the adaptability to complex working conditions is enhanced, harmonic oscillation is suppressed, compared with the prior art, the response speed, the control precision and the adaptability are remarkably improved, and stable and efficient operation of the variable-frequency power source is guaranteed.

The invention relates to the field of converters, and discloses a traction converter and a cooling system thereof, and the traction converter comprises at least one rectification module which is used for converting alternating current into direct current, and all bridge arms in the at least one rectification module can be equally divided into a first bridge arm group and a second bridge arm group; the at least two inversion modules are used for converting direct current into alternating current, each inversion module comprises a three-phase bridge arm, and all the bridge arms in the at least two inversion modules can be equally divided into a third bridge arm group and a fourth bridge arm group; the first cooling plate is provided with a first rectification-inversion module, and the first rectification-inversion module comprises a first bridge arm group and a third bridge arm group; and the second cooling plate is provided with a second rectification-inversion module, and the second rectification-inversion module comprises a second bridge arm group and a fourth bridge arm group. In this way, the cooling system can be designed in a light-weight mode, and light weight of the traction converter is achieved.

The utility model discloses a low-power-consumption high-efficiency main transformer integrated board for an air-cooled refrigerator, which comprises an X capacitor discharge circuit, a variable-frequency power supply circuit, a bus voltage sampling circuit, a mains supply voltage sampling circuit and an IGBT (Insulated Gate Bipolar Translator) driving circuit, and is characterized in that the X capacitor discharge circuit uses a discharge chip to replace a traditional discharge resistor; the variable-frequency power supply circuit is additionally provided with a variable-frequency power supply switch circuit, the bus and commercial power voltage sampling circuit modifies the resistance value of a divider resistor, and the IGBT driving circuit modifies the resistance value of a resistor. According to the utility model, improvement is made on the basis of a traditional air-cooled refrigerator main transformer integrated plate, the standby power consumption and the operation power consumption of the main transformer integrated plate are reduced, and the low-power-consumption and high-efficiency electric control design is realized.

The invention relates to a heat pump, in particular for use in a HVAC system, comprising, as part of a working circuit of the heat pump, at least one compressor device (1) for compressing a working medium of the working circuit, wherein the compressor device (1) in turn comprises an electric motor (32) for providing a mechanical movement for compressing the working medium, an inverter (31) which supplies the electric motor (32) with alternating current, a rectifier (11) which supplies the inverter (31) with direct current, wherein the rectifier (11) can be connected to an alternating current source in order to supply power to the compressor device (1), and a monitoring device (12) for monitoring an operating state of the electric motor (32), which monitoring device comprises at least one measuring means (122, 123) for detecting an operating variable of the compressor device (1) and an evaluation means (121) for evaluating the detected operating variable, wherein the electric motor (32) and the inverter (31) supplying same with alternating current are jointly integrated in a DC compressor unit (30) of the compressor device (1), which is coupled via a DC interface (20) to an electronics unit (10) of the compressor device (1) which is separate from said DC compressor unit and in which, in turn, the rectifier (11) and the monitoring device (12) are jointly integrated.

A motor drive device (1) comprises a control unit (20) that controls the operation of an inverter circuit (11), as well as a current sensor (22) and a bandpass filter (13), which together form a sensing unit for detecting a ripple current flowing to a smoothing capacitor (10). The control unit (20) comprises a current waveform sensing unit (12) that detects a current waveform and a current value of the ripple current based on a sensing value from the sensing unit.The control unit (20) performs a first determination operation to establish a threshold for the current value of the ripple current detected by the current waveform detection unit (12), using a first threshold value. It then performs a second determination operation to establish a threshold for a specific frequency component included in the current waveform of the ripple current, using a second threshold value. Based on the results of the first and second determination operations, the control unit (20) determines whether to decrease the degree of torque control to change a motor current in accordance with a change in the load torque of a motor (4a), or whether to decrease the motor speed of the motor (4a), and controls the torque control degree or the motor speed accordingly.

The application provides a pre-charging method and system of a motor train unit traction auxiliary converter, the method comprising: closing an output contactor in the traction auxiliary converter according to a received contactor closing instruction; if no pre-charging instruction is received, judging whether to perform a pre-charging process on a direct current capacitor in the traction auxiliary converter according to a voltage of the direct current capacitor and a preset rated voltage; if yes, obtaining three-phase alternating current voltages and three-phase alternating current of an alternating current port of an auxiliary inverter in the traction auxiliary converter, determining active current feedback values and reactive current feedback values, and generating a pulse signal, and sending the pulse signal to the auxiliary inverter, so that an output voltage of a direct current port of the auxiliary inverter reaches the rated voltage. The application realizes the pre-charging function of the converter without increasing the hardware of the converter, reduces the cost, improves the availability of the converter, reduces the current impact of the switching device and the action frequency, helps to improve the service life and reduce the failure rate.

The invention relates to the technical field of switching power supplies, in particular to a variable-frequency switching power supply system. The system comprises a first voltage conversion module used for converting a first AC voltage input by an AC power supply into a first DC voltage, and inputting the first DC voltage into a second voltage conversion module; the digital signal processing module is used for acquiring a first reference frequency and performing closed-loop control on the second voltage conversion module based on the first reference frequency, so that the second voltage conversion module converts the first direct-current voltage into a voltage wave controlled by a bipolar pulse width modulation signal corresponding to the first reference frequency; and the frequency selection filtering module is used for acquiring a second reference frequency, and performing frequency selection filtering on the voltage wave controlled by the bipolar pulse width modulation signal input by the second voltage conversion module based on the second reference frequency to obtain a second AC voltage corresponding to the second reference frequency. By adopting the scheme, the variable-frequency switching power supply system which is simple in structure and high in reliability and flexibility can be provided.

A frequency converter comprises a box body, a rectification module, a first capacitor module, a first inversion module, a control module, a plurality of vertical partition plates and a plurality of conductive busbars, the vertical partition plates divide the interior of the box body into a first cavity, a second cavity and a third cavity from left to right at a time, and the rectification module is arranged on the lower portion of the first cavity; the first capacitor module is arranged at the upper part of the first cavity, the first inversion module is arranged in the second cavity, the control module is arranged in the third cavity, the rectification module and the first capacitor module, and the first inversion module and the first capacitor module are connected through a conductive busbar. The frequency converter is reasonable in arrangement, compact in structure, small in size, large in power density, stable, firm and reliable in structure, convenient to install and transfer, and very high in efficiency.

The invention provides a real-time dynamic control method and system for harmonic compensation of a frequency converter, and the method comprises the steps: obtaining an input current at a first current sampling point through initializing harmonic compensation processing parameters of the frequency converter, the harmonic compensation processing parameters comprising the size of a sliding window and the sliding step length of the sliding window; generating an injection current based on the input current at the first current sampling point, injecting the injection current into a compensation current injection point, obtaining an output current at the second current sampling point, and evaluating the dynamic offset of harmonic compensation dislocation in the current time window according to the harmonic proportion in the output current at the second current sampling point, and the compensation time of the next time window is adjusted according to the dynamic offset of the current time window, so that adverse effects caused by harmonic compensation signal dislocation can be effectively reduced.

The utility model discloses a resonant filter circuit, a device and a frequency conversion device, and relates to the field of circuits, when a frequency conversion system controls a compressor to start, a controllable switch is switched on, an LC filter module is connected to a circuit between an AC power supply and the frequency conversion system, harmonic waves generated in the circuit are filtered, and the frequency conversion system is switched on. The harmonic current content in the air conditioner subsystem is reduced; and when the frequency conversion system does not control the compressor to start, the controllable switch is kept switched off, and the LC filter module is not put into use, so that the consumption of reactive power by the capacitor is avoided. Whether the LC filter module is put into use or not is controlled by switching on and switching off the controllable switch, harmonic suppression is carried out on the working frequency conversion system, meanwhile, voltage loss and electric energy loss caused by the fact that the LC filter module is connected into the circuit when the frequency conversion system does not work are avoided, and reactive power consumption of the whole circuit and the frequency conversion system is reduced.

The present invention relates to the field of ultrasonic power supply technology, and in particular to a high-frequency ultrasonic power supply, a control method thereof, and a high-frequency ultrasonic device. A sampling circuit measures the actual output voltage and current and calculates the actual power of the load; a power controller generates a voltage control instruction based on the difference between a set power threshold and the actual power of the load, and limits it through a power limiter; a voltage controller generates a current control instruction based on the difference between the voltage control instruction output by the voltage controller limiter and the actual output voltage, and limits it through a voltage limiter. A current controller generates a drive control signal based on the difference between the current control instruction output by the current controller limiter and the actual output current, and limits it through a duty cycle limiter; the drive control signal output by the duty cycle limiter adjusts the duty cycle of the switching tube of the DC / DC converter, thereby adjusting the actual power, current, and voltage of the load. The present invention enables the power supply to always meet the control requirements of voltage, current, and power.

The invention discloses a simplified non-isolated cascade type power electronic transformer and system with no load, and belongs to the field of transformers, the power electronic transformer comprises a cascade structure formed by a plurality of rectification and inversion modules, the front stage of the cascade structure is a cascade rectification structure, and the rear stage of the cascade structure is a cascade inversion structure; the cascade structure comprises at least one no-load module, and the no-load module is arranged at the head end or the tail end of the cascade structure; when the number of the rectification inversion modules is 3, the other two rectification inversion modules are three-bridge-arm modules; and when the number of the rectification and inversion modules is greater than 3, the rectification and inversion module between the two three-bridge-arm modules is a two-bridge-arm module. According to the invention, a part of switching tubes in the non-isolated power electronic transformer with the no-load module are canceled, so that the cost of the converter can be reduced and the working efficiency can be improved on the premise of ensuring the original working range.

The embodiment of the utility model discloses a power supply module and an integrated power supply system, the power supply module comprises a first shell, a first power supply, a second power supply and a heat insulation piece, and the first shell comprises a containing cavity; the first power supply is arranged in the accommodating cavity of the first shell, the first power supply comprises a first rectification module, and the first rectification module is used for receiving alternating current input and outputting first direct current voltage; the second power supply is arranged in the accommodating cavity of the first shell, the second power supply and the first power supply are arranged at an interval, the second power supply comprises a second rectification module, and the second rectification module is used for receiving alternating current input and outputting second direct current voltage; the heat insulation piece is arranged between the first power source and the second power source and used for reducing heat conduction between the first power source and the second power source. By arranging the heat insulation piece, heat conduction between the first power supply and the second power supply can be reduced, and mutual influence between the first power supply and the second power supply is reduced as much as possible.

The motor drive device comprises: a pre-charge resistor that suppresses an inrush current during the pre-charging of a capacitor provided at a DC intermediate stage on the DC output side of an inverter; a pre-charge switch connected in parallel to the pre-charge resistor; a voltage sensing unit that detects the value of an input voltage; an input switching unit that selectively switches the voltage to be input to the voltage sensing unit between a first voltage, which is a voltage of the pre-charge resistor, and a second voltage, which is a voltage other than the voltage of the pre-charge resistor; and a fault detection unit that determines, based on the voltage value detected by the voltage sensing unit, whether or not there is a fault in the pre-charge switch.

The present disclosure provides a drive control device for a compressor of an air conditioning system which is capable of complying with the standard for harmonics in the power grid. A drive control device for a compressor of an air conditioning system, comprising: a three-phase bridge circuit or three-phase rectifier circuit that rectifies a three-phase alternating voltage from a three-phase mains supply; an LC filter circuit that smooths the output of the three-phase bridge circuit or three-phase rectifier circuit; an inverter circuit that is supplied with electrical power by the LC filter circuit and provides drive power to a drive motor of a compressor arranged in the air conditioning system; and a control unit that regulates the inverter circuit, wherein for a cutoff frequency FC of the LC filter circuit the following expression (A) applies: α × FA ≤ FC ≤ FU where the frequency FA is the frequency of the three-phase mains supply and the coefficient α is 14 or more, and the upper limit FU is a frequency at which the LC filter circuit cuts off or suppresses the sixth harmonic of the fundamental frequency of the compressor's drive motor by a first fraction or percentage or more.

Frequency converter (100), comprising: - an inverter (1) with a number of power semiconductors (7-12), wherein the inverter (1) is designed to control the power semiconductors (7-12) in a clocked manner such that a number of control signals (u, v, w) with a predetermined time profile are generated for controlling an electric motor (2), - terminals (13, 14, 15) at which the number of control signals (u, v, w) is output, and - a partial discharge detector (16) designed to detect partial discharges occurring in lines (17, 18, 19) between the frequency converter (100) and the electric motor (2) during the clocking of the power semiconductors (7-12), - wherein the partial discharge detector (16) comprises a partial discharge sensor (3) which is designed to extract partial discharge signals (TS) from signals present at the terminals (13, 14, 15) of the frequency converter (100).

The invention discloses a flash power supply and a railway signal power supply system. The flash power supply comprises an AC input circuit, a voltage comparison circuit, a logic control circuit and an AC output circuit. The alternating-current input circuit is connected with the voltage comparison circuit and used for receiving an alternating-current voltage signal output by an alternating-current power supply AC, converting the alternating-current voltage signal into a direct-current voltage signal and outputting the direct-current voltage signal to the voltage comparison circuit; the voltage comparison circuit is respectively connected with the alternating current input circuit, the logic control circuit and the alternating current output circuit; and the alternating current output circuit is connected with the logic control circuit and is used for periodically outputting alternating current voltage signals to external electric equipment. According to the flash power supply and the railway signal power supply system, the design is scientific, the external input alternating current voltage signal can be periodically output after passing through the voltage comparison circuit, the logic control circuit and the output overcurrent protection circuit, a power supply can be reliably provided for electric equipment, and normal use of the electric equipment is guaranteed.