125results about "Conversion with intermediate conversion to dc" patented technology

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.

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 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.

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 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.

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.

The utility model discloses a bus residual electricity recycling circuit after spark, the residual electricity recycling circuit is applied to a power supply circuit of an electric precipitator, the power supply circuit comprises a rectification voltage regulation module, a filter inductor L, a bus filter capacitor C0 and a load module, the input end of the rectification voltage regulation module is used for connecting 380V alternating current voltage, and the output end of the rectification voltage regulation module is used for connecting the filter inductor L with the bus filter capacitor C0. A first output end of the rectification voltage regulation module is connected with a first end of the filter inductor L, a second end of the filter inductor L is respectively connected with a first end of the bus filter capacitor C0 and a first input end of the load module, and a second output end of the rectification voltage regulation module and a second end of the bus filter capacitor C0 are respectively connected with a second input end of the load module; the residual electricity recycling circuit comprises a controller, a residual electricity recycling storage circuit, a residual electricity recycling storage control circuit and a residual electricity cyclic utilization control circuit.

The present disclosure relates to an inverter operating at a high switching frequency and a method for operating an inverter. A motor controller performing a current regulator and a modulation routine in separate update intervals provides an improved fundamental voltage waveform to a motor controlled by the motor controller. The current regulator is performed at a first periodic update rate and the modulation routine is performed at a second periodic update rate, where the frequency at which the modulation routine is performed is at least twice the frequency at which the current regulator is performed. Performing the current regulator and the modulation routine at different frequencies results in the current regulator generating a single voltage reference signal over multiple cycles of the modulation routine. To reduce voltage ripple caused by decoupling the performance of the current regulator and the modulation routine, the motor controller extrapolates the voltage reference generated by the current regulator as multiple voltage reference signals, where a unique voltage reference signal is provided for each cycle of the modulation routine.

The application relates to an alternating-current auxiliary converter suitable for an internal combustion engine vehicle, which is connected with a permanent magnet generator through a cable and supplies power for the permanent magnet generator, the permanent magnet generator is connected with a diesel engine, the alternating-current auxiliary converter comprises an AC / DC rectifier, one end of the AC / DC rectifier is connected with the permanent magnet generator, the other end is connected with an ultra-wideband DC / DC voltage stabilizing converter, the other end of the DC / DC voltage stabilizing converter is output to a plurality of DC / AC inverters through a direct-current bus, and the DC / AC inverters are connected with corresponding devices. The alternating-current auxiliary converter has the remarkable characteristics of small overall size, wide alternating-current input range, low-voltage control and multi-path high-voltage output, solves the problem of insufficient space for electrical and mechanical layout, and the size of each system component is simplified on the basis of meeting the functional design.

A system (100) and method involve monitoring power quality events (144) using a variable speed drive (VSD) (102) that is electrically connected to an electrical supply grid (104) and a motor (106). The system and method include sampling measurements of a DC bus voltage (126) with the VSD (102), obtaining a data batch (118) of the sampled measurements, calculating a set of descriptive features (120) of the batch (118) with the VSD (102), and determining whether at least one descriptive feature (120) exceeds a predetermined threshold value. The VSD (102) sends the set of descriptive features (120) and data batch (118) to the cloud environment (114) for classifying one or more power quality events (144) using a machine learning model (140).

The invention relates to a frequency converter control method, a frequency converter, a readable storage medium and a program product. The method comprises the following steps: acquiring a power supply phase current under an alpha-beta coordinate system; determining a power supply phase voltage according to the power supply phase current; acquiring a reference voltage and a bus voltage of the output end of the rectification inverter; performing voltage loop control according to the reference voltage and the bus voltage to obtain voltage loop current; performing power control according to the voltage loop current, the power supply phase voltage and the power supply voltage, and determining a reference phase current; the power supply voltage is determined according to the power supply phase voltage; performing current loop control according to the reference phase current and the power supply phase current to obtain a target phase voltage; the target phase voltage is used for adjusting the voltage output by the rectification inverter. By adopting the method, the voltage control is accurate.

The utility model discloses a frequency converter with a protection function, and belongs to the technical field of frequency converters. Comprising a frequency converter shell, and mounting grooves are formed in the two sides of the frequency converter shell; the protection plate is slidably arranged on the outer side of the frequency converter shell; the limiting plates are fixedly arranged on the inner sides of the corresponding mounting grooves; wherein the outer side of the frequency converter shell is provided with a display screen, the protection plate is provided with a transparent plate corresponding to the display screen, and a magnet B is embedded in the inner side of the limiting plate. According to the frequency converter, the problems that in the prior art, for some frequency converters with display screens, the display screens of the frequency converters can be shielded when the frequency converters are protected through protection assemblies, and when information on the display screens needs to be observed, a protection shell needs to be opened, and a user cannot observe the display screens conveniently are effectively solved; therefore, the frequency converter is protected and the display screen of the frequency converter is convenient to observe.

The invention belongs to the field of dielectric loss testing, and provides a high-voltage anti-interference multifunctional dielectric loss tester and an operation method thereof.The high-voltage anti-interference multifunctional dielectric loss tester comprises an integrated core function module, and specifically comprises the following components: a measuring module which adopts a high-precision digital signal processing technology and a frequency conversion measuring circuit; the input module is provided with a multi-channel input interface, supports positive wiring, negative wiring, low-voltage magnetic field, high-voltage magnetic field and CVT self-excitation wiring modes, and is compatible with a built-in standard capacitor and an external high-voltage source; and an adjustable high voltage source is arranged in the power supply module. According to the power supply module, the multi-stage boost inverter topology is adopted, digital closed-loop feedback control is combined, through the IGBT switch tube and the high-voltage-resistance boost transformer, 10-180 kV wide-range voltage output is achieved, the voltage steady-state fluctuation is smaller than or equal to + / -0.5%, the testing requirement of ultrahigh-voltage equipment is met, three modes of positive wiring, negative wiring and a CVT self-excitation method are supported, and safety and accuracy are ensured.

This invention relates to the field of power distribution technology, and provides a power supply for an ozone generator, including a high-voltage power generation device and a control device. The high-voltage power generation device converts the three-phase AC power supplied by the power grid into double-peak high-voltage electricity, and transmits the generated double-peak high-voltage electricity to the discharge unit of the ozone generator. The control device is connected to the high-voltage power generation device and is used to detect and control the operation of the high-voltage power generation device, thereby realizing flexible adjustment of the power output and achieving the purpose of saving energy. At the same time, it adopts diode uncontrolled rectification technology, which has a high power factor of over 92%, effectively suppressing high-order harmonics generated by the power supply and preventing pollution to the power grid.

Power converter system (50) comprising: at least one power converter device (10) with a converter (2a) for converting alternating current power into direct current power, a first voltage sensor (5) for obtaining a direct current voltage generated on a direct current side of the converter, and a control unit (3) for controlling an operating state of the converter; and a voltage transformer (1) with a primary winding (1a) connected to an alternating current power supply, at least one secondary winding (1b), and a tertiary winding (1c) connected to a second voltage sensor (6), wherein the at least one secondary winding is connected to the at least one power converter device in a one-to-one ratio, wherein the control unit features: a phase calculation unit (30) for calculating a reference phase from a value obtained by the second voltage sensor; an active current command value calculation unit (321, 322) for calculating an active current command value on the basis of a deviation of a DC voltage command value from the DC voltage obtained by the first voltage sensor; a first reactive current command value calculation unit (324) for receiving the active current command value and a first coefficient as a proportionality coefficient, wherein the first coefficient is determined by coupled inductances of the voltage transformer and a received voltage of the voltage transformer, and for calculating a first reactive current command value proportional to a square of the active current command value, by using the first coefficient; and a voltage command value calculation unit (34; 35) for calculating an AC voltage command value based on the reference phase, the active current command value and the first reactive current command value.

The application discloses a topology structure and a control method of a bipolar composite offshore converter station, belongs to the technical field of offshore power transmission and distribution, and aims at solving the problems of large volume, complex structure and poor system reliability of the existing offshore wind power. The bipolar composite offshore converter station comprises a positive pole and a negative pole; the positive pole adopts a half-bridge modular multilevel converter topology structure, the negative pole adopts a diode rectifier topology structure, the two topology structures are connected in parallel at an alternating current side and are connected in series at a direct current side, and a direct current connection point is used as a grounding pole to form a symmetric bipolar structure. The topology structure of a shore converter station comprises: the positive pole and the negative pole both adopt a half-bridge modular multilevel converter topology structure. The control method comprises the following steps: when a direct current of the grounding pole increases from zero, an alternating current voltage rated value of the offshore converter station is added with a fine adjustment amount, the added value is used as a given value of a d-axis voltage ring of a wind turbine, the direct current of the grounding pole is kept as zero, power balance control of the positive pole and the negative pole is realized, and the application is used for the offshore converter station.

According to the auxiliary power supply for the protection device in the 380V power distribution system, a special auxiliary power supply module is additionally arranged on a typical wiring diagram of an original 380V motor, the input end is connected with a local three-phase alternating-current power supply and outputs direct-current 220V or alternating-current 220V, and when any two-phase alternating-current power supply on the alternating-current side is interrupted, the stable direct-current 220V or alternating-current 220V power supply can still be output. In order to thoroughly eliminate the traditional 380V alternating current power distribution system, the auxiliary power supply device is connected to the original 380V alternating current power distribution system, so that the motor protector or the comprehensive protection device can still supply power normally when the 380V alternating current power distribution system is subjected to single-phase grounding or two-phase interphase grounding short circuit.

Method for monitoring the operation of a frequency converter (1) designed to control an electric motor in the form of a synchronous motor (2), the method comprising the steps: - Generating phase voltages (u1, u2, u3) for corresponding phase strands (2.1, 2.2, 2.3) of the electric motor (2), - Determining a voltage rotating field, - Measuring the phase currents that are forming (i1, i2, i3), - Determining a current rotation field as a function of the measured phase currents (i1, i2, i3), and - Calculating a phase difference between the voltage rotating field and the current rotating field and / or calculating a frequency difference between the frequency of the voltage rotating field and the frequency of the current rotating field, - wherein the phase voltages (u1, u2, u3) are generated such that, with fault-free operation of the frequency converter (1), the magnitude of a current vector (I) corresponding to the current rotating field does not fall below a minimum value (Imin), characterized in that - a fault condition of a gate signal generation, the electric motor (2) and / or a current measurement is determined when the phase difference exceeds a phase difference threshold and / or when the frequency difference exceeds a frequency difference threshold.

This invention relates to a method for locating ground faults in an IT system. A method for locating ground faults in an IT system (1) having a power transmission network (5), rotating electric machines (7, 8), and converters (9, 10), wherein the converters (9, 10) have an inverter (17) connected to the electric machines (7, 8). In this method, the common-mode voltage characteristics of the common-mode voltage of the converters (9, 10) or the power transmission network (5) are detected, and the common-mode voltage characteristics are compared with the output voltage characteristics of the output voltage of the inverter (17). In the event of a ground fault in the IT system (1), based on the comparison between the common-mode voltage characteristics and the output voltage characteristics, it is inferred whether a machine area (21, 22) downstream of the converters (9, 10) in the IT system (1) is the cause of the ground fault, the machine area including the electric machines (7, 8) and the connecting lines (19, 20) between the electric machines (7, 8) and the converters (9, 10).

The embodiment of the utility model discloses an integrated power supply system and an integrated power supply table, the integrated power supply system comprises a power supply module, at least one first direct current output assembly and at least one first alternating current output assembly, and the power supply module comprises a first rectifier module. The first direct current output assembly comprises a first direct current transformation module electrically connected with the first rectification module and at least one direct current output interface electrically connected with the first direct current transformation module; the first AC output assembly comprises a first inversion module electrically connected with the first rectification module, and at least one AC output interface electrically connected with the first inversion module. The direct current is transmitted in the wiring line between the power supply module and the first direct current output assembly, and the direct current is transmitted in the wiring line between the power supply module and the first alternating current output assembly, so that a user is prevented from being in contact with the wiring transmission of the alternating current when working on the desktop, and the power utilization safety is improved.

The utility model discloses a converter structure suitable for a double-machine-head wind generating set, which comprises a first machine-side filter, a second machine-side filter, a machine-side nine-switch converter, a direct-current loop, a grid-side converter and a grid-side filter, the input end of the first machine-side filter is electrically connected with a first generator of the set, and the output end of the second machine-side filter is electrically connected with a second generator of the set. The output end of the first machine-side filter is electrically connected with the input end of an upper bridge arm of the machine-side nine-switch converter, the input end of the second machine-side filter is electrically connected with a second generator of the unit, the output end of the second machine-side filter is electrically connected with the input end of a lower bridge arm of the machine-side nine-switch converter, and the input end of the direct-current loop is electrically connected with the output end of the machine-side nine-switch converter. The output end of the direct-current loop is electrically connected with the input end of a grid-side converter, the output end of the grid-side converter is electrically connected with the input end of a grid-side filter, and the output end of the grid-side filter is connected to a power grid through a transformer. The utility model can effectively reduce the construction cost of the wind generating set.

The invention provides a rectification inversion module and a frequency conversion cabinet. The rectification inversion module comprises an inversion module which comprises an inversion module body and a first frame body, and the inversion module body is arranged on the first frame body and used for converting alternating current into direct current; the rectifying module comprises a rectifying module and a second frame body, the rectifying module is arranged on the second frame body and used for converting the direct current into the alternating current, and the second frame body and the first frame body are arranged side by side in the first direction and detachably connected with each other. In this way, the structure compactness and the disassembly, assembly and maintenance convenience of the frequency conversion cabinet can be improved.

The examples described here provide a circuit that includes a power electronics converter located in a vehicle, wherein the power electronics converter is designed to receive alternating current (AC) electrical power from an AC mains source and to supply AC electrical power to an AC load outside the vehicle. The power electronics converter includes an AC / AC converter comprising a rectifier and an inverter, the rectifier being electrically connected to the inverter via a direct current (DC) connection. The circuit further includes a vehicle-side charging module that is electrically connected to the power electronics converter and a battery located in the vehicle.The power electronics converter provides vehicle-to-load functionality by supplying AC electrical power to the AC load as a 120 Vac output and / or a 240 Vac output.