47results about How to "Reduce the rate of voltage change" patented technology

The invention discloses a source electrode drive circuit and a controlling method thereof. The source electrode drive circuit comprises controlling transistors, a power supply capacitor and a current feed diode, wherein the controlling transistor are connected between the second end of a main switch pipe and the ground; the two ends of the power supply capacitor receive approximately constant bias voltage; the cathode of the current feed diode is connected to the control end of the main switch pipe; the anode of the current feed diode is connected with the second end of the main switch pipe; the controlling transistors are conducted and switched out periodically to enable the main switch pipe to be conducted and switched out correspondingly along the controlling transistors; the conducting time quantum of the main switch pipe comprises a first stage from starting in switching out state to completely conducting, and a second stage of being in completely conducting state; in the first stage, the controlling transistors provide approximately constant starting current. The source electrode drive circuit prolongs the conducting time of the main switch pipe, so as to restrain EMI greatly; meanwhile, time delay in switching out process of the main switch pipe is avoided, so as to reduce additional power consumption.

The invention discloses a current-sharing circuit for high-power parallel IGBT modules. The circuit comprises a controller and a plurality of current-sharing control branches connected in parallel, wherein each current-sharing control branch comprises a first current detection circuit, a second current detection circuit, a first drive circuit, a second drive circuit and a transformer T; the firstcurrent detection circuits and the second current detection circuits are used for detecting output current of the first IGB module and the second IGBT module separately to obtain two paths of detection current transmitted to the controller; the controller generates two paths of control signals according to the magnitudes of the two paths of detection current; the two paths of control signals are driven through the first drive circuits and the second drive circuits separately and then transmitted to the transformers T; and the transformers T synchronously output the two paths of control signalsto grids of the first IGBT module and the second IGBT module. According to the current-sharing circuit, the problem of imbalance of static current-sharing in a conducting state and dynamic current-sharing in a switching state is solved while the cost of a control driver is not greatly increased.

The invention relates to the technical filed of the multi-power-level high-voltage transducer, in particular to a five power-level transducer and the control method thereof. The five power-level of the invention is formed by connecting a high-voltage rectifier circuit, a high-voltage capacitor filter circuit, a voltage balancing circuit, and an inverting circuit in turn. The invention is characterized in that the inverting circuit adopts one or two apparatus / apparatuses in the IGBT and the IGCT to form an inverter, adopts a diode clamping five-power-level structure and three inverters with uniform bridge arms. The invention can provide higher resolution and can obtain better harmonic characteristic for the low-voltage area of a signal, better output characteristic and high-voltage high-power output for the high-voltage area of the signal; in addition, the invention has the advantages of easy control, and being safe and reliable.

The invention discloses a driving circuit of a silicon-carbide semiconductor field-effect transistor. The driving circuit comprises a PWM control circuit, a driving signal amplifying circuit, an opening circuit, a turning-off circuit, a gate current-increasing circuit and a voltage change rate control circuit. With the gate current-increasing circuit, the driving current is increased during the opening process of the SiC MOSFET and the rising of the gate-source voltage of the SiC MOSFET is accelerated, so that the opening speed of the SiC MOSFET is increased. With the voltage change rate control circuit, the Miller capacitance between the SiC MOSFET drain and gate is enhanced and the SiC MOSFET drain-source voltage change rate is reduced, so that the current spike during opening of the SiCMOSFET is reduced. After the SiC MOSFET drain-source voltage does not change, a voltage control switch is turned off to avoid the SiC MOSFET false conduction caused by the crosstalk, so that the safeoperation of the SiC MOSFET is ensured.

The invention relates to a drive circuit for preventing the oscillation of grid drive signals. The drive circuit is characterized by comprising a buffer circuit, an amplitude limiting circuit and a rapid discharge circuit, wherein the buffer circuit receives and processes a drive signal PWM (Pulse Width Modulation) and then outputs the signal to the amplitude limiting circuit; the amplitude limiting circuit processes the received signal and then respectively outputs the signal to the grid of an MOS (Metal Oxide Semiconductor) transistor and the rapid discharge circuit; and the rapid discharge circuit also receives the drive signal PWM. The drive circuit has the advantages of lowering the voltage change rate of the MOS transistor, decreasing the open surge in the opening process, reducing the impact and damage to the MOS transistor, improving the EMC (Electro Magnetic Compatibility) property of the whole switch power supply, decreasing the turnoff loss, effectively avoiding the abnormal oscillation of drive signals, protecting normal working states of the MOS transistor and the circuit, and the like.

The invention relates to the technical field of power electronics and discloses a unified power flow controller in the modular structure. A structurally modified modular multilevel converter is organically combined with a unified power flow controller so that direct-current voltage of the unified power flow controller is halved and the unified power flow controller is imparted with individual phase control capacity; a power electronic bypass switch on the serial side of the unified power flow controller provides higher safety, and the requirement on converter switching devices is lower. In addition, the unified power flow controller has the advantages of compact structure of the modular multilevel converter, flexibility in voltage and power level change, low switch frequency, low loss, low content of output waveform harmonic and the like.

The invention discloses a low-interference food processing machine, comprising a control circuit. The control circuit comprises a load for food processing, a load circuit for driving the load to work and a control chip. The load circuit comprises a switch which is a thyristor. The control chip controls the thyristor in a wave leaking way. The control chip controls the thyristor with a trigger pulse. A rising edge of the trigger pulse is at a zero-crossing point of power supply voltage. The trigger pulse maintains at the point of a minimum rate of change of the power supply voltage. The control chip can remove the trigger pulse at the minimum rate of change of the power supply voltage by adjusting the maintaining time of the thyristor trigger pulse, the interference brought by the thyristor trigger can thus be reduced, and the problem of magnetic interference of the resistive load is solved.

The invention discloses a double welding torch direct-current arc welding and power generation machine, which comprises a machine base, a rotating shaft, an electric brush device, a sliding ring as well as a main generator and a vice generator which have same number of poles, wherein the main generator has a first excitation regulation circuit with closed-loop automatic adjustment; and the vice generator has a second excitation regulation circuit with open-loop regulation. When the welding current of single torch is smaller than 50 percent of Ihm, double torches can be used simultaneously, thus improving the usage rate of welding machines and saving energy sources. When the current of the electric welding machines is greater than 50 percent of Ihm, output terminals of the two electric welding machines can be parallelly used.

The invention discloses a switch assembly. The switch assembly comprises a unit chain which is connected in series with an inductor. The unit chain comprises a plurality of half-bridge active clamping units which are successively connected in series. Each half-bridge active clamping unit has a conducting state and a clamping state. When all half-bridge active clamping units are in the conducting state, the switch assembly is closed. When all half-bridge active clamping units are in the clamping state, the switch assembly is open. By clamping or turning on the half-bridge active clamping units one by one, the voltage across both ends of the switch assembly rise or fall step-by-step, which reduces the device requirement of the switch assembly. The invention discloses a modular multi-level DC / DC converter. The switch assembly replaces a single-power device in a conventional DC / DC converter to acquire the modular multi-level DC / DC converter. The device requirement in the modular multi-level DC / DC converter is reduced. The invention discloses a modulation method and a clamping capacitor voltage balancing method.

The invention relates to the technical field of a multiple level high voltage transducer, in particular to a seven level high voltage transducer which is formed by mixing couplet components and a controlling method. The seven level high voltage transducer of the invention comprises a high voltage rectification circuit, a high voltage capacitance filtering circuit, an equalizer circuit and an inversing circuit which are connected in turn, which is characterized in that the inversing circuit is formed into an inverter through adopting one or two components of IGB and IGCT, adopting the inverter with the structure of diode clamping seven level structure, and three bridge arms of the inverter are same. The transducer of the invention can provide a higher differentiate ratio to a low voltage area of signals, obtain a better harmonious wave characteristic, and the transducer can obtain a better output characteristic to the high voltage area, also obtain a high voltage large power output, and simultaneously the transducer has simple control, safety and reliability.

The invention discloses an indirect matrix transformation type multi-phase multi-level permanent magnet motor system. The indirect matrix transformation type multi-phase multi-level permanent magnet motor system includes a double-stator multi-phase composite permanent magnet synchronous motor, wherein two independent five-phase three-level inverters supplies power for stator winding ports of the motor respectively; an independent controllable rectifier supplies power for each five-phase three-level inverter; the two controllable rectifiers can share one set of LC filter at the power grid side; the LC filter includes a three-phase grid-connected inductor and a three-phase filter capacitor which is connected with the three-phase grid-connected inductor in parallel; and the first five-phase three-level inverter and the second five-phase three-level inverter are respectively connected with the two stator winding ports of the double-stator multi-phase composite permanent magnet synchronous motor. The invention also discloses a control method of the indirect matrix transformation type multi-phase multi-level permanent magnet motor system. The indirect matrix transformation type multi-phase multi-level permanent magnet motor system and the control method thereof can significantly improve reliability, power density, torque smoothness and operation efficiency of the motor driving system, and can lay the foundation of solving the technical difficulty that a high capacity motor traction driving system requires compact designs, reliable operation and energy-efficient aspects.

The invention discloses an active discharge system of a motor controller. The active discharge system comprises a control module, a plurality of driving modules, an upper bridge driving power supply module and a lower bridge driving power supply module, wherein the driving modules are connected with the control module and semiconductor switches in corresponding bridge arms; the upper bridge driving power supply module is connected with the driving modules corresponding to all upper bridge arms; the lower bridge driving power supply module is connected with the control module and the driving modules corresponding to all lower bridge arms; and when the control module needs to perform active discharge, the driving modules corresponding to the upper bridge arms are triggered to drive the semiconductor switches in the upper bridge arms to enter straight-through states, the lower bridge driving power supply module is triggered to lower output voltages output to the driving modules corresponding to the lower bridge arms at the same time in order that the semiconductor switches in the lower bridge arms enter a linear region, and the driving modules corresponding to the lower bridge arms are triggered to drive the semiconductor switches in corresponding lower bridge arms to enter short-term on-off states. Through adoption of the active discharge system, cost is lowered, and voltage and current change rates of the semiconductor switches of the lower bridge arms in an active discharge process can be reduced.

The invention provides a filter, a SiC traction converter adopting the filter and a parameter design method and a device of the SiC traction converter. The filter comprises a common-mode filter circuit used for reducing common-mode interference current and common-mode voltage of a load end of the filter, and an input end of the common-mode filter circuit is an input end of the filter; a differential mode filter circuit is used for reducing the voltage change rate and the peak voltage amplitude of the load end of the filter, the input end of the differential mode filter circuit is connected with the output end of the common mode filter circuit, and the output end of the differential mode filter circuit is the output end of the filter. the output end of the filter is connected with a load through a connecting line.

The present invention discloses a voltage sharing protection control circuit of series IGBT, and the structural feature is the setup of the voltage change rate control circuit and the terminal voltage clamp control circuit, wherein the voltage change rate control circuit is composed by a one-way conducting diode D2, a charge-discharge capacitance C1 and a resistance R2; during switch off time of the IGBT, the conducting diode D2 and the capacitance C1 in charged state constitute IGBT external capacitance parallel to CG end of the IGBT; during conducting time of the IGBT, the capacitance C1 takes resistance R2 as discharge path; the terminal voltage clamp circuit is composed by a triode T1 and T2, the clamp state is that DC passes through triode T2, diode D3 and charge grid capacitance of the IGBT. The present invention constitutes control circuit with simple analog elements, realizes IGBT switch voltage waveform similar to standard curve, and realizes different voltage change rate in different stages of the switch process.

The invention provides a modulation method for phase shifts among bridge arms of an isolated modular multi-level DC-DC converter. According to the method, phase shift angles are introduced among various bridge arms of the modular multi-level DC-DC converter to generate a quasi two-level waveform of which the number of edge steps is 4N+1 on an AC side. The quasi two-level waveform with a greater number of steps is generated on the AC side, so that the voltage change ratio of the AC side is further reduced, electromagnetic interference is reduced, and meanwhile, the higher harmonic content of AC voltage and insulation impact on a transformer are relieved.

The invention discloses a three-level DC conversion circuit with controllable neutral point voltage and a control method thereof. The three-level DC conversion circuit of the present invention comprises a DC power supply, a first capacitor, a second capacitor, a first set of DC chopper circuit and a second set of DC chopper circuit; the first set of DC chopper circuit and the second set of DC chopper circuit are connected in parallel by three points of a positive voltage terminal, a negative voltage terminal and an intermediate voltage terminal, and an output positive terminal of the first setof DC chopper circuit and an output negative terminal of the second set of DC chopper circuit are connected in series with a load; and each of the first set of DC chopper circuit and the second set of DC chopper circuit comprises a plurality of switch tubes and a plurality of diodes. The three-level DC conversion circuit of the invention can constitute a plurality of control modes by controllingconduction of the switch tubes, thereby combining a plurality of timing sequence modes, so that four-quadrant voltage control operation of the load condition can be realized, and the purpose of controlling balance of the neutral point voltage of the three-level circuit can be achieved through mode switch.

The invention provides a middle-high voltage charging system control method based on a series digital voltage stabilizer, and belongs to the field of middle-high voltage electric vehicle charging stations. An output voltage of the series digital voltage stabilizer is controlled to be matched with a high-voltage cascade H-bridge module to form multi-level alternating current modulation voltage, theswitching frequency of the high-voltage cascaded H-bridge module is reduced, meanwhile, the size and inductance loss of a grid-side filter inductor are effectively reduced, and in cooperation with voltage stabilization control of a rear-stage DC / DC isolation stage of a digital series digital voltage stabilizer, voltage stabilization and balance of all modules of the system are guaranteed, so thesystem stably operates, and meanwhile system operation efficiency is improved.

A light unit cascade multi-level power converter comprises: an outputting transformer, a light unit, a central control system and a pump electrical source. The light unit comprises an unit power circuit, an unit electric source and an unit control system. The unit power circuit is connected to a group of sub-winding group of the multi-output transformer by three ends to output by two ends y1 and y2, and is connected to other light unit phase with the same phase. The unit power circuit has five structures, each structure has a plurality of structure style due to using different power devices. An electrical waveform at the light unit outputting side closes to sine. A pump power supply provides power for the central control system, the unit control system of the light unit and a driving power of the power device. The pump power supply outputs a high-frequency square wave alternating current which crosses each light unit and the control system through a high-voltage insulation cable, each light unit and the control system obtain a multi-way isolated low voltage direct current power supply by coupling magnetic loops insulative each other.

The invention discloses an indirect matrix transformation type multi-phase multi-level permanent magnet motor system. The indirect matrix transformation type multi-phase multi-level permanent magnet motor system includes a double-stator multi-phase composite permanent magnet synchronous motor, wherein two independent five-phase three-level inverters supplies power for stator winding ports of the motor respectively; an independent controllable rectifier supplies power for each five-phase three-level inverter; the two controllable rectifiers can share one set of LC filter at the power grid side; the LC filter includes a three-phase grid-connected inductor and a three-phase filter capacitor which is connected with the three-phase grid-connected inductor in parallel; and the first five-phase three-level inverter and the second five-phase three-level inverter are respectively connected with the two stator winding ports of the double-stator multi-phase composite permanent magnet synchronous motor. The invention also discloses a control method of the indirect matrix transformation type multi-phase multi-level permanent magnet motor system. The indirect matrix transformation type multi-phase multi-level permanent magnet motor system and the control method thereof can significantly improve reliability, power density, torque smoothness and operation efficiency of the motor driving system, and can lay the foundation of solving the technical difficulty that a high capacity motor traction driving system requires compact designs, reliable operation and energy-efficient aspects.

The invention discloses a control system and method of a high-voltage inverter based on a DTC algorithm. The method includes the steps that S1, three-phase output voltages and currents output by the high-voltage inverter are obtained, and the stator flux linkage of a motor is calculated; S2, electromagnetic torque is calculated according to the stator flux linkage of the motor and stator currents; S3, closed-loop PID calculation is performed on speed setting and speed feedback of the motor to generate a torque signal; S4, the flux linkage sector, in a stationary coordinate system, of the stator flux linkage is obtained through calculation according to the stator flux linkage of the motor; S5, a switching vector is calculated according to output of a flux linkage hysteresis comparator, output of a torque hysteresis comparator and the flux linkage sector; S6, phase shifting is performed on power units of the high-voltage inverter according to the switching vector based on the DTC algorithm, so that corresponding PWM signals are generated. The electromagnetic torque can be rapidly and accurately controlled, and quick responses to sudden load increasing and decreasing are achieved.

The invention provides a method for forming a lithium ion battery with a mixed electrode. The active material of the mixed electrode includes lithium nickel cobalt manganate and lithium iron phosphate. The lithium nickel cobalt manganate is LiNi0.6Co0.1Mn0.3O2. The lithium iron phosphate is LiMg0.02Fe0.98PO4. The mass ratio of the lithium nickel cobalt manganate to the lithium iron phosphate is 75:25 to 80:20. The method includes performing charge-discharge cycles in a range of 3.55 to 3.65V and performing charge-discharge cycles in a range of 3.70 to 3.90V. The formation method of the presentinvention can fully activate the electrochemical activity of the active material of the mixed electrode, and improve the charge-discharge efficiency and durability of the electrode.

The invention relates to a drive circuit for inhibiting SiC MOSFET peak and crosstalk, which is connected in a SiC MOSFET drive circuit, and comprises an upper bridge arm and a lower bridge arm, a voltage totem pole structure circuit is connected between a first positive power supply and a first negative power supply of the lower bridge arm, and the first positive power supply and the first negative power supply of the lower bridge arm are connected with the voltage totem pole structure circuit. The output end of the voltage totem-pole structure circuit is connected with the input ends of the driving resistance circuit and the negative-voltage turn-off voltage pull-up circuit, the output end of the driving resistance circuit is connected with the input ends of the current extraction circuit and the current injection circuit, and the output end of the negative-voltage turn-off voltage pull-up circuit is connected with the grid electrode of the lower bridge arm SiC MOSFET; the upper bridge arm and the lower bridge arm are symmetrically arranged except for a non-negative-voltage turn-off voltage pull-up circuit. According to the invention, the performance advantages of high switching speed and low loss of the SiC MOSFET can be brought into full play, and the additional loss caused by bridge arm crosstalk negative voltage turn-off is suppressed while the switching-on current and the switching-off voltage peak are suppressed.

The invention relates to a negative voltage protection circuit. On one hand, a drain voltage control module disconnects a conductive path between a drain power supply and a drain of a power amplifier tube according to a first voltage, a second voltage and a drain switching signal, so that timely disconnection of the drain voltage can be realized through the first voltage, the second voltage and the drain switching signal; and on the other hand, when the received second voltage is changed into 0V, a voltage buffer module reduces the voltage change rate of an output sixth voltage, and finally, the time required for the drain electrode of the power amplifier tube to be powered off and the drain voltage to be reduced to be 0 is far shorter than the time required for the sixth voltage of the grid electrode of the power amplifier tube to be reduced to be 0, namely, when the drain electrode of the power amplifier tube is powered off and the drain voltage becomes 0, the sixth voltage only changes by a small amount, and the grid voltage is always under the safe negative voltage protection, so that the protection of the power amplifier tube is realized.

The invention discloses a three-port DC-DC converter topological structure and a control method thereof. The three-port DC-DC converter topological structure comprises an input port and two output ports, the structure of one input port is an MMC circuit and is used for bearing high voltage of a medium-voltage direct-current power grid; the MMC circuit has two phases, each phase is composed of an upper bridge arm and a lower bridge arm, each bridge arm comprises n sub-modules with the same structure, and each sub-module adopts a half-bridge type sub-module topological structure; the two output ports are DAB circuits and comprise a first low-voltage side DC / AC full-bridge circuit and a second low-voltage side DC / AC full-bridge circuit; wherein the input port and the output ports are connected through the isolation transformer. According to the three-port DC-DC converter topological structure, energy transmission from an MVDC side to an LVDC side can be realized; the voltage change rate can be reduced, the impact of instantaneous voltage on the switch is reduced, and stable power transmission is realized; each-phase ring current is reduced, and power loss is reduced.

The invention discloses a converter for converting high-voltage direct current into alternating current in a high voltage direct current-light (HVDC-Light) system. The converter is characterized by comprising a direct current / direct current (DC / DC) input stage and a direct current / alternating current (DC / AC) inverting stage; the DC / DC input stage consists of a resonant soft switching converter; the secondary stage of a high-frequency transformer in the converter is provided with independent N*3 windings, the output voltage of each winding is subjected to rectification and capacitive energy storage, and N*3 mutually-isolated and equivalent independent direct current power supplies are formed; and the DC / AC inverting stage comprises N*3 power units, each power unit consists of a single-phase full-bridge inverter, the direct current input end of each power unit is connected to an independent direct current power supply, the alternating current output ends of N power units are sequentially connected in series to form an alternating current output phase of the converter, and three phases are connected into a three-phase alternating current output in a star-shaped (also called as Y-shaped) mode.

The invention discloses a three-level open source driver system, which relates to the field of electromechanical control and comprises a signal adapter plate, a three-level processing plate, a three-level driving plate, a three-level bus capacitor plate and an EMC (Electro Magnetic Compatibility) electromagnetic compatibility plate, the EMC electromagnetic compatibility board is used for reducing and suppressing electromagnetic interference generated by the three-level open source driver system; the signal adapter plate is used for collecting signals and sending the collected signals to the three-level processing plate. The three-level processing board is used for conditioning collected signals and comprises a first sampling signal conditioning module, a digital input module, a digital output module, a multi-path power supply module, an encoder collection module, a protection module and a fault reset module; the circuit has the advantages of small voltage change rate, large output capacity, small loss, low distortion factor, low output harmonic content, high topology withstand voltage, good quality of output voltage signals, perfect protection function and the like.

The invention discloses a driving circuit of a silicon-carbide semiconductor field-effect transistor. The driving circuit comprises a PWM control circuit, a driving signal amplifying circuit, an opening circuit, a turning-off circuit, a gate current-increasing circuit and a voltage change rate control circuit. With the gate current-increasing circuit, the driving current is increased during the opening process of the SiC MOSFET and the rising of the gate-source voltage of the SiC MOSFET is accelerated, so that the opening speed of the SiC MOSFET is increased. With the voltage change rate control circuit, the Miller capacitance between the SiC MOSFET drain and gate is enhanced and the SiC MOSFET drain-source voltage change rate is reduced, so that the current spike during opening of the SiCMOSFET is reduced. After the SiC MOSFET drain-source voltage does not change, a voltage control switch is turned off to avoid the SiC MOSFET false conduction caused by the crosstalk, so that the safeoperation of the SiC MOSFET is ensured.

The present invention provides a phase-shift modulation method between bridge arms of an isolated modular multi-level DC-DC converter. The method introduces a phase-shift angle between each bridge arm of the modular multi-level DC-DC converter to achieve The AC side generates a quasi-two-level waveform with a step number of edges of 4N+1. The invention generates quasi-two-level waveforms with more steps on the AC side, further reduces the voltage change rate on the AC side, reduces electromagnetic interference, and at the same time relieves the high-order harmonic content of the AC voltage and its insulation impact on the transformer.

Disclosed are a source driving circuit and a control method thereof. The source drive circuit includes: a control transistor, connected between the second terminal of the main switch tube and the ground; a power supply capacitor, the two ends of the power supply capacitor receive a substantially constant bias voltage; and a feed diode, the feed diode The cathode is connected to the control terminal of the main switch tube, and the anode is connected to the second terminal of the main switch tube, wherein the control transistor is periodically turned on and off, so that the main switch tube follows the control transistor and correspondingly conducts On and off, the conduction period of the main switch tube includes the first stage from the off state to the full conduction state and the second stage in the full conduction state, in the first stage, the The control transistor provides an approximately constant startup current. The source drive circuit prolongs the conduction time of the main switch tube, thereby advantageously suppressing EMI. At the same time, it also avoids the delay of the disconnection process of the main switch tube, thereby reducing the additional power consumption.

The present invention relates to a negative voltage protection circuit. On the one hand, the leakage voltage control module disconnects the conductive path between the drain power supply and the drain of the power amplifier tube according to the first voltage, the second voltage and the drain switch signal, so that through the first The first voltage, the second voltage and the drain switch signal can realize the timely disconnection of the drain voltage; on the other hand, when the received second voltage becomes 0V, the voltage buffer module reduces the voltage change of the output sixth voltage rate, and finally the drain of the power amplifier tube is powered off and the time required for the drain voltage drop to 0 is much shorter than the time required for the sixth voltage drop of the power amplifier tube grid to be 0, that is, the drain of the power amplifier tube is powered off to the drain During the period when the voltage becomes 0, the sixth voltage only changes by a small amount, and the grid voltage is always under the safe negative voltage protection, so as to realize the protection of the power amplifier tube.