34results about How to "Reduce current spikes" patented technology

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 discloses an intelligent IGBT constant current drive device, which comprises an isolated DC-DC module, a PLD digital control module, a DAC digital-to-analog conversion module, a controlled constant current source, a voltage comparison logic circuit, a gate-level current acquisition circuit and Current comparison logic circuit. The driving power and driving signal of the primary side control part provide isolated driving power and driving signal for the secondary side through the isolated DC-DC module, and the alarm signal of the secondary side provides an isolated alarm signal for the primary side through the isolated DC-DC module; The output terminals of the driving signal, the voltage comparison logic circuit and the current comparison logic circuit are connected to the input terminal of the PLD digital signal, the output of the PLD is connected to the input of the DAC digital-to-analog conversion module, and the output of the DAC digital-to-analog conversion module and the subtraction circuit is connected to the controlled constant The input of the current source is connected, and the output of the controlled constant current source is connected to the gate level of the IGBT through the driving resistor Rg. The device of the present invention takes PLD digital control as the core, and can adjust the output of the control loop according to the difference in parameters of different types of IGBTs, so as to realize the optimal control of different series and types of IGBTs.

A multi-stage soft charge control method and system for a multi-level DC solid-state transformer, which relates to the field of power electronics technology, and solves the problem of how to reduce the current peaks of the AC side and the DC side when the modular multi-level DC solid-state transformer is started; the described The multi-stage soft charging control method includes: uncontrolled charging of the sub-module of the primary side MMC; using peak current to control the soft charging of the sub-module of the primary side MMC; using phase-shift modulation to control the soft charging of the sub-module of the secondary side MMC; the control System, including input source, output source, primary side MMC, secondary side MMC, current limiting resistor R d , the current limit switch S d , high-frequency transformer; realizes the fast and stable charging of the sub-module capacitor of the modular multi-level DC solid-state transformer, reduces the current peak of the AC side and the DC side when the transformer is started, and protects the power devices and high voltage in the sub-module The frequency transformer increases the service life of the capacitor and is beneficial to the safe operation of the system.

A method for managing a load supplied by a converter that is itself supplied by a battery, and corresponding system. A method and corresponding system for managing a load supplied by a converter that is itself supplied by a battery comprising modules that can be switched, a capacitor being disposed between the battery and the converter. The method comprises: detecting a switching command (E01), if a switching command is detected, the converter supplies a low power to the load (E02), carrying out the switching (E03), if the switching is carried out, the converter supplies a normal power to the load (E04). The invention is applicable to the management of power trains of motor vehicles having electric or hybrid traction.

The invention discloses a low-output-voltage-ripple discontinuous-mode flyback power factor correction converter. The converter comprises a Flyback converter main power circuit, an output voltage feedback control circuit, a control drive circuit, and an input voltage feedforward circuit. The input voltage feedforward circuit comprises an input voltage sampling following circuit, an input voltage peak sampling circuit, a subtraction circuit, and a multiplying circuit. The output end of the input voltage sampling following circuit is connected with one input end of the subtraction circuit, and the output end of the input voltage peak sampling circuit is connected with the other input end of the subtraction circuit and one input end of the multiplying circuit. The output end of the subtraction circuit is connected with the other input end of the multiplying circuit. According to the invention, the input voltage feedforward circuit is introduced, thereby enabling the duty ratio of a switching tube to change regularly in a period of a working frequency, and finally achieving the output voltage ripple.

The invention discloses a control method for effectively reducing the voltage peak and circulating current of a switching tube of a bidirectional forward converter, mainly aimed at the working condition that the bidirectional forward converter transmits power from the low-voltage side to the high-voltage side, and the low-voltage side switching tubes QSR1 and QSR2 are low Level complementary switching control, there is a high-level common conduction time, and the high-voltage side switch Q is always turned off; Qg, Qg_SR1 and Qg_SR2 correspond to the drive control signals of the switch Q, QSR1 and QSR2, and the high level corresponds to the switch. Turn on, the low level corresponds to the switch off, within a switching cycle, the high level time of Qg_SR1 is less than 1 / 2 switching cycle, the high level time of Qg_SR2 is greater than 1 / 2 switching cycle, Qg keeps low level . The invention is simple to implement, can effectively reduce the switch tube voltage, current peak and circulating current of the bidirectional forward converter, improve the safety, efficiency and power density of the converter, and increase the transmission power.

The invention discloses a control method of a single-phase brushless motor. The brushless motor using this control method is used in an electric tool, and the electric tool includes a position sensor, a drive circuit and a controller; the control method includes: when the position signal output by the position sensor changes, the controller After closing the currently output control signal and lagging the non-conduction angle T, the controller triggers to output a target control signal to the drive circuit, and the drive circuit drives the single-phase brushless motor according to the target control signal. The control method uses the change of the position signal output by the position sensor as an instruction, the controller turns off the current output control signal, and triggers the target control signal to the drive circuit after the non-conduction angle T to drive the single-phase brushless motor to reduce current spikes in single-phase brushless motors. The overall performance of the single-phase brushless motor is improved, and the size of the electric tool motor and the corresponding control board are reduced.