34results about How to "Achieving Soft Shutdown" patented technology

The invention belongs to the technical field of electrical engineering and the automatization and relates to a direct current voltage reduction technology. The capacitance voltage division type direct current voltage reduction technology is that voltage division is performed on direct current on the high-voltage side through series capacitors, a switch is sequentially connected with two ends of one or more capacitors in the series capacitors, electric charges of the capacitors are transferred to an energy storage element at the output end, and output voltage on the low-voltage side can be controlled by regulating the on-off speed of the switch. The energy storage inductance of a direct current voltage reduction circuit can be decreased, and technical support is provided for miniaturization of a direct current voltage reduction device.

The invention discloses a boost type converter for realizing high-gain voltage multiplication by coupling inductors, comprising two switching tubes, two clamping diodes, a freewheel diode, an output diode, a clamping capacitor, a voltage-multiplying capacitor, an output capacitor and two coupling inductors respectively provided with two windings. The two coupling inductors are utilized to improve the gain of the converter and reduce the voltage stress of the switching tubes and the diodes in the converter, and the leakage inductance of the coupling inductors is utilized to realize the zero current turn-on of the switching tubes and the soft turn-off of the diodes. A clamping circuit consisting of the clamping diodes and the clamping capacitor absorbs a switching tube turn-off voltage spike caused by the leakage inductance and realizes the lossless transfer of energy. A voltage-multiplying circuit is utilized to further improve the gain of the converter and reduce the voltage stress of the switching tubes and the output diode, and staggered parallel connection is utilized to control and reduce ripple waves of input current.

The invention discloses a multi-stage grid voltage reduction SiC-MOSFET drive circuit, including a short-circuit detection circuit, a turn-off logic control circuit, a totem pole circuit, a first-stage grid voltage reduction circuit, and a second gate voltage reduction soft-off circuit The short-circuit detection circuit judges the short-circuit peak current to detect the real occurrence of a short-circuit fault, and the first-stage gate voltage reduction circuit reduces and maintains the SiC-MOSFET gate voltage to the maximum short-circuit withstand time, improving the short-circuit ride-through capability of the device; through the second-stage reduction The gate voltage circuit further reduces the gate voltage to achieve soft turn-off, thereby suppressing the turn-off voltage spike. The invention ensures that the SiC-MOSFET is safely turned off under short-circuit conditions, effectively increases its short-circuit withstand time, and improves the fault ride-through capability.

The invention discloses a Buck soft switching circuit for supercapacitor charging, comprising a Buck circuit composed of an input voltage source Vh, an output voltage source Vl, a main inductance Lm, a main switching tube S2, and a main diode D1, and the output voltage source Vl A first capacitor C1 is connected between the negative electrode and the collector of the main switching tube S2, a main diode D1 is connected in parallel between the two ends of the main inductance Lm and the output voltage source V1, the collector of the main switching tube S2 and the first auxiliary switching tube Sa2 Collector connection, resonant capacitor Cr is connected between the emitter of the main switching tube S2 and the emitter of the first auxiliary switching tube Sa2, and the emitter of the first auxiliary switching tube Sa2 is also connected with the collector of the second auxiliary switching tube Sa3 , the emitter of the second auxiliary switching transistor Sa3 is connected to the resonant inductor Lr and the first auxiliary diode Da1, and the resonant inductor Lr and the first auxiliary diode Da1 are connected in series and then connected in parallel with the main diode D1. The invention also discloses a control method for the Buck soft switch circuit for accumulator charging. The soft switching circuit of the present invention reduces switching loss.

The invention provides a resonance circuit which comprises a chopper portion and a resonance portion. The input end of the chopper portion is connected to the two ends of a DC power supply (10) so as to convert DC power input by the DC power supply (10) into AC power and output the AC power. The resonance portion comprises a capacitor (30), a transformer (40) and an inductor (50), wherein one end of the primary side of the transformer (40) is connected with the capacitor (30) in series and then connected to one output end of the chopper portion, the other end of the primary side of the transformer (40) is connected to the other output end of the chopper portion, one end of a secondary side of the transformer (40) is connected with the inductor (50) in series and then connected to one end of a load, and the other end of the secondary side of the transformer (40) is connected to the other end of the load. The resonance circuit in the embodiment of the invention realizes soft switching off of a switch tube in the chopper portion.

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.

The embodiment of the invention discloses an over-temperature protection circuit and a driving method. The circuit includes: a constant current source circuit, a comparator circuit and an output circuit, the comparator circuit includes a negative temperature coefficient resistor, a first resistor and a voltage comparator, and the comparator circuit compares the first input terminal A voltage and the value of the second voltage at the second input terminal, and output a control signal according to the comparison result, wherein the control signal is an over-temperature control signal when the temperature is greater than or equal to the protection threshold; the output circuit is used for the When the comparator circuit outputs the over-temperature control signal, it outputs a shutdown enable signal. The solution provided by the embodiment of the present invention can shut down the device in time to protect the device when the temperature is too high.

The invention discloses a passive and nondestructive clamping single-phase high-gain converter, which comprises a coupling inductor. The first end of a first winding of the coupling inductor is connected with the anode of a power supply; the second end of the first winding is connected with the drain electrode of a power switch tube and the anode of a clamping diode; the cathode of the clamping diode is connected with the first end of a clamping capacitor; the source electrode of the power switch tube is connected with the cathode of the power supply; one end of a second winding of the coupling inductor is connected with the anode of a fly-wheel diode and the cathode of the clamping diode; the second end of the second winding is connected with the first end of a double-voltage capacitor; the second end of the double-voltage capacitor is connected with the cathode of the fly-wheel diode; the first end of the second winding of the coupling inductor and the first end of the first windingof the coupling inductor serve as same name ends of the coupling inductor; the anode of an output diode is connected with the cathode of the fly-wheel diode; the cathode of the output diode is connected with the first end of an output capacitor; and the second end of the output capacitor is connected with the cathode of the power supply.

The invention relates to a power factor corrector realized in an intelligent embedded way and a control method thereof. The power factor corrector comprises a PFC (Power Factor Correction) processor with an embedded chip as core, a full wave rectifying circuit, an overcurrent protection circuit, a double-limiting voltage control circuit, a DC / DC (Direct Current / Direct Current) conversion circuit, an inductor L, a diode D, a capacitor C and a power switch tube Q. The power factor corrector realized in the intelligent embedded way, provided by the invention, has the advantages as follows: 1) duty cycle is directly stored in a chip in the form of data so as to output a PWM (Pulse Width Modulation) control wave, so that the traditional feedback circuit method is saved, a circuit structure is simplified, the usage of components is reduced and the processing process is simple and convenient; 2) the processor can be used for adjusting programs according to actual requirements in real time without frequently modifying hardware; 3) a voltage constant output function is achieved and load requirements are satisfied; 4) a remote control voltage regulating function is achieved, so that greater convenience for user in use is achieved; 5) soft startup and soft shutdown of a circuit are achieved and a circuit component is protected; and 6) overcurrent protection is achieved so that the safety of the circuit is ensured.

The invention relates to the technical field of circuits, in particularly to an interlaced on-line isolated double-cuk circuit. The interlaced on-line isolated double-cuk circuit comprises a first diode (D1), a second diode (D2), a first energy-storage inductor (L1), a second energy-storage inductor (L2), a third energy-storage inductor (L3), a fourth energy-storage inductor (L4), a first capacitor (C1), a second capacitor (C2), a first switching device MOS (metal oxide semiconductor) (Q1) and a second switching device MOS (Q2); the interlaced on-line isolated double-cuk circuit is also characterized by comprising at least a rectifier bridge, and at least two diodes and at least a capacitor are arranged between a positive output end V+ and a negative output end V- of a power supply. The invention provides an interlaced on-line isolated double-cuk circuit which has a simple structure and is convenient to operate and control.

The invention discloses a high step-up-ratio converter in bidirectional voltage outputting for a photovoltaic module. The high step-up-ratio converter comprises two switch tubes, two clamping diodes, two fly-wheel diodes, two output diodes, two clamping capacitors, one voltage-multiplying capacitor, two output capacitors and two coupling inductors, wherein the two coupling inductors are provided with two windings. According to the high step-up ratio converter disclosed by the invention, the coupling inductors are utilized for expanding the voltage gain of the high step-up-ratio converter and reducing the voltage stress of power switch tubes and the diodes, the leakage inductance of the coupling inductors is utilized for realizing zero-current switching of the switch tubes and restraining inverse restoring current of the diodes, a clamping circuit formed by the clamping diodes and the clamping capacitors is capable of effectively absorbing the voltage spike when a main switch tube is switched off and realizing the lossless transfer of energy, a voltage-multiply circuit is utilized for further increasing the gain of the high step-up-ratio converter and further reducing the voltage stress of the power switch tubes and the output diodes, the circuit control is convenient, the ripple of the input current is small, and the high step-up ratio converter is suitable for a photovoltaic grid-connected power generation conversion occasion in larger power, high gain and high efficiency.

The invention discloses a short-circuit fault detection method of a three-phase inverter, which comprises collecting the line voltage in the three-phase inverter and converting the line voltage into a phase voltage; performing DQ decoupling processing on the line voltage and the phase voltage , get the active component detection value, reactive component detection value and zero-sequence component detection value corresponding to the line voltage and phase voltage respectively; Active component standard value, reactive component standard value and zero-sequence component standard value; compare the detection value and standard value corresponding to the line voltage and the corresponding detection value and standard value of the phase voltage, and determine whether the three-phase inverter is faulty according to the comparison result ; If no fault occurs, the three-phase inverter continues to run; if a fault occurs, the location of the fault is determined according to the phase voltage and line voltage and their corresponding detection values; according to the location of the fault, the pulse blockade protection of the switch is executed Or disconnect the main contactor to stop the inverter operation and end the detection.