Abstract: A detection circuit is provided to output a feedback signal and a adjustment current when a voltage of a high-voltage side main terminal of a semiconductor switching device is equal to or higher than a preset threshold value in a period in which a gate drive circuit turns off the semiconductor switching device to cut off a current, a control circuit diagnoses a state of the semiconductor switching device or controls a signal to be outputted to the gate drive circuit, on the basis of the feedback signal, and a gate current, which is an output of the gate drive circuit, is adjusted by the adjustment current.

Abstract: A semiconductor driving device includes: a control unit which generates an ON/OFF command for a semiconductor switching element; a gate power supply unit which generates voltage to be applied between a gate terminal and a source terminal of the semiconductor switching element; a gate driving unit which applies the voltage generated by the gate power supply unit, between the gate terminal and the source terminal; and a gate leakage current detection unit which detects gate leakage current of the semiconductor switching element on the basis of voltage occurring at a gate resistor connected to the gate terminal, using a negative-side potential of the gate power supply unit as a reference.

Abstract: A power converting device includes upper-arm and lower-arm gate drive circuits which respectively drive upper-arm and lower-arm semiconductor switching elements and which respectively include upper-arm and lower-arm time point detection circuits for detecting time points at which voltages between main terminals of the upper-arm and lower-arm semiconductor switching elements have crossed respective reference voltages, and a controller including a calculator which calculates a change time point of an inverter output voltage and a PWM command pulse generator which generates, on the basis of information about the time point calculated by the calculator, a PWM command pulse to be given to the upper-arm gate drive circuit and the lower-arm gate drive circuit.

Abstract: A power conversion device includes a first switching unit connected between a DC power supply and an inverter circuit, a resonant circuit connected to the input of the inverter circuit and formed by connecting a capacitor, a reactor, and a second switching unit, and a control unit, wherein, during a resonant operation period in which the first switching unit is controlled to be off and the second switching unit is controlled to be on, the control unit controls the inverter circuit to shift from a mode in which current flows back through one of upper and lower arms of the inverter circuit to a mode in which current flows back through the other arm, and provides a period in which the upper and lower arms for every phase of the inverter circuit are turned on simultaneously.

Abstract: A power conversion device includes a first switching unit connected between a DC power supply and an inverter circuit, a resonant circuit connected to the input of the inverter circuit and formed by connecting a capacitor, a reactor, and a second switching unit, and a control unit, wherein, during a resonant operation period in which the first switching unit is controlled to be off and the second switching unit is controlled to be on, the control unit controls the inverter circuit to shift from a mode in which current flows back through one of upper and lower arms of the inverter circuit to a mode in which current flows back through the other arm, and provides a period in which the upper and lower arms for every phase of the inverter circuit are turned on simultaneously.

Abstract: An electric motor drive device includes a smoothing capacitor and an inverter, and further includes an overvoltage protection unit for overvoltage protection for the smoothing capacitor, and a phase short-circuit control unit. The overvoltage protection unit includes: a discharge circuit having a discharge resistor and an IGBT connected in series; and a first determination circuit which determines, with determination delay, that smoothing capacitor voltage exceeds first set voltage, and turns on the IGBT. The phase short-circuit control unit is provided in a control device for drive-controlling the inverter and includes a second determination circuit which determines, with a determination period longer than the determination delay of the first determination circuit, that smoothing capacitor voltage exceeds second set voltage lower than the first set voltage, to perform phase short-circuit control for the inverter.

Abstract: A power conversion device that supplies power to a load using a module incorporating a semiconductor element is such that a sealing wall that holds a sealing resin is provided on a metal case that cools the module, a feedback current channel, which is one wiring member forming a current channel that passes into and out of the semiconductor element, is the metal case, and another wiring member is disposed in proximity to and parallel with the sealing wall of the metal case.

Abstract: An electric motor drive device includes a smoothing capacitor and an inverter, and further includes an overvoltage protection unit for overvoltage protection for the smoothing capacitor, and a phase short-circuit control unit. The overvoltage protection unit includes: a discharge circuit having a discharge resistor and an IGBT connected in series; and a first determination circuit which determines, with determination delay, that smoothing capacitor voltage exceeds first set voltage, and turns on the IGBT. The phase short-circuit control unit is provided in a control device for drive-controlling the inverter and includes a second determination circuit which determines, with a determination period longer than the determination delay of the first determination circuit, that smoothing capacitor voltage exceeds second set voltage lower than the first set voltage, to perform phase short-circuit control for the inverter.

Abstract: A power conversion device that supplies power to a load using a module incorporating a semiconductor element is such that a sealing wall that holds a sealing resin is provided on a metal case that cools the module, a feedback current channel, which is one wiring member forming a current channel that passes into and out of the semiconductor element, is the metal case, and another wiring member is disposed in proximity to and parallel with the sealing wall of the metal case.

Abstract: In order to provide a communication system which performs a communication while maintaining high voltage insulation, a control circuit which is operated at a low voltage, and a controlled circuit which is operated at a high voltage are connected through a propagation layer having a waveguide structure, thereby performing a communication. In particular, a displacement current (surge current) flows between a high voltage circuit and a low voltage circuit due to a potential fluctuation which occurs in the high voltage circuit A surge current protection circuit is provided, and applying an input which is out of rating to the communication module and the low voltage circuit due to such a surge current is prevented.

Abstract: Disclosed is an electromagnetic valve driving circuit capable of reducing a load of a booster circuit. A boost driving FET 202 is connected to a route formed between the booster circuit 100 and a first terminal of an injector 3. A battery-side driving FET 212 and a battery protection diode Db are connected to a route formed between a positive-polarity side of a power supply and the first terminal of the injector 3. A freewheeling diode Df is connected at a first terminal thereof to a portion between the first terminal of the injector 3 and the battery protection diode Db, and at a second terminal thereof to a grounding side of the power supply. An injector downstream-side driving FET 220 is connected to a route formed between the second terminal of the injector 3 and the grounding side of the power supply.

Abstract: In order to provide a communication system which performs a communication while maintaining high voltage insulation, a control circuit which is operated at a low voltage, and a controlled circuit which is operated at a high voltage are connected through a propagation layer having a waveguide structure, thereby performing a communication. In particular, a displacement current (surge current) flows between a high voltage circuit and a low voltage circuit due to a potential fluctuation which occurs in the high voltage circuit A surge current protection circuit is provided, and applying of an input which is out of rating to the communication module and the low voltage circuit due to such a surge current is prevented.

Abstract: Disclosed is an electromagnetic valve driving circuit capable of reducing a load of a booster circuit. A boost driving FET 202 is connected to a route formed between the booster circuit 100 and a first terminal of an injector 3. A battery-side driving FET 212 and a battery protection diode Db are connected to a route formed between a positive-polarity side of a power supply and the first terminal of the injector 3. A freewheeling diode Df is connected at a first terminal thereof to a portion between the first terminal of the injector 3 and the battery protection diode Db, and at a second terminal thereof to a grounding side of the power supply. An injector downstream-side driving FET 220 is connected to a route formed between the second terminal of the injector 3 and the grounding side of the power supply.