Abstract: A diagnosis method for diagnosing a state of a motor includes an application step in which a voltage is applied to the motor on the basis of a non-rotating voltage signal that causes a rotation speed of the motor to become 0, and a measurement step in which a current supplied to the motor, to which the voltage has been applied, is measured. The diagnosis method includes a calculation step in which an electrical characteristic of the motor is calculated on the basis of the current of the motor measured by the measurement step, and a determination step in which an abnormality of the motor is determined on the basis of the electrical characteristic of the motor calculated by the calculation step and a parameter related to the non-rotating voltage signal.

Abstract: An inverter includes an arm circuit, a first capacitor, a second capacitor, a first diode, and a second diode. In the arm circuit, upper arm switching elements to which a positive electrode of a battery is connected and lower arm switching elements to which a negative electrode of the battery is connected are connected. The first capacitor has one end connected to the positive electrode of the battery. The second capacitor is connected between another end of the first capacitor and the negative electrode of the battery. The first diode has a cathode electrode connected to the connection point between the upper arm and lower arm switching elements. The second diode has a cathode electrode connected to another end of the first capacitor. Power is supplied from an external power supply to an anode electrode of the first diode and an anode electrode of the second diode.

Abstract: A power supply control apparatus includes a DC power supply including a positive electrode and a negative electrode, a load electrically connected to the DC power supply, a relay connected to a current path from the positive electrode to the negative electrode through the load in series, a switching device connected to the current path in series, and a controller controlling the relay and the switching device. The controller, in a case in which the current path is to be electrically cut off, switches the switching device to an Off state and then switches the relay to the Off state.

Abstract: A diagnosis method for diagnosing a state of a motor includes an application step in which a voltage is applied to the motor on the basis of a non-rotating voltage signal that causes a rotation speed of the motor to become 0, and a measurement step in which a current supplied to the motor, to which the voltage has been applied, is measured. The diagnosis method includes a calculation step in which an electrical characteristic of the motor is calculated on the basis of the current of the motor measured by the measurement step, and a determination step in which an abnormality of the motor is determined on the basis of the electrical characteristic of the motor calculated by the calculation step and a parameter related to the non-rotating voltage signal.

Abstract: There included are: an arm circuit in which upper arm switching elements (21, 31, 41) to which a positive electrode of a battery (70) is connected and lower arm switching elements (22, 32, 42) to which a negative electrode of the battery (70) is connected are connected; a first capacitor (10) having one end connected to the positive electrode of the battery (70); a second capacitor (11) connected between another end of the first capacitor (10) and the negative electrode of the battery (70); a first diode (12) having a cathode electrode connected to the connection point between the upper arm and lower arm switching elements; and a second diode (13) having a cathode electrode connected to another end of the first capacitor (10). Power is supplied from an external power supply (80) to the anode electrode of the first diode (12) and anode electrode of the second diode (13).

Abstract: A power supply control apparatus includes a DC power supply including a positive electrode and a negative electrode, a load electrically connected to the DC power supply, a relay connected to a current path from the positive electrode to the negative electrode through the load in series, a switching device connected to the current path in series, and a controller controlling the relay and the switching device. The controller, in a case in which the current path is to be electrically cut off, switches the switching device to an Off state and then switches the relay to the Off state.

Abstract: An object of the present invention is to reduce the conducting loss of an existing conversion circuit while suppressing its noise. The present invention is typically a circuit arrangement includes at least one switching device and a free-wheel diode connected in parallel with the switching device. The free-wheel diode is formed by connecting a silicon PiN diode in parallel with a Schottky barrier diode that uses a semiconductor material having a wider band gap than silicon as a base material. The silicon PiN diode and Schottky barrier diode are separate chips.

Abstract: The following problem associated with a semiconductor device of silicon or the like having low band gap is solved by temperature estimation using voltage drop in such a semiconductor device having low accuracy and this complicates a circuit for temperature detection suitable for practical use or a configuration for implementing a detection system. A power converter provided with an inverter circuit includes a semiconductor device whose band gap is larger than that of silicon and which has a range in which the temperature coefficient of voltage drop during conduction is positive. The power converter further includes a measurement condition setting circuit. This circuit adjusts the timing of the following measurement values used for temperature estimation at a device temperature estimation circuit to each other so that a measurement value of a voltage measurement circuit and a measurement value of a current measurement circuit become data obtained by measurement at the same time.

Abstract: A subject of the present invention is to reduce noise caused by ringing or the like while reducing turn-on power loss of the element and reverse recovery loss of the diode in a switching circuit of a power semiconductor element to which a SiC diode having small recovery current is connected in parallel. A means for solving the problem is to detect gate voltage and/or collector voltage of the power semiconductor switching element and change gate drive voltage in several stages based on the detected value.

Abstract: A circuit device includes at least one switching element and a free wheeling diode connected in parallel to the switching element. The free wheeling diode is made up of a Schottky barrier diode using a semiconductor material having a band gap larger than silicon as its base material and also a silicon PiN diode, which are connected in parallel. The Schottky barrier diode and the silicon PiN diode are provided in the form of separate chips. A circuit system is also provided wherein a diode having a Schottky junction of a compound semiconductor as a rectification element built therein is combined, and a relationship, R2>4L/C, with impedance R (resistance), L (inductance), and C (capacitance) determined by a closed circuit between a power source and a positive or negative terminal when the current of the diode becomes zero during recovery operation, is satisfied.

Abstract: An object of the present invention is to reduce the conducting loss of an existing conversion circuit while suppressing its noise. The present invention is typically a circuit arrangement includes at least one switching device and a free-wheel diode connected in parallel with the switching device. The free-wheel diode is formed by connecting a silicon PiN diode in parallel with a Schottky barrier diode that uses a semiconductor material having a wider band gap than silicon as a base material. The silicon PiN diode and Schottky barrier diode are separate chips.

Abstract: A subject of the present invention is to reduce noise caused by ringing or the like while reducing turn-on power loss of the element and reverse recovery loss of the diode in a switching circuit of a power semiconductor element to which a SiC diode having small recovery current is connected in parallel. A means for solving the problem is to detect gate voltage and/or collector voltage of the power semiconductor switching element and change gate drive voltage in several stages based on the detected value.