Abstract: A failure phase of an AC current sensor is determined without providing a DC current sensor. A control device that controls a motor via an inverter circuit that supplies power converted from direct current to three-phase alternating current to the motor, in which a current sensor that detects alternating current of each phase of three-phase alternating current is provided at an output of the inverter circuit, and the control device calculates estimated DC current values by using a duty value of a PWM signal for controlling switching of the inverter circuit and an AC current value of two phases among three phases detected by the current sensor, and determines a failure of the current sensor on the basis of a change in the estimated DC current values that have been calculated.

Abstract: A failure phase of an AC current sensor is determined without providing a DC current sensor. A control device that controls a motor via an inverter circuit that supplies power converted from direct current to three-phase alternating current to the motor, in which a current sensor that detects alternating current of each phase of three-phase alternating current is provided at an output of the inverter circuit, and the control device calculates estimated DC current values by using a duty value of a PWM signal for controlling switching of the inverter circuit and an AC current value of two phases among three phases detected by the current sensor, and determines a failure of the current sensor on the basis of a change in the estimated DC current values that have been calculated.

Abstract: To carry out diagnosis of a current sensor while maintaining high reliability. An inverter control device according to the present invention controls an inverter circuit, calculates an estimated direct current value on the basis of a duty value and an alternating current sensor value output by an alternating current sensor, and performs diagnosis of a direct current sensor on the basis of the estimated direct current value and a direct current sensor value output by the direct current sensor.

Abstract: An internal electric circuit device that is connected to a connector terminal at the time of being short-circuited can be protected, but a load connected to the connector terminal has not been able to be protected. When a voltage of a cathode of a diode becomes a voltage equal to or more that an output voltage of a power source circuit by a short circuit of a positive terminal, an output voltage of an amplifier changes from the output voltage of the power source circuit to a voltage of a point connected to a negative power terminal of the OP amplifier. When the output voltage of the amplifier becomes 0 V, a voltage difference between the gate and the source of a switching element becomes equal to or more than a predetermined voltage. Therefore, the drain and the source of the switching element enter an open state, and the current flowing a negative terminal is blocked. Therefore, it is possible to protect a load from overcurrent.

Abstract: To provide a further miniaturized and densified current detection device or a power conversion apparatus including the same. A current detection device or a power conversion apparatus according to the present invention includes: a plurality of conductors corresponding to currents of a plurality of phases; and a current sensor. The plurality of conductors is formed so as to have a conductor portion in which the currents flowing in the plurality of conductors, respectively, are substantially parallel. In a cross section in a direction perpendicular to a flow direction of the current of the conductor portion, the current sensor is arranged in a region sandwiched between the plurality of conductor portions, and outputs information on a current flowing in the conductor based on a combination of magnetic field vectors generated by the plurality of currents.

Abstract: An object of the present invention is to enhance fault detection accuracy offered by a fault detection apparatus. A microcomputer reads a characteristic signal input thereto. The microcomputer compares a characteristic read from the characteristic signal with a previously established reference value. The previously established reference value represents a characteristic exhibited by a resistor that is connected with a temperature sensor circuit when the temperature sensor circuit operates normally. The microcomputer determines whether the characteristic exhibited by the resistor falls within a detection range. If it is determined that the characteristic falls with the detection range, the temperature sensor circuit is detected to be operational and information indicating that the temperature sensor circuit is operational is output to a host control apparatus.

Abstract: An object of the invention is to provide a power conversion device which secures insulation and is miniaturized still more without being affected by electromagnetic noises. A power conversion device according to the invention includes a power semiconductor module which converts a DC current into an AC current and includes a DC positive terminal and a DC negative terminal, and a resin cover portion which includes an insulating portion disposed between the DC positive terminal and the DC negative terminal. The cover portion holds a metal member which covers the DC positive terminal and the DC negative terminal.

Abstract: To carry out diagnosis of a current sensor while maintaining high reliability. An inverter control device according to the present invention controls an inverter circuit, calculates an estimated direct current value on the basis of a duty value and an alternating current sensor value output by an alternating current sensor, and performs diagnosis of a direct current sensor on the basis of the estimated direct current value and a direct current sensor value output by the direct current sensor.

Abstract: To provide a further miniaturized and densified current detection device or a power conversion apparatus including the same. A current detection device or a power conversion apparatus according to the present invention includes: a plurality of conductors corresponding to currents of a plurality of phases; and a current sensor. The plurality of conductors is formed so as to have a conductor portion in which the currents flowing in the plurality of conductors, respectively, are substantially parallel. In a cross section in a direction perpendicular to a flow direction of the current of the conductor portion, the current sensor is arranged in a region sandwiched between the plurality of conductor portions, and outputs information on a current flowing in the conductor based on a combination of magnetic field vectors generated by the plurality of currents.

Abstract: If a fault occurs in a buffer unit from which a PWM signal is outputted, an abnormal PWM signal may be outputted from the buffer unit. When a fault occurs in a first buffer unit, a fault detection unit detects a fault in the PWM signal being inputted via a second buffer unit. When the fault in the PWM signal is detected, the fault detection unit outputs a PWM fault signal to an arithmetic unit and the second buffer unit. In response to the input of the PWM fault signal, the second buffer unit sets the output thereof to high impedance and drives the inverter circuit by a protection operation PWM signal to perform protection operation of a motor.

Abstract: If a fault occurs in a buffer unit from which a PWM signal is outputted, an abnormal PWM signal may be outputted from the buffer unit. When a fault occurs in a first buffer unit, a fault detection unit detects a fault in the PWM signal being inputted via a second buffer unit. When the fault in the PWM signal is detected, the fault detection unit outputs a PWM fault signal to an arithmetic unit and the second buffer unit. In response to the input of the PWM fault signal, the second buffer unit sets the output thereof to high impedance and drives the inverter circuit by a protection operation PWM signal to perform protection operation of a motor.

Abstract: An internal electric circuit device that is connected to a connector terminal at the time of being short-circuited can be protected, but a load connected to the connector terminal has not been able to be protected. When a voltage of a cathode of a diode becomes a voltage equal to or more that an output voltage of a power source circuit by a short circuit of a positive terminal, an output voltage of an amplifier changes from the output voltage of the power source circuit to a voltage of a point connected to a negative power terminal of the OP amplifier. When the output voltage of the amplifier becomes 0 V, a voltage difference between the gate and the source of a switching element becomes equal to or more than a predetermined voltage. Therefore, the drain and the source of the switching element enter an open state, and the current flowing a negative terminal is blocked. Therefore, it is possible to protect a load from overcurrent.

Abstract: An object of the invention is to diagnose whether an overcurrent detecting function with respect to a power semiconductor element of a power conversion apparatus is normal. The power conversion apparatus of the invention is provided with IGBTs as the power semiconductor element which performs a switching operation to convert DC power supplied from a DC power source into AC power, an overcurrent detecting circuit, and an overcurrent simulating circuit. The IGBTs include an emitter sensing terminal which outputs a sense current according to a current flowing to an emitter electrode. The overcurrent detecting circuit detects the overcurrent flowing to the IGBTs on the basis of the sense current output from the emitter sensing terminal. The overcurrent simulating circuit outputs a simulation signal which simulates the overcurrent flowing to the IGBTs and toward the overcurrent detecting circuit.

Abstract: An object of the present invention is to enhance fault detection accuracy offered by a fault detection apparatus. A microcomputer reads a characteristic signal input thereto. The microcomputer compares a characteristic read from the characteristic signal with a previously established reference value. The previously established reference value represents a characteristic exhibited by a resistor that is connected with a temperature sensor circuit when the temperature sensor circuit operates normally. The microcomputer determines whether the characteristic exhibited by the resistor falls within a detection range. If it is determined that the characteristic falls with the detection range, the temperature sensor circuit is detected to be operational and information indicating that the temperature sensor circuit is operational is output to a host control apparatus.

Abstract: A diagnostic device capable of accurately diagnosing the soundness of a resolver circuit is provided. A shifter receives excitation signal and excitation signal; shifts the level of excitation signal, excitation signal, or both; and performs level shifting such that a period of time that starts with one of two times in which, in the vicinity of the peak value of excitation signal, excitation signal and excitation signal are at the same value and ends with the other of the two times is less than a prescribed threshold. A trigger generation circuit generates a trigger during said period of time. A control unit determines whether there is an abnormality in the resolver circuit on the basis of the trigger.

Abstract: An object of the invention is to provide a power conversion device which secures insulation and is miniaturized still more without being affected by electromagnetic noises. A power conversion device according to the invention includes a power semiconductor module which converts a DC current into an AC current and includes a DC positive terminal and a DC negative terminal, and a resin cover portion which includes an insulating portion disposed between the DC positive terminal and the DC negative terminal. The cover portion holds a metal member which covers the DC positive terminal and the DC negative terminal.

Abstract: An object of the invention is to diagnose whether an overcurrent detecting function with respect to a power semiconductor element of a power conversion apparatus is normal. The power conversion apparatus of the invention is provided with IGBTs as the power semiconductor element which performs a switching operation to convert DC power supplied from a DC power source into AC power, an overcurrent detecting circuit, and an overcurrent simulating circuit. The IGBTs include an emitter sensing terminal which outputs a sense current according to a current flowing to an emitter electrode. The overcurrent detecting circuit detects the overcurrent flowing to the IGBTs on the basis of the sense current output from the emitter sensing terminal. The overcurrent simulating circuit outputs a simulation signal which simulates the overcurrent flowing to the IGBTs and toward the overcurrent detecting circuit.

Abstract: A diagnostic device capable of accurately diagnosing the soundness of a resolver circuit is provided. A shifter receives excitation signal and excitation signal; shifts the level of excitation signal, excitation signal, or both; and performs level shifting such that a period of time that starts with one of two times in which, in the vicinity of the peak value of excitation signal, excitation signal and excitation signal are at the same value and ends with the other of the two times is less than a prescribed threshold. A trigger generation circuit generates a trigger during said period of time. A control unit determines whether there is an abnormality in the resolver circuit on the basis of the trigger.

Abstract: There is provided a power conversion apparatus which allows a noise current or voltage to be suppressed at a low cost and in a small size, the noise current or voltage mixing into the power conversion apparatus by propagating through a control wiring connected to an external appliance. The power conversion apparatus includes a housing, connection terminals provided on the housing, a control-circuit unit provided inside the housing, a wiring for establishing the connection between the connection terminals and the control-circuit unit, a first noise-removing unit connected between the wiring and the ground potential of the housing, and a second noise-removing unit connected between the wiring and the ground potential of the housing, and also in parallel to the first noise-removing unit.

Abstract: A power converter includes an inverter unit that includes a plurality of semiconductor switching elements constituting upper and lower arms and converts DC power into AC power; a gate driving unit that outputs, to the inverter unit, a gate signal used to drive gates of the plurality of semiconductor switching elements; a driving control unit that supplies the gate driving unit with a switching control signal used for the gate driving unit to output the gate signal; a first abnormality detection unit that performs over voltage detection of the DC power and over current detection of the AC power and temperature detection of the upper and lower arms; and a second abnormality detection unit that detects abnormality of the plurality of semiconductor switching elements of the upper arm and lower arms, wherein the driving control unit includes a first protection circuit and a second protection circuit.