Abstract: A power conversion device includes a first relay unit, one or more second relay units, and a safety control unit. The first relay unit includes a first logic processing unit that transmits a response signal supplied from a first power conversion unit and a response signal of a downstream side of its first relay unit to an upstream side. Each of the one or more second relay units includes a second logic processing unit that transmits a response signal transmitted from one second power conversion unit among the one or more second power conversion units and a response signal transmitted from a downstream side of the one second relay unit to an upstream side of the one second relay unit.

Abstract: A resolver signal processing device includes a deviation calculation unit, a PI operation unit, and an integration operation unit. The deviation calculation unit calculates a deviation between a first product obtained by multiplying a signal of phase A by a cosine value based on a reference phase ?ref and a second product obtained by multiplying a signal of phase B by a sine value based on the reference phase ?ref. The PI operation unit carries out a proportional integration operation which includes a first integration operation and is defined to converge the deviation on zero on the basis of the deviation. The integration operation unit carries out a second integration operation of integrating a value generated from a result of the proportional integration operation and outputs a result of the second integration operation as phase information of the resolver.

Abstract: A resolver signal processing device includes an output signal state detection unit and a disconnection detection unit. The output signal state detection unit calculates a sum of squares of a signal with a first phase and a signal with a second phase which are output signals of a two-phase output type resolver based on the output signals. The disconnection identification unit outputs information representing a disconnection state of any of a first signal system which supplies an excitation signal of the resolver and a second signal system of the output signals based on a size of a variation range in which the sum of squares periodically changes.

Abstract: A motor drive system according to an embodiment includes an inverter and a control device. The inverter causes a current to flow through a winding of an induction motor. The control device drives the induction motor by controlling the inverter through vector control. The control device includes a plurality of calculation criteria for a stator magnetic flux estimated value of the induction motor and includes an appropriate magnetic flux command generation unit that selects a calculation criterion for the stator magnetic flux estimated value that further increases a loss of the induction motor from among the plurality of calculation criteria on the basis of at least a rotation speed of the induction motor in the case of braking the induction motor.

Abstract: A resolver signal processing device includes a deviation calculation unit, a PI operation unit, and an integration operation unit. The deviation calculation unit calculates a deviation between a first product obtained by multiplying a signal of phase A by a cosine value based on a reference phase ?ref and a second product obtained by multiplying a signal of phase B by a sine value based on the reference phase ?ref. The PI operation unit carries out a proportional integration operation which includes a first integration operation and is defined to converge the deviation on zero on the basis of the deviation. The integration operation unit carries out a second integration operation of integrating a value generated from a result of the proportional integration operation and outputs a result of the second integration operation as phase information of the resolver.

Abstract: A failure diagnosis system according to an embodiment includes a first power line, a second power line, a first main contact, a second main contact, a first electrical component, a second electrical component, and a control device. The first electrical component includes a first terminal electrically connected to a second part of the first power line and a second terminal electrically connected to a third part of the second power line. A state of the first electrical component is to be switched in a case where a voltage is applied between the first terminal and the second terminal. The control device is configured to determine whether an abnormality of the first main contact exists or not based on output of a control instruction relating to the first main contact and the state of the first electrical component.

Abstract: A resolver signal processing device includes an output signal state detection unit and a disconnection detection unit. The output signal state detection unit calculates a sum of squares of a signal with a first phase and a signal with a second phase which are output signals of a two-phase output type resolver based on the output signals. The disconnection identification unit outputs information representing a disconnection state of any of a first signal system which supplies an excitation signal of the resolver and a second signal system of the output signals based on a size of a variation range in which the sum of squares periodically changes.

Abstract: A failure diagnosis system according to an embodiment includes a first power line, a second power line, a first main contact, a second main contact, a first electrical component, a second electrical component, and a control device. The first electrical component includes a first terminal electrically connected to a second part of the first power line and a second terminal electrically connected to a third part of the second power line. A state of the first electrical component is to be switched in a case where a voltage is applied between the first terminal and the second terminal. The control device is configured to determine whether an abnormality of the first main contact exists or not based on output of a control instruction relating to the first main contact and the state of the first electrical component.

Abstract: A motor drive system according to an embodiment includes an inverter and a control device. The inverter causes a current to flow through a winding of an induction motor. The control device drives the induction motor by controlling the inverter through vector control. The control device includes a plurality of calculation criteria for a stator magnetic flux estimated value of the induction motor and includes an appropriate magnetic flux command generation unit that selects a calculation criterion for the stator magnetic flux estimated value that further increases a loss of the induction motor from among the plurality of calculation criteria on the basis of at least a rotation speed of the induction motor in the case of braking the induction motor.

Abstract: A control device for a power conversion device according to an embodiment includes a drive control unit outputting a control signal based on a drive quantity command value, a drive quantity adjustment unit calculating the drive quantity command value based on a torque command for the motor, an estimated value of a stator magnetic flux of the motor, and a reference value of the stator magnetic flux of the motor, a magnetic flux observer calculating the estimated value of the stator magnetic flux of the motor, and a current observer smoothing the estimated value of the stator magnetic flux on the basis of time history data of the calculated estimated value of the stator magnetic flux, and calculating an estimated value of a current flowing through a stator winding of the motor.

Abstract: A controller for a power convertor includes: a torque command value calculation module to calculate a first torque command value to a power convertor; a torque command limit module to receive the first torque command value and generate a second torque command value obtained by correcting the first torque command value so that the first torque command value is limited to a torque limiter range. The torque command limit module sets a width between the upper limit torque value and the lower limit torque value of the torque limiter range to be smaller as a fundamental wave output frequency of the power convertor increases at least in a speed region equal to or higher than a field weakening starting point.

Abstract: In a motor drive system with inverter parallel connection, a laying cable impedance is identified by a test pulse, and a cross current suppression control gain is optimized to provide a power conversion apparatus that does not require a coupling reactor. In the motor drive system 1 in which the outputs of A-bank and B-bank inverters 20A and 20B are connected in parallel, a test pulse is outputted from the drive control unit 30 provided with the PWM controller 33 to the A and B bank inverters before operation. The laying cable impedance is identified from the DC voltage Vdc at the time of test pulse output and the response currents IA and IB. An adjustment gain is calculated from the ratio of installed cable impedance to specified cable impedance. Then, the proportional gain KP is multiplied to optimize the adjustment gain, and an on-delay time based on the optimized adjustment gain GL×KP is calculated during operation.

Abstract: A control device for a power conversion device according to an embodiment includes a drive control unit controlling a current that is caused to flow through a stator winding of a motor, a drive quantity adjustment unit calculating a drive quantity command value defining a drive quantity of the motor, a magnetic flux observer calculating calculates a first estimated value of a stator magnetic flux of the motor and a first estimated value of a rotor magnetic flux of the motor, a current observer calculating a first estimated value of the current flowing through the stator winding of the motor, and an average correction unit performing calculation on the first estimated values of the stator magnetic flux of the motor. The drive quantity adjustment unit calculates a control quantity defining the drive quantity of the motor on the basis of the first estimated values of the stator magnetic flux of the motor.

Abstract: A control device for a power conversion device according to an embodiment includes a drive control unit outputting a control signal based on a drive quantity command value, a drive quantity adjustment unit calculating the drive quantity command value based on a torque command for the motor, an estimated value of a stator magnetic flux of the motor, and a reference value of the stator magnetic flux of the motor, a magnetic flux observer calculating the estimated value of the stator magnetic flux of the motor, and a current observer smoothing the estimated value of the stator magnetic flux on the basis of time history data of the calculated estimated value of the stator magnetic flux, and calculating an estimated value of a current flowing through a stator winding of the motor.

Abstract: A control device for a power conversion device according to an embodiment includes a drive control unit controlling a current that is caused to flow through a stator winding of a motor, a drive quantity adjustment unit calculating a drive quantity command value defining a drive quantity of the motor, a magnetic flux observer calculating calculates a first estimated value of a stator magnetic flux of the motor and a first estimated value of a rotor magnetic flux of the motor, a current observer calculating a first estimated value of the current flowing through the stator winding of the motor, and an average correction unit performing calculation on the first estimated values of the stator magnetic flux of the motor. The drive quantity adjustment unit calculates a control quantity defining the drive quantity of the motor on the basis of the first estimated values of the stator magnetic flux of the motor.

Abstract: A controller for a power convertor includes: a torque command value calculation module to calculate a first torque command value to a power convertor; a torque command limit module to receive the first torque command value and generate a second torque command value obtained by correcting the first torque command value so that the first torque command value is limited to a torque limiter range. The torque command limit module sets a width between the upper limit torque value and the lower limit torque value of the torque limiter range to be smaller as a fundamental wave output frequency of the power convertor increases at least in a speed region equal to or higher than a field weakening starting point.

Abstract: In a motor drive system with inverter parallel connection, a laying cable impedance is identified by a test pulse, and a cross current suppression control gain is optimized to provide a power conversion apparatus that does not require a coupling reactor. In the motor drive system 1 in which the outputs of A-bank and B-bank inverters 20A and 20B are connected in parallel, a test pulse is outputted from the drive control unit 30 provided with the PWM controller 33 to the A and B bank inverters before operation. The laying cable impedance is identified from the DC voltage Vdc at the time of test pulse output and the response currents IA and IB. An adjustment gain is calculated from the ratio of installed cable impedance to specified cable impedance. Then, the proportional gain KP is multiplied to optimize the adjustment gain, and an on-delay time based on the optimized adjustment gain GL×KP is calculated during operation.