A power conversion device includes an inverter, a current detector, a frequency analysis processor, a storage, a determination unit, a reference rotational rate change unit, and a rate controller. The determination unit determines a frequency at which a signal component having a magnitude exceeding a prescribed value has been detected among frequency components of a load current, generates restriction information for excluding a reference rotational rate for a rotational rate corresponding to the detected frequency based on a determination result after the determination, and causes the storage to store the generated restriction information. The reference rotational rate change unit changes a reference rotational rate of an electric motor so that mechanical resonance of the detected frequency is avoided based on the stored restriction information. The rate controller controls a rotational rate of the inverter using the changed reference rotational rate. The electric motor is driven at the controlled rotational rate.

A power conversion device includes an inverter, a current detector, a frequency analysis processor, a storage, a determination unit, a reference rotational rate change unit, and a rate controller. The determination unit determines a frequency at which a signal component having a magnitude exceeding a prescribed value has been detected among frequency components of a load current, generates restriction information for excluding a reference rotational rate for a rotational rate corresponding to the detected frequency based on a determination result after the determination, and causes the storage to store the generated restriction information. The reference rotational rate change unit changes a reference rotational rate of an electric motor so that mechanical resonance of the detected frequency is avoided based on the stored restriction information. The rate controller controls a rotational rate of the inverter using the changed reference rotational rate. The electric motor is driven at the controlled rotational rate.

A motor control actuator that drives a permanent magnet synchronous motor (PMSM) with sensorless Field Oriented Control includes a sampling circuit that generates a measurement signal by measuring a back electro motive force (BEMF) of the PMSM, while the PMSM rotates; a PLL that receives the measurement signal and extracts an amplitude and an angle of the BEMF from the measurement signal; and a motor controller that generates a first set of two phase alternating current (AC) voltage components based on an estimated rotor angle, generates a second set of two phase AC voltage components based on the amplitude and the angle, and generates control signals for driving the PMSM based on the first set of two phase AC voltage components. The motor controller performs a catch spin sequence for restarting the PMSM while rotating, the catch spin sequence includes a synchronizing period followed by a closed loop control period.

A steering control device includes a first control system and a second control system. The first control system includes and a first microcomputer. The first microcomputer is configured to compute a first command value for controlling power supply to a first coil and a second command value for controlling power supply to a second coil. The second control system includes and a second microcomputer. The second microcomputer is configured to compute the first command value and the second command value. The first microcomputer and the second microcomputer are configured to communicate the first command value and the second command value with each other. The cycle of communication between the first microcomputer and the second microcomputer is set to be equal to or shorter than each of the cycles of computations of the first command value and the second command value by the first microcomputer and the second microcomputer.

A control device for an inverter has a first inverter terminal, a second inverter terminal and a plurality of bridge branches, which bridge branches each comprise a first semiconductor, a winding terminal and a second semiconductor switch. The winding terminals are connected to a winding arrangement. The control device is configured to output a control signal which enables a first bridge branch state and a second bridge branch state in the case of at least two of the bridge branches in a first operating state, wherein, in the first bridge branch state, the second semiconductor switch assigned to the bridge branch is switched on, and wherein, in the second bridge branch state, the second semiconductor switch assigned to the bridge branch is switched off. At least two of the bridge branches are occasionally simultaneously in the first bridge branch state, and a change of said at least two bridge branches into the second bridge branch state is subsequently carried out at different points in time.

A motor controller circuit having a stable speed controlling mechanism is provided. A duty cycle determining circuit determines duty cycles of the plurality of waveforms respectively of the first waveform signals within each of a plurality of time intervals to output a duty cycle instructing signal, according to a target working period corresponding to a target rotational speed. A signal generating circuit outputs the plurality of first waveform signals according to the duty cycle instructing signal, and outputs a second waveform signal. A motor control circuit outputs a plurality of on-time signals according to the plurality of first waveform signals and the second waveform signal. A motor driving circuit is controlled to operate and drive a motor to rotate according to the plurality of on-time signals.

A motor control actuator that drives a permanent magnet synchronous motor (PMSM) with sensorless Field Oriented Control includes a sampling circuit that generates a measurement signal by measuring a back electro motive force (BEMF) of the PMSM, while the PMSM rotates; a PLL that receives the measurement signal and extracts an amplitude and an angle of the BEMF from the measurement signal; and a motor controller that generates a first set of two phase alternating current (AC) voltage components based on an estimated rotor angle, generates a second set of two phase AC voltage components based on the amplitude and the angle, and generates control signals for driving the PMSM based on the first set of two phase AC voltage components. The motor controller performs a catch spin sequence for restarting the PMSM while rotating, the catch spin sequence includes a synchronizing period followed by a closed loop control period.

A power conversion device includes an inverter, a current detector, a frequency analysis processor, a storage, a determination unit, a reference rotational rate change unit, and a rate controller. The determination unit determines a frequency at which a signal component having a magnitude exceeding a prescribed value has been detected among frequency components of a load current, generates restriction information for excluding a reference rotational rate for a rotational rate corresponding to the detected frequency based on a determination result after the determination, and causes the storage to store the generated restriction information. The reference rotational rate change unit changes a reference rotational rate of an electric motor so that mechanical resonance of the detected frequency is avoided based on the stored restriction information. The rate controller controls a rotational rate of the inverter using the changed reference rotational rate. The electric motor is driven at the controlled rotational rate.

A power conversion device includes an inverter, a current detector, a frequency analysis processor, a storage, a determination unit, a reference rotational rate change unit, and a rate controller. The determination unit determines a frequency at which a signal component having a magnitude exceeding a prescribed value has been detected among frequency components of a load current, generates restriction information for excluding a reference rotational rate for a rotational rate corresponding to the detected frequency based on a determination result after the determination, and causes the storage to store the generated restriction information. The reference rotational rate change unit changes a reference rotational rate of an electric motor so that mechanical resonance of the detected frequency is avoided based on the stored restriction information. The rate controller controls a rotational rate of the inverter using the changed reference rotational rate. The electric motor is driven at the controlled rotational rate.

A motor control actuator configured to drive a permanent magnet synchronous motor (PMSM) with sensorless Field Oriented Control (FOC) includes: a sampling circuit configured to measure a counter electro motive force (CEMF) or a back electro motive force (BEMF) of the PMSM, while the PMSM rotates, and generate a measurement signal based on the measured CEMF or the measured BEMF; a motor controller including a current controller configured to generate control signals for driving the PMSM, the current controller configured to receive the measurement signal and perform a catch spin sequence for restarting the PMSM while rotating based on the measurement signal; and a multi-phase inverter configured to supply multiple phase voltages to the PMSM based on the control signals. The motor controller is configured to match an output voltage of the multi-phase inverter to the measured CEMF or the measured BEMF during the catch spin sequence.