A control device for power conversion device controls a power conversion device in a system driven by the power conversion device to which an electric motor outputs AC power, and includes: a control pulse generation unit configured to generate a control pulse of the power conversion device; and a negative phase creation unit configured to input a pulse signal output by the control pulse generation unit and rotational speed information of the electric motor, and to generate an inverted signal of an output signal of the control pulse generation unit, wherein the pulse signal of a half cycle during one cycle of voltage, the pulse signal being generated by the control pulse generation unit, and a pulse signal of a next half cycle during the one cycle of voltage, the pulse signal being generated by the negative phase creation unit, are symmetrical in positive and negative relationship of voltage.

A circuit assembly for linking different electrical voltage levels in a motor vehicle, comprising: an electric machine containing induction coils in a star circuit connection with a star point; a first switch unit containing switch elements for generating an AC voltage for the electric machine from a DC voltage of a first voltage level; a DC voltage of a second voltage level; and a second switch unit for a bidirectional electrical energy flow between the DC voltage of the first voltage level and the DC voltage of the second voltage level, wherein the second switch unit has two switch elements arranged in series in an auxiliary switch branch, wherein the auxiliary switch branch is connected in parallel to the DC voltage of the first voltage level, and each connection of the switch elements is connected to the star point.

A drive system has an electric motor, wherein the electric motor includes a first three-phase stator winding system and a second three-phase stator winding system. The first and the second stator winding system are arranged on the stator in a manner rotated through an electrical phase angle in relation to one another. The drive system includes a frequency converter, wherein the frequency converter has a first bridge circuit arrangement which is designed to generate voltages for the first winding system and a second bridge circuit arrangement which is designed to generate voltages for the second winding system. The first bridge circuit arrangement and the second bridge circuit arrangement are connected in series. A control device is designed to actuate the first bridge circuit arrangement and the second bridge circuit arrangement.

A power control system for a hybrid vehicle is provided. The system includes a rechargeable battery, a first motor that is connected to a driving wheel of the vehicle, and a second motor that is connected to the driving wheel of the vehicle. A first inverter is connected to the first motor and a second inverter is connected to the second motor. A converter has a first side connected to the battery and a second side connected to the first inverter. A neutral switch is connected between the first side of the converter and a neutral point of the first motor. A controller executes an on/off of the switch based on whether the first motor is operated and required power of the vehicle.

An object of the present invention is to provide an electric power steering apparatus capable of improving reliability of a drive device for a three-phase synchronous motor without increasing a cost of the drive device. A control device for controlling an electric power steering apparatus according to the present invention is a control device for controlling an electric power steering apparatus using a three-phase synchronous motor as a force assisting in a steering operation, includes: a rotational position estimation unit that estimates a position of a rotor of the three-phase synchronous motor on the basis of a neutral point potential or a virtual neutral point potential of the three-phase synchronous motor; and a command signal computing unit that computes a command signal to the three-phase synchronous motor on the basis of the position of the rotor estimated by the rotational position estimation unit.

A drive device of a compressor, including an inverter circuit formed of a plurality of switching elements, a drive unit that switches the switching elements, a determination unit that, when the compression mechanism restarts, determines whether a pressure difference of the compression mechanism is equal to or above a predetermined value, a restart unit that sets a number of times that the switching elements are switched per unit time during an initial predetermined period when the compression mechanism begins to restart and controls the drive unit, where the restart unit sets the number of times that the switching elements are switched per unit time to be lower when the determination unit determines that the pressure difference is equal to or above the threshold as compared to when the determination unit determines that the pressure difference is less than the threshold.

A power tool is provided including: an electric brushless direct current (BLDC) motor having rotor and a stator defining phases; a power unit including a first switch circuit connected electrically between a first power supply and the motor, and a second switch circuit connected electrically between a second power supply and the motor; and a controller configured to control a switching operation of the first switch circuit and the second switch circuit to regulate a supply of power from at least one of the first power supply and/or the second power supply to the motor.

A power tool is provided including: an electric brushless direct current (BLDC) motor having rotor and a stator defining phases; a power unit including a first switch circuit connected electrically between a first power supply and the motor, and a second switch circuit connected electrically between a second power supply and the motor; and a controller configured to control a switching operation of the first switch circuit and the second switch circuit to regulate a supply of power from at least one of the first power supply and/or the second power supply to the motor.

A power tool is provided including: an electric brushless direct current (BLDC) motor having rotor and a stator defining phases; a power unit including a first switch circuit connected electrically between a first power supply and the motor, and a second switch circuit connected electrically between a second power supply and the motor; and a controller configured to control a switching operation of the first switch circuit and the second switch circuit to regulate a supply of power from at least one of the first power supply and/or the second power supply to the motor.

A power tool is provided including: an electric brushless direct current (BLDC) motor having rotor and a stator defining phases; a power unit including a first switch circuit connected electrically between a first power supply and the motor, and a second switch circuit connected electrically between a second power supply and the motor; and a controller configured to control a switching operation of the first switch circuit and the second switch circuit to regulate a supply of power from at least one of the first power supply and/or the second power supply to the motor.