A system and a method for driving a motor to rotate at a high speed are provided. The system includes a lookup table, a command detector, a pattern selector and a motor driver. The lookup table module is configured to store a reference waveform pattern and a modulated waveform pattern. An amplitude of the modulated waveform pattern is larger than an amplitude of the reference waveform pattern. The command detector is configured to receive a rotating speed command. The pattern selector is configured to receive the reference waveform pattern and the modulated waveform pattern, and select the reference waveform pattern or the modulated waveform pattern according to the rotating speed command. The motor driver is configured to output a driving signal to drive the motor according to the selected reference waveform pattern or modulated waveform pattern.

Devices are provided for field weakening control of a compressor, including the compressor and a main circuit unit providing power for the compressor. The devices include a compressor rotational speed obtaining unit, and a control unit that compares the rotational speed of the compressor with a rotational speed threshold 1 of the compressor, and controls the main circuit unit according to comparison results. When the rotational speed is less than 1, an output voltage of the main circuit unit is controlled at a fixed value. When the rotational speed is greater than or equal to 1, the compressor is controlled not to enter the field weakening control temporarily and the output voltage of the main circuit unit is controlled to rise, the compressor is controlled to enter the field weakening control when the output voltage of the main circuit unit cannot continue to rise.

A system and a method for driving a motor to rotate at a high speed are provided. The system includes a lookup table, a command detector, a pattern selector and a motor driver. The lookup table module is configured to store a reference waveform pattern and a modulated waveform pattern. An amplitude of the modulated waveform pattern is larger than an amplitude of the reference waveform pattern. The command detector is configured to receive a rotating speed command. The pattern selector is configured to receive the reference waveform pattern and the modulated waveform pattern, and select the reference waveform pattern or the modulated waveform pattern according to the rotating speed command. The motor driver is configured to output a driving signal to drive the motor according to the selected reference waveform pattern or modulated waveform pattern.

Disclosed herein are a motor control apparatus and method. The motor control apparatus includes a compensation signal generator configured to apply a DC-Link voltage (V.sub.Link) for driving a motor to a parameter map preset in order to estimate a gain and phase of a motor torque ripple generated when the motor is driven according to a motor command current and a motor rotation speed, and to generate a compensation signal (i.sub.comp) for compensating for the motor torque ripple corresponding to a current input motor command current (i.sub.q*), motor rotation speed (.sub.m), and DC-Link voltage (V.sub.Link), and a current controller configured to control the current of the motor by controlling an inverter such that a compensation command current (i.sub.q*.sub._comp), generated by reflecting the compensation signal (i.sub.comp), in the motor command current (i.sub.q*), coincides with a motor drive current (i.sub.q) supplied to the motor from the inverter.

A motor control device controls an induction motor driving a spindle of a machine tool, and includes: a spindle control unit that controls a rotational position or rotational speed of the spindle, and a secondary magnetic flux of the induction motor in accordance with an operation command based on an operation program of the machine tool; an advance detection unit that pre-reads the operation program, and detects a change in the operation command requiring to increase the secondary magnetic flux of the induction motor in advance; and an advance change unit that causes the secondary magnetic flux of the induction motor to increase prior to a change in the operation command in the spindle control unit, in a case of a change in the operation command being detected by the advance detection unit.

A motor controlling circuit is provided. A first terminal of a first high-side transistor and a first terminal of a second high-side transistor are coupled to a common voltage. A first terminal of a first low-side transistor is connected to a second terminal of the first high-side transistor. A first node between the first terminal of the first low-side transistor and the second terminal of the first high-side transistor is connected to a first terminal of a motor. A first terminal of a second low-side transistor is connected to a second terminal of the second high-side transistor. A second node between the first terminal of the second low-side transistor and the second terminal of the second high-side transistor is connected to a second terminal of the motor. The driver circuit regulates at least one of the transistors such that no current flows to the common voltage.

A propulsion system for an aircraft or other vehicle can include an electric motor with a rotor and a stator. A cooling arrangement for the electric motor can include one or more of: a heat sink that is disposed within an internal area of the motor and that supports, within the internal area, one or more power-electronic components for operation of the electric motor; and a plurality of flow channels that are formed along at least one of the rotor and the stator. The flow channels can be arranged to route ambient air past the at least one of the rotor and the stator during operation of the aircraft or other vehicle.

The electro-mechanical actuator of a wind turbine is configured to be powered from a DC link intermediate circuit. A method for controlling the actuator includes: determining whether a voltage demand and a power demand for operating the electro-mechanical actuator at a specific operating point can be met by an output of a first converter. The first converter is connected to a supply grid and configured to provide a first voltage and a first power to the DC link intermediate circuit; and, when the voltage demand and the power demand cannot be met, triggering a boost mode of a second converter connected between the DC link intermediate circuit and an energy store. The boost mode is triggered to: boost the voltage at the DC link intermediate circuit to a second voltage; and, boost the power supply to the electro-mechanical actuator via the DC link intermediate circuit to a second power.

A power conversion device and a press apparatus capable of preventing an excessive current in a DC-link capacitor are provided. The power conversion device 10 includes a voltage-doubling rectifier circuit 12. In the voltage-doubling rectifier circuit 12, in a voltage-doubling rectification mode, a common connection node Nc between two capacitors 102a and 102b is connected to a predetermined node. A current detector circuit 107 detects a switching current (IL) flowing in the switching elements SW1 and SW2, and a current detector circuit 108 detects a load current Ild of a load 15. In a mode switching period from a full-wave rectification mode to a voltage-doubling rectification mode, a controller circuit 110 controls the switching of the switching elements SW1 and SW2, based on the switching current (IL) and the load current Ild.

A motor control device controls an induction motor driving a spindle of a machine tool, and includes: a spindle control unit that controls a rotational position or rotational speed of the spindle, and a secondary magnetic flux of the induction motor in accordance with an operation command based on an operation program of the machine tool; an advance detection unit that pre-reads the operation program, and detects a change in the operation command requiring to increase the secondary magnetic flux of the induction motor in advance; and an advance change unit that causes the secondary magnetic flux of the induction motor to increase prior to a change in the operation command in the spindle control unit, in a case of a change in the operation command being detected by the advance detection unit.