A driving system of a driving motor is proposed. The system includes: a stator having slots at which coils are wound; a first inverter connected to first ends of the coils of the stator; a second inverter connected to second ends of the coils of the stator; and a stage switch circuit configured to control an electrical connection between the second ends of the coils of the stator and the second inverter. In particular, the coils include a first coil set connected to an output terminal of the first inverter, and a second coil set connected to an input terminal of the second inverter. Currents having the same phase or currents having different AC phases are applied to the first coil set and the second coil set wound at the slots by controlling on and off of the stage switch circuit.

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 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.

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 ω of the compressor with a rotational speed threshold ω1 of the compressor, and controls the main circuit unit according to comparison results. When the rotational speed ω is less than ω1, an output voltage of the main circuit unit is controlled at a fixed value. When the rotational speed ω is greater than or equal to ω1, 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 blower in one aspect of the present disclosure includes: a housing including a suction port and a discharge port; a motor in the housing; a fan in the housing; a motor drive circuit; and a control circuit. The control circuit detects an insufficient airflow from the suction port to the discharge port based on an operation parameter. The operation parameter is associated with an operation of the motor.

In an electric power steering device assisted by a brushless motor, an induced voltage from a brushless motor is detected when a main power supply is off. The motor is determined to be in a high rpm state when the induced voltage is in a first transient state from a voltage ≦a high rpm detection threshold Th1 to a voltage≧Th1, thereby setting an intermittent excitation cycle of a revolution angle sensor connected to the motor to a short cycle. The motor is determined to be in a low rpm state when the induced voltage becomes a voltage≧a high rpm detection threshold Th2 after a wait period corresponding to an electrical angle between peaks or valleys of an output voltage has elapsed in a second transient state from a voltage–Th1 to a voltage≧Th2, thereby setting the cycle to a long cycle.

In some embodiments, a system of controlling an induction electric motor, includes a command voltage output unit for generating a command voltage for operating an inverter according to a command speed and outputting the generated command voltage to the inverter; a control unit for controlling the command voltage output unit such that the command voltage output to the inverter is compared with an operation limiting voltage and the command voltage is corrected to fall within the operation limiting voltage; and the inverter for controlling the induction electric motor depending on the corrected command voltage. Thus, it is possible to precisely control the induction electric motor even in a high speed operation region by regulating the magnitude of the command voltage applied to the induction electric motor by means of dynamic modulation strategies without the magnetic flux controller.

A method of controlling an electric machine, the method comprising storing a plurality of power maps, each power map comprising control values for driving the electric machine at different power, and selecting a power map in response to an input signal. Additionally, a control system for an electric machine, and a product incorporating the control system and electric machine.

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 (ω.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 driving apparatus which drives a motor including a plurality of winding portions corresponding to a plurality of phases, respectively, includes a motor including a plurality of winding portions corresponding to a plurality of phases, respectively, a first inverter including a plurality of first switching elements and electrically connected to a first end of each of the winding portions, a second inverter including a plurality of second switching elements and electrically connected to a second end of each of the winding portions, a plurality of third switching elements including first ends electrically connected to the second ends of the plurality of winding portions, respectively, and second ends electrically connected to each other, and a controller.