Control device and method for low-loss high-power pure square wave brushless DC motor

Abstract

The invention relates to a control device and method for a low-loss high-power pure square wave brushless DC motor. The control device employs the phase control voltage regulation modulation of a three-phase thyristor to replace a traditional PWM modulation mode, so that a conventional three-phase inverter bridge circuit for controlling a brushless DC motor only works in a commutation state of thebrushless DC motor. The motor control device comprises a three-phase AC power supply, a thyristor rectifying circuit, a brushless DC motor position detector, a three-phase inverter bridge circuit, avoltage and current detection circuit, a starting controller, a commutation pulse controller and a thyristor rectifying controller. The motor control device not only solves the problem that a multi-pole high-power pure square wave brushless DC motor cannot be driven to rotate at a high speed in a PWM modulation mode, but also greatly reduces the switching loss of a circuit, reduces the working temperature of equipment, and remarkably improves the system stability.

Description

technical field [0001] The invention relates to motor control technology, in particular to a low-loss high-power pure square-wave brushless DC motor control device and method. Background technique [0002] At present, the speed regulation methods of the existing small and medium power permanent magnet brushless DC motors are generally PWM modulation such as PWM_ON, ON_PWM, H_ON_L_PWM, PWM_ON_PWM, etc. In order to achieve a better pure square wave brushless DC motor control effect, this modulation method often requires three The full control device in the phase inverter bridge works at a higher switching frequency to achieve a higher dynamic effect; but when controlling a high-power permanent magnet brushless DC motor, the voltage and current are compared with those of small and medium power permanent magnet brushless DC motors. The brush DC motor will be greatly improved. Usually, a full-control device with a large voltage and current specification is used in the three-phase...

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Problems solved by technology

[0005] Aiming at the deficiencies and defects in the current control of high-power pure square-wave brushless DC motors, the present invention proposes a low-loss high-power pure square-wave brushless DC motor control device and method, using phase-controlled voltage regulation of three-phase thyristors The modulation replaces the traditional PWM modulation method, so that the three-phase inverter bridge circuit only works in the commutation state of the brushless DC motor, which solves the problem of high-power pure square wave brushless DC motor under the traditional PWM modulation method. When the switching device is working, its switching frequency cannot meet the problem of driving multiple high-power pure square-wave brushless DC motors to rotate at high speed

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