Control system and control method of brushless DC motor

Abstract

The invention relates to the controlling technique of a three-phase direct current motor, which aims at solving the problem that the existing technique can not realize good electric current closed-loop control of a three-phase square-wave brushless direct current motor. The invention provides a novel proposal for realizing electric current closed-loop control of the square-wave brushless permanent magnet direct current motor, particularly comprises a brushless direct current motor controlling system, a controlling method and a corresponding inversing module. The cathodes of freewheeling diodes D1, D3, D5 are independent from each input end of self switch pipe and mutually connected in parallel to a sampling coil L2, and / or the anodes of freewheeling diodes D4, D6, D2 are independent from each output end of a self switch pipe and mutually connected in parallel to a sampling coil L3. The invention can adopt a single resultant current sensing device to completely continuously take sampleof three-phase electric current when the motor is conducted and freewheeled, and continuous closed-loop control can be carried out to three-phase electric current by a single electric current closed-loop regulating device, therefore, dynamic and static indexes of the motor are greatly increased.

Description

technical field [0001] The present invention relates to the control technology of three-phase DC motors, more specifically, to an inverter module for controlling a brushless DC motor, a brushless DC motor control system using the inverter module, and a control method for the system; The scheme of the invention is especially suitable for the servo control of the three-phase square wave brushless permanent magnet DC motor. Background technique [0002] The square wave brushless permanent magnet DC motor is a special brushless DC motor, and its phase current and air gap magnetic field are approximately square waves or trapezoidal waves. For a brushless DC permanent magnet motor driven by three phases and six states, the forward conduction angle of each phase winding is 120°, stop at 60°, then reverse conduction at 120°, stop at 60°, and so on. Among them, the current of each phase winding is discontinuous. This discontinuous current characteristic makes the current closed-loop...

AI Technical Summary

Problems solved by technology

However, in the prior art, good current closed-loop control for the three-phase square-wave brushless DC motor has not been realized. Therefore, in the existing high-performance servo control system, the square-wave brushless permanent magnet DC motor is usually not used, but the AC servo motors or sine wave brushless permanent magnet DC motors, the result is a significant increase in control system complexity and overall high cost

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