A soft-start control device for a sensorless brushless DC motor

Abstract

A soft start control device for a sensorless brushless direct current motor is a device for conducting current controllable start and high-precision rotation speed control on the sensorless brushless direct current motor on the basis of a sensorless algorithm. The soft start control device mainly comprises a system power supply module, a FPGA (field programmable gate array) module, an interface circuit module, a back electromotive force detection module, a direct current modulation module and an inverse module. When the device starts, the winding current of the motor is controlled through the direct current modulation module, meanwhile, a position signal of a motor rotor is acquired through the back electromotive force detection module, then the FPGA module conducts PWM modulation on a three-phase bridge type inverse circuit according to the related control algorithm, and finally the high-precision rotation speed control of the brushless direct current motor based on the sensorless algorithm is implemented. The soft start control device has the sensorless high-precision control ability of the brushless direct current motor working under the high speed, realizes the complete controllability of the winding current during the motor start process, and is particularly suitable for a high-speed brushless direct current motor with the small armatureinductance.

Description

technical field [0001] The invention relates to a soft start control device for a sensorless brushless DC motor, which is used for high-precision control of the sensorless brushless DC motor, has the functions of controllable starting current and abnormal handling of external power failure, and is especially suitable for low-voltage and high-power occasions Next, Sensorless Control of High Speed ​​BLDC Motors with Small Armature Inductance. In addition, this control device is also suitable for soft start and variable frequency speed regulation control of induction motors or permanent magnet synchronous motors. Background technique [0002] In the industrial field, motor speed control systems such as blowers, compressors, and electric machine tool spindles have been widely used. Compared with other types of motors such as DC motors and induction motors, permanent magnet brushless DC motors have the characteristics of high energy density, simple control, and convenient mainte...

AI Technical Summary

Problems solved by technology

[0005] The technical problem of the present invention is to overcome the "AC-DC-AC" power topology and control algorithm of the existing sensorless brushless DC motor based on the back electromotive force detection method. During the starting process of the motor, the rotor is forced to be positioned and the frequency is increased. When the voltage is high, the starting current is large and the starting torque is uncontrollable. A sensorless brushless DC motor soft start control device based on FPGA is proposed.

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