Sensorless permanent magnet synchronous motor and starting method therefor

Abstract

The invention discloses a sensorless permanent magnet synchronous motor and a starting method therefor. The sensorless permanent magnet synchronous motor is connected with a driving controller; the starting method is characterized by comprising the following steps of S10), enabling the driving controller to start a motor winding short-circuit brake mode to lower the rotary speed of the motor; S20), detecting the induced current of the motor through a sampling module of the driving controller; S30) judging whether the induced current of the motor is less than a preset set value or not, if so, performing a step S40), or otherwise, performing the step S10); and S40), performing open-loop starting control. By adoption of the starting method, reliable start in a single-resistor sampling condition can be realized, so that the cost and size of the driving controller are effectively lowered; meanwhile, quick and low-current efficient start without wind can be realized and reliable start in harsh downwind and adverse wind conditions can be ensured; and furthermore, the starting method can be realized based on a single algorithm, so that an extra hardware structure is not needed.

Description

technical field [0001] The invention belongs to the field of motor control, and in particular relates to a starting method of a sensorless permanent magnet synchronous motor. The invention also relates to a sensorless permanent magnet synchronous motor applying the starting method of a sensorless permanent magnet synchronous motor. Suitable for all kinds of fan systems. Background technique [0002] The permanent magnet synchronous motor sensorless control technology has the advantages of simple implementation, low cost and high reliability, so it is widely used in various fan systems. [0003] Since the back electromotive force of the permanent magnet synchronous motor is very small under the condition of zero speed or low speed, the existing sensorless permanent magnet synchronous motor usually adopts open-loop start-up control when starting. After the motor rotor is pulled to synchronization and reaches a certain speed Then switch to closed-loop FOC control (that is, vec...

AI Technical Summary

Problems solved by technology

However, under harsh conditions, especially when starting against the wind, the motor is subjected to a high external torque, and short-circuit braking may only reduce the motor to a lower speed but cannot completely stop it (that is, reduce the motor speed to zero), so in this case, the existing start-up method that relies solely on short-circuit braking of the motor windings may cause open-loop start-up failure

Images