A starting method of a sensorless permanent magnet synchronous motor

Abstract

The invention discloses a starting method of a senseless permanent magnet synchronous motor, comprising the following steps: S10), after short-circuiting a motor winding, detecting a motor induced current by driving a sampling module of a controller; S20), determining whether the motor induced current is less than a predetermined value of induced current, if so, proceeding to step S30), or if not,proceeding to step S40); S30), performing open-loop start control; S40), determining whether the motor is in a forward or reverse rotation state, if in the forward rotation state, proceeding to stepS50), if not, proceeding to step S60); S50), performing forward rotation closed-loop vector start control; and S60), performing reverse rotation closed-loop vector start control. The starting method ensures the fast and low-current high-efficiency start when the permanent magnet synchronous motor is stationary or tends to be stationary, realizes fast closed-loop vector control under strong downwind or upwind conditions, reduces energy consumption, shortens start time, and makes motor start smooth.

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 is especially suitable for various 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. Since the back electromotive force of the permanent magnet synchronous motor is very small at zero speed or low speed, it is difficult to accurately obtain the position angle of the motor rotor. Therefore, the existing sensorless permanent magnet synchronous After reaching synchronization and reaching a certain speed (a more accurate rotor position angle can be obtained through estimation), then switch to closed-loop FOC control (that is, vector control). [0003] Starting against and against the wind is a basic function that...

AI Technical Summary

Problems solved by technology

[0006] With the in-depth research and application of the applicant, it was discovered that when the forward rotation speed of the permanent magnet synchronous motor is high under the condition of downwind, if the technical solution of 201710291097. Controlled start-up, not only causes greater loss, but also leads to longer start-up time

In addition, in some practical applications, when the motor controller is powered off, but because the speed inertia motor has not completely stopped, the controller restarts after power supply is restored, and the motor will also start in a situation similar to that described above.

In the case of headwind, the permanent magnet synchronous motor will reverse at a high speed, and the reverse speed is proportional to the wind speed. For the sensorless controller, measures must be taken to suppress the reverse of the motor (such as 201710291097.X The motor winding short-circuit brake mode), it is difficult to generate enough starting torque in the open-loop start-up phase to pull the fan back to the forward rotation and pull it to synchronization, which leads to the fact that the fan cannot start reliably under headwind conditions

It can be seen from this that although the technical solution of the prior application 201710291097. The startup process consumes a lot of energy and takes a long time to start

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