Open-loop control starting method and device for permanent magnet synchronous motor

Abstract

The invention discloses an open-loop control starting method and device for a permanent magnet synchronous motor. The method includes the following steps that: the voltage command value of a dq coordinate system is outputted; the voltage command value and a counter electromotive force direction angle output by a counter electromotive force phase-locking unit are inputted into a pulse width modulation unit, and the pulse width modulation unit outputs PWM (pulse width modulation) signals for driving the switching component of an inverter unit; a three-phase output quantity outputted by the inverter unit is converted into a two-phase output quantity in a two-phase rotating coordinate system; and the three-phase output quantity and the counter electromotive force direction angle are calculated; and the PWM pulse signals are converted into a strong electricity voltage to control the motor. With the open-loop control starting method and device for the permanent magnet synchronous motor of the invention adopted, the magnitude and direction of the counter electromotive force of the motor in starting can be locked fast and accurately, and huge impact current generated by using open-loop control to start the motor when the motor is not stopped stably can be avoided, and a hardware detection circuit can be omitted.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to an open-loop control startup method and device for a permanent magnet synchronous motor. Background technique [0002] Compared with asynchronous motors, permanent magnet synchronous motors (PMSM) have the advantages of high efficiency, small size, fast dynamic response, etc., and are replacing the application of asynchronous motors in many industrial occasions. [0003] The control technologies of permanent magnet synchronous motors currently include closed-loop vector control (VC) with encoder, encoderless vector control (SLVC), and open-loop VF control; the advantage of closed-loop vector control compared to the latter two is dynamic response Faster, higher steady-state speed accuracy, but the disadvantage is that encoders and speed feedback devices need to be added, and the equipment cost is high; at present, most industrial occasions do not have high requirements for d...

AI Technical Summary

Problems solved by technology

[0006] In view of the high cost of closed-loop vector control in the above-mentioned prior art, a very large starting current is generated when the encoderless vector control (SLVC) or open-loop VF starts, the success rate of starting is low, and the dependence on hardware measurement accuracy reduces the robustness of the system problem, the present invention provides an open-loop control startup method and device for a permanent magnet synchronous motor

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