Zero position self-learning method and system for position sensor of permanent magnet synchronous motor

Abstract

The invention provides a zero position self-learning method and system for a position sensor of a permanent magnet synchronous motor. The method comprises the steps of obtaining the maximum value of three-phase current of the permanent magnet synchronous motor, and obtaining a voltage amplitude through calculation according to the maximum value and a current reference value; distributing the voltage amplitude to obtain alpha and beta axis voltages (u<alpha>, u<beta>) required by each stage in the current period under a two-phase static coordinate system; controlling the permanent magnet synchronous motor by adopting SVPWM (space vector pulse width modulation) according to the (u<alpha>, u<beta>) required by each stage, and reading position signals output by a position sensor of the permanent magnet synchronous motor in each stage; and calculating a zero position compensation angle according to the position signals output by the position sensor in each stage. According to the zero position self-learning method, the zero position self-learning process in which the motor current can be controlled in a closed-loop mode and the current amplitude can be adjusted is achieved, the voltageamplitude does not need to be adjusted manually, the operation complexity is reduced, and meanwhile, the problems that the service life of the motor is shortened due to overcurrent and the motor cannot rotate due to too small current can be solved.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a zero-position self-learning method and system for a position sensor of a permanent magnet synchronous motor. Background technique [0002] Permanent magnet synchronous motors are widely used in industrial manufacturing and new energy vehicles due to their high efficiency and superior control performance. Accurate position detection is the prerequisite for permanent magnet synchronous motors to obtain superior control performance, which is usually obtained by mechanical position sensors. Due to the existence of installation errors, the position signal output by the mechanical position sensor deviates from the actual position, which needs to be compensated. [0003] The general process of obtaining the zero compensation angle is: inject voltage into the stator winding of the motor, drag the rotor to a position that coincides with the axis of the A-phase winding, and read t...

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Problems solved by technology

However, this way of adjusting the voltage amplitude multiple times increases the operational complexity of the zero compensation angle acquisition process, and when the controlled object motor is replaced, and control parameters such as control frequency and dead time are adjusted, the voltage amplitude needs to be adjusted again. Readjustment is very troublesome

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