Permanent magnet synchronous motor control method based on second-order terminal slip form

Abstract

The invention discloses a permanent magnet synchronous motor control method based on a second-order terminal slip form. The method comprises the following steps that: S1: under a rotator coordinate system, obtaining dq shaft current id and iq; S2: obtaining a q shaft current given value iq'; S3: obtaining a load torque observation value; S4: after compensation, obtaining a q haft current given value iq<*>; S5: obtaining input voltage u[Alpha] and u[Beta] under an [Alpha] [Beta] coordinate system; and S6: adopting a space voltage vector pulse width modulation technology to convert the u[Alpha]and the u[Beta] obtained in S5 into an on-off signal used for controlling a three-phase inverter power device, and finally, driving the permanent magnet synchronous motor to operate. By use of the method, a current loop controller adopts a dead-beat controller, a speed loop adopts a two-order terminal slip form controller to realize the high-accuracy control of the permanent magnet synchronous motor, and therefore, the problem that the speed change range of the permanent magnet synchronous motor with small rotational inertia is large during load mutation or given revolving speed mutation can be solved.

Description

technical field [0001] The invention relates to the technical field of permanent magnet synchronous motors, in particular to a control method for permanent magnet synchronous motors based on a second-order terminal sliding mode. Background technique [0002] Due to its high efficiency, small size, and simple structure, permanent magnet synchronous motors have been widely used in aerospace, home appliances, electric vehicles and other fields in recent years. However, as a multi-variable, strongly coupled nonlinear system, the performance of traditional linear control such as PI control is easily affected by system uncertainty and external disturbances. Secondly, when PI control is used, the pole of the motor will change with the change of speed , so the traditional PI control cannot achieve a high-performance control characteristic in the full speed range. For general permanent magnet synchronous motors with small moment of inertia, when the load changes suddenly, the tradit...

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Problems solved by technology

However, as a multi-variable, strongly coupled nonlinear system, the performance of traditional linear control such as PI control is easily affected by system uncertainty and external disturbances. Secondly, when PI control is used, the pole of the motor will change with the change of speed , so the traditional PI control cannot achieve a high-performance control characteristic in the full speed range

For general permanent magnet synchronous motors with small moment of inertia, when the load changes suddenly, the traditional PI controller cannot suppress the load disturbance very well, resulting in a large change in the speed of the motor. Occasions, put forward higher requirements for the control system

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