Sliding mode variable structure-based load disturbance resistance control system of bearingless induction motor

Abstract

The invention discloses a sliding mode variable structure-based load disturbance resistance control system of a bearingless induction motor. Output ends of a speed and position detector and a third 2 / 3 coordinate transformation module of a torque control section are connected to an input end of an extension sliding mode observer; an output end of the extension sliding mode observer is connected toan input end of a fractional order integration sliding mode controller; an output end of the fractional order integration sliding mode controller is connected to a second current feedback-type pulsewidth modulator through an air gap field orientation control model and a second 2 / 3 coordinate transformation module in order; the output end of the second current feedback-type pulse width modulatoris separately connected to a motor and the third 2 / 3 coordinate transformation module; and the output end of the third 2 / 3 coordinate transformation module is connected to the fractional order integration sliding mode controller through the extension sliding mode observer. Fractional order integration sliding mode is employed for substituting for an integer order integration link, and therefore, interference in a system by external disturbance is effectively reduced, rotating speed can prevent from being disturbed by load changes, and the dynamic and static performance and the load disturbanceresistance capability of the system are improved.

Description

technical field [0001] The invention is a control system of a bearingless asynchronous motor, which belongs to the field of stability control in electric transmission. Background technique [0002] Compared with other traditional motors, bearingless asynchronous motors (BIM) have the characteristics of no friction, no wear, no lubrication, corrosion resistance, long life, high-speed, ultra-high-speed operation, etc., and are widely used in life sciences where regular maintenance is difficult Fields, chemical fields susceptible to acid and alkali corrosion, and semiconductor industry and other fields. Because of its simple structure, uniform air gap, and low cost, it is used in special electrical drive and transmission fields such as machining, small and medium-sized power generation equipment, artificial heart pumps, and CNC machine tools that require high precision. However, because the BIM control system is a multivariable, nonlinear, and strongly coupled complex system, ...

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Problems solved by technology

Traditional sliding mode controllers mainly include proportional switching sliding mode controllers and integral sliding mode controllers. Proportional switching sliding mode controllers can reduce the impact of disturbances on the system, but the differential of state quantities needs to be introduced in the dynamic sliding mode surface. For a high-speed system, it is necessary to differentiate the speed, which will introduce high-frequency noise, which will affect the performance of the controller

The integral sliding mode surface does not contain the differential term of velocity, which enhances the stability of the controller. However, the traditional integral term is the first-order integer integral. When the initial error is large or the actuator is saturated, the integral saturation effect will occur, resulting in Decrease in control performance or even system instability

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