Sensorless prediction torque control system and method for asynchronous motor

Abstract

The invention relates to a sensorless prediction torque control system for an asynchronous motor. The system comprises a first PI (proportional integral) controller, a model reference adaptive observer and an optimization module, wherein the first PI controller, the optimization module and the model reference adaptive observer are pairwise connected; the sensorless prediction torque control system for the asynchronous motor is connected with an inverter through the optimization module; the inverter is connected with the asynchronous motor. A reference module further comprises a sliding mode compensation module, and a torque and flux linkage prediction module is further arranged between the model reference adaptive observer and the optimization module. The system overcomes the defect of poor control accuracy of existing sensorless control for the asynchronous motor, an observation speed omega is acquired, a cost value gj of an assessment function is calculated, a reference voltage vector vs* produced when the gj is the minimum is acquired and is converted into a corresponding switching value Sa, b, c serving as control signals to control the inverter to output the optimal voltage value to the asynchronous motor, and the asynchronous motor is controlled at high precision.

Description

technical field [0001] The invention relates to a sensorless predictive torque control system and method for an asynchronous motor. Background technique [0002] The vector control of an asynchronous motor requires information on the rotational speed of the motor. The traditional AC asynchronous motor control system mostly uses magnetic field positioning control and direct torque control technology, which requires the installation of a speed sensor, which is costly, and the measurement of the rotational speed through the signal obtained by the encoder will be difficult. Problems such as errors caused by installation, measurement and transmission disturbances arise. The predictive torque control technology that has not been widely used has the advantages of intuitive and easy-to-understand algorithms, and can handle complex control tasks and multi-variable and multi-constraint control problems. It can achieve accurate and efficient motors by identifying and predicting some mo...

AI Technical Summary

Problems solved by technology

[0005] The invention provides a sensorless predictive torque control system and method for asynchronous motors, which overcomes the shortcomings of insufficient control accuracy in the existing sensorless control of asynchronous motors. And calculate the cost value g of the evaluation function j , get g j The reference voltage vector vs* at the minimum value, and convert it to the corresponding switch value S a,b,c Used as a control signal to control the inverter to output the optimal voltage value to the asynchronous motor to achieve high-precision control of the asynchronous motor

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