Control method for maximum torque current rate of induction motor

Abstract

The invention discloses a control method for maximum torque current rate of an induction motor, belonging to the technical field of induction motor control. According to the control method, when the induction motor is at a working condition of light load running, PI (Proportional-Integral) and forecasting function control are combined so as to obtain a novel control method which can be applicable for a multi-input-multi-output system, control quantity output from a forecasting function controller serves as an input signal of an inverter circuit to change output voltage of an inverter, so that motor rotation speed is controlled, and tracking control on the rotation speed of the induction motor is achieved. The control method has the advantages of high control accuracy, fast tracking speed, low steady-state error and high interference resistance, the induction motor can be guaranteed to be endowed with high stability and dynamic performance, and the running efficiency of the motor at a dynamic condition can be improved.

Description

technical field [0001] The invention relates to a method for controlling the maximum torque-current ratio of an induction motor, in particular to a method for controlling the maximum torque-current ratio of an induction motor based on multivariable PI predictive function control, and belongs to the technical field of induction motor control. Background technique [0002] The induction motor transmission system has become the most widely used transmission system due to its ruggedness, low price, and high reliability. The electric energy consumed by the three-phase cage induction motor accounts for more than 90% of the electric energy consumed by all industrial motors. Typically, induction motors are engineered to achieve maximum efficiency at around 75% of rated load, and close to maximum efficiency at rated load. However, when running in a low load area, especially when the load rate is lower than 50%, the efficiency of the motor will drop rapidly. Therefore, induction mot...

AI Technical Summary

Problems solved by technology

The motor system is a typical control system with multiple variables, strong coupling, and complex dynamic process. It is also difficult to establish an accurate mathematical model, but at the same time it is a fast system. The traditional predictive control has a large amount of online calculation, poor real-time performance, and may be accompanied by unknown Control law, not suitable for speed control of induction motors

However, there are no literatures and reports on combining and extending PI and predictive function control to MIMO systems and applying it to induction motor control.

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