Asynchronous motor pure electronic speed feedback method

Abstract

The invention provides a pure electronic speed feedback method for an asynchronous motor. The specific operation steps are as follows: first obtain the discrete-time form expression of the mathematical model of the asynchronous motor, and then obtain the reduced-order EKF speed estimation algorithm for the asynchronous motor according to the extended Kalman filter algorithm, and then Design the algorithm structure of FPGA to realize the reduced-order EKF speed estimation. Based on the algorithm structure described above, the FPGA is described in hardware language VHDL, and the state estimated values ​​iαs, iβs, Ψαr, Ψβr, ωr are sent to the parallel port and sent back to the main control DSP. The present invention greatly reduces the pressure on the real-time calculation amount of the main control DSP, leaving more storage space and calculation space for speed and current control; and the EKF speed estimation algorithm implemented in parallel by FPGA can be implemented within 1 μs level Complete, so that the speed estimation algorithm can choose a smaller sampling period, so the speed estimation accuracy is greatly improved.

Description

technical field [0001] The invention belongs to the technical field of industrial transmission, and relates to a pure electronic speed feedback method, in particular to a method for realizing online estimation of the speed of an asynchronous motor by using a pure hardware circuit. Background technique [0002] In high-performance speed control of asynchronous motors, speed feedback signals are needed for speed closed-loop control in order to obtain fast dynamic response and high steady-state accuracy. [0003] In recent years, the rapid development of power electronics and computer technology has provided the necessary conditions for the realization of high-performance AC speed control systems. Due to the installation of speed and flux sensors, the price of the transmission system is increased, the reliability of the system is reduced, and the inherent firmness and simplicity of the asynchronous motor are destroyed. Therefore, speed sensorless control has not only become an...

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Problems solved by technology

However, since this type of method is essentially an open-loop observation method, there is no error correction link, and the shortcomings are also very obvious

The existing problems are as follows: 1) The dynamic performance of the entire transmission system cannot be guaranteed because the vector control in the dynamic process can not be guaranteed; The impact of disturbance is large; 3) For the method based on the rotor back electromotive force, the value of the back electromotive force at low speed is very small, resulting in a large error in the calculated speed

The disadvantage of the EKF speed estimation method is that the large amount of calculation is not conducive to online implementation

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