Asynchronous motor pure electronic speed feedback method

Abstract

The invention provides an asynchronous motor pure electronic speed feedback method, which specifically comprises the following operation steps of: firstly obtaining a discrete time form expression of an asynchronous motor mathematical model, obtaining an asynchronous motor reduced order EKF (Extended Kalman Filter) speed estimation algorithm according to an extended Kalman filter algorithm, designing a FPGA (Field Programmable Gate Array) to realize a reduced order EKF speed estimation algorithm structure and carrying out hardware language VHDL (Verilog Hardware Description Language) description on the FPGA based on the described algorithm structure to obtain, send and transmit back state estimated values i alpha s, i beta s, Psi alpha r, Psi beta r and omega r to a main control DSP (Digital Signal Processor) through a port. The asynchronous motor pure electronic speed feedback method has the beneficial effects that the pressure of the main control DSP on real-time operation amount is greatly reduced, so that more storage spaces and more operation spaces are left for speed and current control; the EKF speed estimation algorithm realized by the FPGA in parallel is used for finishing within 1 microsecond, so that a less sampling period can be selected by using the speed estimation algorithm, therefore, the speed estimation precision 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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