Study On System Energy Saving Technology Of Doubly-Fed Machine Based On DSP

The twelfth and thirteenth five-year plans of the motor industry clearly pointed out that our country is promoting efficient use of motor, and system energy saving of doubly-fed machine is a means for realizing the motor operate efficiently. Based on the analyses of structure and principle, Doubly-fed Machine is studied with frequency control and consuming reactive power and established a Doubly-fed Machine control model based on its control model characteristics, the control theory of Doubly-fed Machine reactive power compensation is made. The experiment platform for Doubly-fed Machine is made by control principle of Doubly-fed Machine. At the same time, rotor excitation system and parameter measurement system of Doubly-fed Machine is designed. Frequency control and reactive power compensation of Doubly-fed Machine is used to save energy by SPWM.Through the research of the principle characteristics, start-up mode and the speed way the theory of induction motor, the Doubly-fed Machine is modeled. By the analysis of the doubly-fed machine model, the circuit model and the control model of the Doubly-fed Machine are modeled. On this basis, the control methods and strategies of the rotor excitation of the Doubly-fed Machine is researched. The frequency principles and their implementation of the Doubly-fed Machine are researched. By the use of pulse width modulation technology, rotor excitation is executed and SPWM signal is generated by regular sampling method. Reactive power compensation and principles are proposed, and its detailed analysis is given which achieve the energy-saving effect of the Doubly-fed Machine system theoretically.Then as the need of the experiment, a Doubly-fed Machine control system is designed. The system contains experimental control cabinet, the rectifier inverter system of the Doubly-fed Machine rotor excitation, the test module of the electrical parameters, and the main control chip module for reactive power compensation. Using DSP to control the part of the rotor excitation, so it can control the amplitude frequency and phase of the excitation current of the Doubly-fed Machine rotor, and build an experimental platform for the frequency control and reactive power compensation experiment of the Doubly-fed Machine.Theoretical analysis and simulation results show that the Doubly-fed Machine reactive power compensation model and control strategy is feasible. It can not only make the full use of the reserve capacity of the motor, but also output the reactive power to the grid, improve the efficiency of the system, and save energy.