Research On Control System Of Winding Brushless Doubly Fed Generator

At present,variable speed constant frequency(VSCF)technology has been widely used in wind power generation and ship shaft power generation because of its advantages of high efficiency and low energy consumption.Brushless doubly-fed motor can be achieved constant frequency power generation in a wide range of speed conditions,low variable frequency capacity and high reliability.which has very high theoretical research significance.This paper takes a 4/2 pair of pole-wound rotor BDFM as the research object.Firstly,it states the basic operation principle of this system.Then,the finite element software is used to establish the prototype model and simulate the electromagnetic characteristics from the partial differential equations of the electromagnetic field and the nonlinear magnetic circuit.Then,it researches and deduces two-phase synchronous rotating coordinate system and double synchronous speed based on coordinate system respectively to simplify input-output equations of multivariable strongly coupled systems.It presents a simple and effective rotor coupling relationship,a control strategy of BDFM has been established based on this.The simulation research of speed mutation and load mutation results show that the frequency and amplitude of the power winding voltage can keep constant quickly and accurately under three conditions.Then,it utilizes the AC-DC-AC dual PWM variable frequency controller as the control winding of the power supply,and selects the power winding side converter as the research object.It designs parameters of the main circuit design and it can maintain the DC bus voltage constant when the load changes.Finally,the model of field-based electromagnetic simulation model and road-based control system of BDFM are established to build coupled magnetic-circuit finite element simulation.The dynamic response of the motor and the saturation of the motor flux density in the pure resistance load state are analyzed.It are verifies the accuracy and applicability of the control strategy.