Research On Dual Stator-winding Induction Generator Vector Control With Selective Harmonic Elimination Pulsewidth Modulation

With the development of more/all electric aircrafts,power systems of aircrafts also become better than before to meet the demand of higher capacity and better quality.Nowadays,the variable frequency alternative current(VFAC)power system has been the main power systems of the civil aircraft with the advantages of the good power supply quality,high reliability and light weight.Therefore,it is valuable to do research on the VFAC power system.Recently,dual stator-winding induction generator has been proposed as a novel induction machine.DWIG is quite suitable to be applied to the VFAC system for the good performance of generating.This paper does research on the vector control strategy with synchronous modulation method for DWIG.Firstly,the block diagram and mathematical models of DWIG are described.Based on it,the synchronous modulation method suitbale for DWIG is discussed.Generally,SPWM or SVPWM is often used in common electric machine control strategies.However,the switching frequency of high power IGBTs is limited in the VFAC power system,causing low carrier ratio situation.In the situation,the two asynchronous modulation methods metioned before have poor performance.So,this paper utilizes SHEPWM that is one of synchronous modulation methods.SHEPWM has fine performance in low carrier ratio and can eliminate harmonics.This paper makes some theoretical analysis on SHEPWM and obtains its harmonics characteristics by MATLAB simulation.SHEPWM is quite suitable for the control strategies that have poor dynamic performance,such as V/f control.It is general to utilize vector control for improving dynamic performance of systems.Commonly,vector control uses the structure of the outer closed loop and inner closed loop of current.The structure can not work with SHEPWM well because SHEPWM needs smooth input that closed loop of current can not give.To solve this problem,a novel vector control strategy without current loop is applied.The strategy is based on rotor field orientation and directly modifies the switching angles by controlling flux.The input of SHEPWM is given by a hybrid observer.In order to verify the proposed control strategy,the simulation model is built on MATLAB/Simulink software and a digital experimental test-bed on DSP,FPGA and CPLD for the 15 kW DWIG VFAC power system is built,too.In the paper,the hardware design of the system and software flowcharts are given in detail.The sumilated and experimental results prove the effectiveness of the proposed vector control strategy with SHEPWM for DWIG.