Research On Induction Starter/generator System

With the development of power electronic and motion control technology, the double function starter/generator system which is made of induction machine and power electronic converter can be realized. Using induction starter/generator system as power supply system in plane, automobile, tank and steamship is becoming a new international research area.Based on the analysis of engine start torque trait, a few start schemes of induction machine are compared. In induction starter/generator system, in order to meet the demand of starter and generator simultaneously, colligation design technology is proposed. Direct torque control(DTC) in delta-connection and star-connection machine is researched and compared. The advantages and disadvantages of start about two connection are compared. Two effective current limit schemes of start about induction machine are studied.The process of voltage establish of instantaneous torque control (ITC) induction generation system is investigated. Infective factors of voltage establish process are analyzed. In ITC induction generation system, current over-shooting is produced because the vector asymmetry effect in flux and torque. The method which is by inserting short-time zero vector in the non-zero vector period to limit current over-shooting is proposed. By using this method, the process of voltage establish can realized successfully. The control scheme of voltage pump upgrade in ITC induction generation system is investigated. In induction generation system, there is a characteristic that the inductance of wind stores energy in zero voltage vector state, while the input energy from prime mover and the storeage energy in wind inductance export together in non-zero voltage vector state. Use the principle of BOOST DC/DC converter for reference, it is proposed to use this characteristic, by regulating the action time of zero voltage vector state and non-zero voltage vector state, to pump upgrade voltage in ITC induction generation system. The principle and design method of buffer circuit about power switch is researched. Performance test of middling power induction generation system is done.The conversion from starting mode to generating mode of the induction starter/generator system is researched. The system has a feature that stator flux linkage rotate speed can be fast controlled by the converter. By means of this feature, the direction of electromagnetic torque can be changed, and the system can convert from starting mode to generating mode smoothly .The conversion scheme is introduced in detail. The simulation model of induction starter/generator system has been set up with Matlab software. Whole process simulation of conversion from starting mode to generating mode has been done. Simulation results have been verified by experiment results. Double function of induction starter/generator system has been realized.Many fault diagnosis and tolerant techniques of inverter in three-phase variable frequency drive system both at home and abroad are summarized and compared , their advantages and disadvantages are pointed out. The research orientation in the future is also indicated.Familiar fault conditions of DTC induction electromotion system and ITC induction generation system are analyzed. This makes a foundation for fault detect.Two tolerant schemes for the induction electromotion system using DTC strategy are researched. The motor is driven by the inverter reconfiguration known as four-switch two-phase inverter in the first scheme and four-switch three-phase inverter in the second scheme. Control schemes of flux link and torque in DTC of four-switch systems are presented.Tolerant research of induction generation system using ITC strategy is doned. The system is reconfigurated as a four-switch three-phase(FSTP) induction generation system. The realize method of ITC strategy in FSTP induction generation system is studied. In order to improve stable performance of FSTP induction generation system, SVM-ITC (ITC based on space vector modulation) is investigated. Creation method of reference voltage vector which includes change trend and magnitude information of flux link and torque is presented. Because there is no zero voltage vector in four-switch system, a method which employs opposite vector in equal time to replace zero voltage vector is proposed. Two vector modulation schemes are presented.