Analysis Of Chaos Characteristics And Control Research Based On Intermediate Frequency Generator Units

Intermediate Frequency (IF) generators are very important useful in the power generation system. It can not only be directly used as IF power, but also be used as a DC power supply after the rectifier, or be used in large-scale power generation system as the excitation power. The advantages of IF generators are they can supply high-performance, stable, reliable electricity energy for a variety of special circumstances and special conditions of the electricity system as hign-performance mobile power. Excitation controller which has an important impact on the security and stability operations of generator units is an important component of generator units. Therefore the research of excitation controller is the key issue of IF generator power-supply technology development.This thesis is based on the IF generater units excitation controller project which is developed by Northeastern University and an aerospace science and technology group. Design 75kW IF generator excitation controller based on the synchronous chopper technology, using dsPIC30F6010A as control chips.The excitation circuit of excitation controller has adopted a new exciting way called the synchronization chopper circuit which uses MOSFET as switch instead of the traditional SCR exciting circuit. The new exciting way can better control the IF generator unit to operate stablely with dsPIC30F6010A.Synchronous chopper circuit is strongly nonlinear electrical systems, which is rich in dynamic behavior. In some certain parameters, it will have a chaotic situation. Synchronous chopper circuit provides excitation current for excitating winding as exciting main circuit. Its stability has important impact for generator units'operation. So the analysis and study of chaos phenomenon of such non-linear circuit systems are very important. And the research can also be better deeply understanding on the behavior of electronic circuits, and facilitate the project design.In this thesis, the main works are shown as follow:1. Through operating characteristics'research of IF generator units, Bring up the the overall plan of IF generator excitation controller.2. Using dsPIC30F6010A as the core controller and alternating sampling techniques, design IF generator excitation controller which excitation current is controller by synchronized chopper circuit. 3. Studies on the synchronized chopper converter by building its state-space equation and discrete-map model. By numerical simulation and bifurcations map, the bifurcations and chaos phenomenon can be discovered under the certain conditions. Analyze the stability of the converter by Jacobi matrix, and which are consistent to simulation analysis.4. Study the features of synchronous chopper converter on a chaotic state, OGY method and delay feedback control method are used respectively to control chaos in synchronous chopper converter. Analyze and compare the features and effects of each control method.