Research On The Matrix Converter And The Matrix Converter In Wind Generation Control System

The matrix converter(MC) is a novel power converter and has many distinct advantages:(1) the MC can provide sinusoidal current input and voltage output simultaneously;(2) the phase of input current can be adjusted in advance, lag or equivalent to the input voltage;(3) the magnitude and frequency of the output voltage and the input power factor can be independently adjusted with the MC;(4) the MC is AC/AC direct converter without the DC part and possesses the capability of bi-directional power flow.Research has been done to the mathmatic principles, the basic topology, the exiting modulation algorithm, the communication problem of the MC. An overall analysis of the MC control algorithm is presented. They are switching function method, instantaneous value method and space vector control method. Their advantage and disadvantage are analyzed.The brushless doubly-fed wind generation system excited by MC is a perfect project in the variable speed constant frequency wind energy conversion system. The realization of decoupling control of the active power and reactive power in the system is a key problem to improve stability and feasibility of the system. Power research of brushless doubly-fed wind generator system based on the MC is put forward and studied. The instantaneous active power and reactive power of MC are researched in two axis reference frame. According to the maximum wind power capture strategy of wind energy conversion system and the mathematical model of the active power and reactive power of brushless doubly-fed machine (BDFM), a new type of power control system is developed based on the back propagation(BP) neural networks. The simulation model of the system is established with Matlab/Simulink software. With the system of power decoupling control, the simulation results show that the active power and reactive power are successfully controlled independently. The system has the fast dynamic response, perfect static characteristics and good robustness. The feasibility of control strategy is verified by the good performance of the controller. Base on the detailed study of the MC and the BDFM, the model reference fuzzy adaptive control of brushless doubly-fed wind generator based on the MC is put forward. The MC is used to control voltage magnitude and frequency of control winding of brushless doubly-fed machine(BDFM), in order to supply excitation for wind generator system. The model reference fuzzy adaptive control strategy is used to control the ratio of voltage versus frequency to modulate machine rotor speed and power factor. The simulation model of the system is established with Matlab/Simulink software. The simulation result has proved the fast dynamic reaction and perfect static characteristics of the system. The validity, feasibility and stability of the system design are proved by simulation research. It is advantageous to realistic application of MC in the future. A kind of good foundation was given for the design and effective real-time control of the large-scale wind power generation system. The system can highly improve the performance of the AC adjustable speed system and reduce the pollution to the power network.Based on the theoretically research, experimental research has been done to the MC. A 5kW experimental prototype was successfully built up. The prototype comprises hardware part and software part. The hardware part is made up of main circuit, buffer circuit, detecting circuit of input and output voltage, detecting circuit of output current, control circuit of DSP and CPLD, sampling circuit of ADS8364 and control panel circuit of PHILIP single chip processor. The software part includes control algorithm program and communication program. Some circuit experiment has been completed. The validity, feasibility and stability of the system design were proved by experimental research. It is advantageous to realistic application of MC in the future.The research work has been supported by the important research projects funded by national natural science foundation of China (60534040) and Guangdong science grant(A10506003, A10502004).