Research And Simulation On Controlling Strategy Of Control Power Supply For Locative In Model CCM And DCM

The main circuit of electrical locomotive 110V direct current source is half controlled commutated circuit and the power device is GTO, which has the limitations such as low factor, big impact on power net, not convenient to maintenance and low reliability for so many devices, high gross weight and big volume. In recent years, in the railway industry, more and more widespread use of switching power supply, electric vehicle control power switching power supply has been towards the transformation of our country in the newly developed electric locomotive in the high-frequency switching power supply has been used to replace the original frequency Phase control power supply. High frequency switching power supply for electric locomotive has a small size, light weight and high efficiency.Locomotive used in this high-frequency switching power supply, the main circuit circuit towards the control of PWM soft-switching full-bridge zero-voltage modulator, using IGBT as switching devices. But because of the the study of control strategy is Inadequate, there still exist many shortcomings such as low efficiency, low reliability and not easily maintained.Firstly, this paper introduce the circuit principle of the ZVS full bridge converter and make a solutions to the problems. Each device is designed and parameters are selected of the system, the power factor correction circuit and main circuit of DC-DC converter is designed. Secondly, the model of ZVS full bridge converter is predigested because of the comparability of the ZVS converter and BUCK converter. We can get the model of the main circuit in CCM and DCM. Thirdly, we get the whole power of the mathematical model locomotive after modeling feedback network and pulse width modulator controlled.Then the paper design digital PID controller and voltage controller to locomotive main circuit switching power supply. The PID controller has simple structure and wide range of robust and able to obtain good control performance, this article using conventional PID controller. Different from the traditional method, this paper puts forward a new method to determine the PID parameters using the computer simulation. Using this method greatly improve the design efficiency. Finally through MATLAB, the contrast of the circuit simulation not participating in the PID controller and join the simulation results, PID controller that join control effect got obvious improvement, to satisfy the design requirements.