Control Technology For High-voltage Rectifier For Ship Electric Propulsion System

Among the principal factors, concerning the control system for high-voltage rectifying for ship electric propulsion system, are the formation of the main loop of the rectifying circuit, the selection of power electronics and reasonable voltage levels, the fitting control strategy for decreasing of electric current distortion at the input side, and increasing of the power factor.Formation of the main loop. It presents three-level PWM rectifying circuits for high voltage and power. The circuit, in spite of slight complication of its constitution and control, is considered being of the obvious advantages, for example, it is much useful to reduce the distortion of the current at the input side and to improve the power factor. It also constructs the math model of the three-level rectifying circuit.Voltage-space-vector method is adopted for the control strategy. The method is suitable for high-voltage rectifying circuit, with high availability of the voltage at the DC side. The corresponding method is presented to settle problems in the . circuit such as balancing of the neutral voltage and narrow pulse width.Based on the discussion on the formation of the main loop and control strategy, the construction scheme of the control system for high-voltage rectifying circuit is presented. According to the current level of power electronics, IGCT, with 3(3.3)kv or 4.16kv, is the better. Full-digital control system, with the DSP of TMS320F240 of TI company( U.S.), is selected for forming the control system, and new algorithms are able to used in the control system to improve the performances.With the MATLAB language, being used widely at present, and Under the powerful SIMULINK platform, the control system of the three-level rectifying circuit has been simulated, based on the math model of the three-level circuit. The validity of the model and the advantages of the voltage-space-vector method has been proved.