Pfc Converter For Aircraft Variety-frequency Electrical Systems

Currently for the generation of constant frequency AC voltages will be replaced in future by less complex lighter variable speed generators in combination with power electronics. With the increasing requirements of performance for the modern aircraft, more and more electronic equipments are applied. The AC power utility in aircraft is affected seriously by harmonics. There are some characteristics in the AC power utility: independent lower capacity system, larger inner impedance, etc. The three-phase PWM rectifier techniques for aircraft AC power utility are unique, the good current track performance is required.First of all, the theory of PWM rectifier was introduced in details, constructing the high and low-frequency mathematical model are set up in ABC coordinate,α-βcoordinate and d-q coordinate respectively, decoupled its mathematical model in the dq reference frame. In order to restrain dc-bus voltage fluctuation and improve system dynamic characteristics, an optimum feedforward control strategy is proposed, and the system response performance to stepping input voltage and stepping load are improved greatly. The key issues which hurt the output voltage transient are analyzed in detail. The design rule for the feedforward compensation controller is developed based on the averaged small-signal model. The SVPWM is employed to achieve low harmonic distortion and raise the utilizable ratio at DC side. To verify the validity of the proposed method, the hardware system was designed on the basis of TMS320F2812 and parameters design of inductance and capacitance was presented. The experimental results are received under the different conditions. The feasibility and validity of the three-phase PWM for Aircraft Variety-Frequency Electrical Systems are proved.