A solid sate power converter with sinusoidal currents in high frequency transformer for power system applications

This paper proposes a power electronic converter, with sinusoidal currents in high frequency transformer. High frequency power transformers are capable of replacing the bulky power transformers in power systems. The switching frequency of power electronic transformer, proposed in this paper, is independent of the value of leakage inductance. This is achieved with the help of a low pass filter, formed by connecting a capacitor across the secondary. High frequency switched voltage, is produced across the primary of the transformer. Sinusoidal voltage at high frequency, is obtained at secondary side, because of filter action. A matrix converter is connected to the secondary of the transformer. The switched currents at the input of the matrix converter are filtered by the capacitor. Thus, sinusoidal currents flow in the high frequency transformer. Modulation strategies for the two matrix converters at the two sides of the transformer, are explained. A mathematical model is developed to design the low pass filter. The proposed transformer has been simulated in MATLAB/SIMULINK and results have been presented.