Investigation of direct-frequency converter

The direct-frequency converter (DFC) has more advantages than the traditional DC-link AC-DC-AC frequency converter. This paper introduces a direct-frequency converter using bi-directional switches. Its operation principle is discussed in detail and the ripple component attended by aborting the DC-link in the equivalent input voltage is analyzed. A DPWM algorithm is employed to eliminate its influence on the output voltage. Computer simulation using MATLAB/SIMULINK is also presented to examine the performance of the algorithm. At last experimental results on a three-phase 50 Hz AC input, single-phase 400 Hz AC output circuits using the TMS320F240 as the controller are provided.