Abstract :
Forced commutated cycloconverters (FCCs) are very popular topics today which can generate variable frequency and variable voltage in output. These converters include six switches in each phase where operation of these converters depends on switching strategy. This study describes a novel switching strategy for six switches FCC where this strategy transfers seven input voltages to FCC output. In each switching period, among seven input voltages, there are only two input voltages which surround reference output voltage. Hence, the proposed strategy makes these two input voltages around reference voltage transfer to FCC output in each switching period. As a result, average value of FCC output voltage is the same as reference voltage. Main benefits of this switching strategy are minimisation of total harmonic distortion, reduction of dv/dt stresses on the load, lower harmonic components, high-voltage modulation index and performance in unbalance or non-sinusoidal input voltage condition. The operation and performance of the proposed switching strategy has been verified by the simulation and measurement results which were carried out for three-phase to single-phase converter. The proposed switching strategy serves as the conceptual platform for extending the principles to other FCC topologies.
