Mixed Series-Parallel Connected Current Source Converters with Interleaved SPWM

Current source converter (CSC) is widely used in high power application. To increase the system power rating, both series or parallel connection can be adopted and implemented easily. In this paper, a mixed series-parallel CSC structure was proposed for high power application. An interleaved sinusoidal pulse-width modulation (SPWM) was adopted for the mixed system to simultaneously improve the DC-link voltage quality and achieve multilevel AC output, which can potentially reduce the size of DC-link differential inductance and AC output filter. Meanwhile, the system reliability can be significantly improved due to modularity of SPWM and inherent short-circuit protection of CSC. With these advantages, the proposed mixed series-parallel CSC structure can be an attractive candidate for high-voltage direct current (HVDC) and wind power applications. Simulation and experiment results verified the effectiveness of the novel mixed series-parallel CSC system with interleaved SPWM.