Abstract
Cascaded H-bridge (CHB) inverters operate with isolated DC sources, which makes them a favorable topology for hybrid-interfaced applications. Parasitic capacitance of grounded photovoltaics (PV) results in leakage currents that may deteriorate the system performance and raise safety concerns. In order to address this problem, a common-mode equivalent circuit for a multilevel CHB is illustrated. The study reveals that common modulation techniques such as phase shifted pulse width modulation fail to suppress the leakage current. A unique modulation scheme, based on considering the switching states is proposed in order to ensure that the topology conforms to the transformerless inverter regulations and standards such as VDE-0126-1-1. Simulation study results for conventional and proposed modulation methods are presented and analyzed in a symmetrical grid inductance filter circuit.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
