Processor-In-Loop Based Implementation of Z-Source Inverter With Maximum Constant Boost Control

A dual stage grid tied photovoltaic (PV) system invovlves dc-dc conversion followed by dc-ac conversion. Same power structure is employed in vehicle-to-grid (V2G) interface. Though the dual stage conversion is often necessary, use of two converters results in increased component count, control complexity and converter losses. This issue can be resolved by replacing the two converters with a Z-source inverter (ZSI), which uses impedance network and shoot-through state for boosting the dc-link voltage. The paper reports processor-in-loop (PIL) based implementation of ZSI with maximum constant boost control (MCBC) scheme. PIL facilitates implementation of the control scheme on TMS320F28377S digital signal processor and the power circuit is deployed on PSIM software in quasi real-time. PIL while adopted for ZSI offers the benefits of faster computation, less dependence on physical control system. This helps testing of control as well as power circuit of the converter without being at the risk of damaging the actual system on account of the shoot-through state. Step-by-step procedure for PIL implementation is discussed in this paper. The results indicate that the PIL based design can be successfully tested without any constraints on placement of sensors or measurement devices.