Digital Control Implementation for PV Cell-Level Inverters

This paper presents the design procedure of the digital control unit of an on-chip photovoltaic (PV) cell-level DC/AC inverter. Its main blocks are presented, along with their interconnections and timing, whereas the state diagram, based on the sinusoidal pulse width modulation (SPWM) is given, for both grid-tied and standalone operation. The proposed digital control unit is experimentally validated in a laboratory test bench, comprising four full-bridge (H-bridge) inverters in cascaded configuration. The TMS320F28379D microcontroller is employed, as it is suitable for such applications. Finally, experimental results indicate the operational characteristics of the proposed digital control scheme, being the first step for on-chip integration.