Stand-alone operation with a centralized controller for multiple PV module converters

In this paper, stand-alone control with Maximum Power Point Tracking (MPPT) control and output voltage of converter control method using Zigbee wireless communication for multiple module converters is proposed as a concept of the intelligent PV module of the photovoltaic power conditioning systems (PCS). The proposed scheme integrates all the information for a single host controller to choose which one of the entire PCS group regulates the output dc-link voltage of the converters or regulates the input voltage for the MPPT control under stand-alone condition. Individual module´s voltage and current information is periodically sampled and transferred to Zigbee module of a centralized inverter. Then, the information is delivered to the main controller through SCI (Serial Communication Interface) operation. After the transmission process, the central Digital-Signal Processor (DSP) operates the MPPT control and the output voltage regulation for each converter. In grid connected condition, every module performs the MPPT for its own PV panel. The technical benefits of the proposed approach are its flexibility to handle the blackout or sudden disconnection of grid. Also it can decrease the material cost and simplify the monitoring and supervising process through Machine-to-machine (M2M) cloud infrastructure for smart-grid test-bed. Also the method can communicate with other equipment or home appliance under the M2M cloud infrastructure. For the experimental validation of the proposed stand-alone control, multiple Zigbee wireless communication module, as well as a DSP, dual-module solar simulator, and couple of boost converter prototype are utilized.