An optimized efficiency-based control strategy for islanded paralleled PV micro-converters

This paper analyzes the operation of PV modules in islanded paralleled PV applications under different solar irradiance condition in detail. When the batteries in the system are fully charged, the PV panels only need to generate power depending on the load and may not necessarily track the maximum power point (MPP), which exists extensively. In order to optimize the system efficiency in this situation, an efficiency-based model is built and a control strategy that can distribute the output power of different PV modules to find minimum total loss of the system is proposed. The system efficiency can be optimized adaptively under different load and irradiance condition with the proposed strategy. A distributed system prototype with three converters in parallel has been built and tested. The experimental results verified the benefits of the proposed strategy.