A Friendly Grid-connected Distribution System with PV and ESS for Remote Rural Residential Family

The study of this paper is to utilize distributed PV and energy storage system (ESS) to both extend the capacity and enhance the supply reliability of remote rural residential family distribution system. The proposed new distribution system in this paper has the highlights: The MPPTs of multi groups of PV arrays in parallel in the system are simultaneously implemented by only adjusting in real time the DC bus operation voltage, so that the topology and control of the PV generation subsystem are simplified and reduced on cost. The grid power injects under controlling into the DC bus through the accessing circuit composed of a six-phase diode rectifier with power frequency isolation transformer and a boost circuit, which uses very mature circuit and simple control to reach a higher reliability in a low-cost way comparing with the scheme using three-phase fully-controllable power electric switches rectifier. Using three single-phase DC/AC inverters, each one with power frequency isolation transformer, independent voltage amplitude control loop and coordinated voltage phase control loop, builds the three-phase DC/AC inverter, whose AC port is the type of Y0 wiring three-phase four lines, and with the capacity of tolerating power imbalances to a certain degree among phases. In this paper, the topology, functional units, operation modes and their control ways of the proposed distribution system are introduced in detail. Also, the design method and case simulation results of the proposed system are given.