Control of Battery Supported Pico Hydro-PV Based Distributed Generation for Rural Electrification

The operation and control of a battery energy storage (BES) supported pico-hydro-solar photovoltaic (PV) array based isolated renewable energy system (RES) feeding 3-phase 4-wire loads is dealt in this work. For the voltage regulation, maintaining frequency, and power quality improvement in this system, a 4-leg VSC is used. The BES is connected to the DC-link of voltage source converter (VSC) through a bidirectional converter (BDC), which regulates the DC-link voltage and controls the charging and discharging current of the battery. An advanced analytical perturb and observe (AP&O) based maximum power point tracking (MPPT) control technique with drift free operation and capability to operate in de-rated mode, is adapted in this work. The VSC connected to PCC, injects or absorbs power from this system based on the difference of energy between generation and the load. The modified complex co-efficient filter (MCCF) based control technique, takes care of the power quality of this RES system and a 4-leg VSC provides source neutral current compensation. This control algorithm extracts the fundamental load current amplitude with an improved dynamic response, high DC offset elimination and higher order harmonics removal capability. The capability of this system using presented control strategy for power quality improvement, power management, load balancing and neutral current compensation is reported in this work.