Abstract:
A hybrid AC-DC nanogrid system with PV and battery storage is designed,
to fulfill most of the nanogrid’s energy requirement from renewable energy source
(RES) installed in the building itself i.e., from solar energy. Of late, most of the
modern loads like LED based lighting loads, digital computer, television, mobile
phone chargers, BLDC Fans, electric vehicle charger, modern refrigerators and air
conditioning units require DC for its function. In a conventional system the DC from
the RES converts to AC and then converts back to DC with a series of unnecessary
conversion stages. The number of conversion stages can be reduced by directly
providing multiple levels of DC buses (for low voltage loads, HV loads & Medium
Voltages loads) along with conventional AC bus (230 V, 50 Hz) for the AC loads
(Heating loads, AC motors etc.). This process will improve the reliability of the
system significantly. This system requires a bidirectional DC-DC converter for the
designing of DC Buses. Initially the system is designed using cascaded buck boost
bidirectional converter and is then modified with switched capacitor interleaved
bidirectional converter to reduce ripples, voltage stress and to improve the efficiency
