Frequency based control of electric water heaters in small PV-diesel hybrid mini-grids

Renewable energy sources (RESs) such as wind and photovoltaic (PV) can be cost effective to meet part of the energy needs of autonomous power systems (mini-grids). However, their fluctuating characteristics increase the challenge to diesel genset(s) to balance supply and demand in systems like remote communities that already present a highly variable load. This paper discusses the use of demand side management (DSM), by means of frequency controlled electric water heaters (EWHs), to minimize this issue. Its impact on a residential type PV-diesel mini-grid is demonstrated for various conditions by means of simulation with PSCAD.