Interoduction: At present, there has been considerable interest in hybrid wind-solar generation system. Wind energy is the cheapest form of renewable energy and PV offers added advantage over other renewable sources and require least maintenance. Power produced by solar PV depends on solar irradiation and temperature, but it varies time to time. Also, the generation of solar power is unavailable at nighttime. Similarly, power produced by wind turbine depends on wind speed and it is not a constant. Combining more than one renewable energy sources produce an improved overall benefit compared to a system that depends on a single source. Hence the reliability of the system is improved. The northern part of Sri Lanka is suitable for this study as it has a high solar and wind power potential.

Methods and Results: Combination of solar and wind power source provide prudent form of power generation and many studies exist on this hybrid system design. Our design includes an improved control strategy that does not require any dump load. In this paper, we discuss a hybrid distributed energy system which combines both solar panel and DC wind turbine generator with battery energy storage system.  This system is designed to operate both on grid and off grid modes using the graphical user interface, PSCAD. The goal of this design is to produce a low-cost reliable system that can be used as a small scale system for northern electrification in Sri Lanka.

Conclusions: The hybrid system is designed and connected with on grid and off grid modes to a feeder of a distribution transformer located in Northern Province. The detailed concept and working principle of the hybrid system and its control were proposed. The simulation results were obtained to evaluate the dynamic performance of the hybrid system and these results clearly show that the proposed control methods can regulate the voltage and frequency within limits for various solar irradiance, wind speed and load conditions. Hence it ensures the reliability of the system.

Keywords: Distributed generation, Hybrid wind-PV&BESS system, PSCAD.