Sizing and control of flywheel energy storage for Ramea wind-hydrogen-diesel hybrid power system

Abstract

In this thesis, a flywheel energy storage system (FESS) is proposed for the isolated wind-hydrogen-diesel hybrid power system in Ramea, Newfoundland, Canada. Sizing and control of the flywheel energy storage for Ramea wind-hydrogen-diesel hybrid power system is presented. At present, the hybrid power system in Ramea consists of diesel generators, wind turbines, hydrogen generator and Electrolyzer. The main objective of this proposed flywheel energy storage system is to minimize sudden variations of grid voltage and frequency due to variable wind speed and variable load. HOMER software is used for sizing and steady-state simulations, while MATLAB/Simulink is used for modeling and dynamic analysis of Ramea Hybrid power system. The selected size of the FESS is tested experimentally using a setup which is composed of 2kW DC machine based flywheel energy storage. The test DC machine is used as a motor/generator unit coupled with a cast steel flywheel rotor, a programmable data acquisition card, two controllable power supply units, two electromechanical relays and relay driving circuits. Steady state simulation shows that the addition of a flywheel energy storage to Ramea system reduces the fuel consumption by the diesel generator, reduces the excess electrical energy per year, increases the renewable penetration to the grid and reduces the number of starting the diesel generator per year. These observations can be advantageous in prolonging the life span of the diesel generator, as well as reducing its maintenance. Also the observations indicate that the voltage on the grid-side can stabilized under frequency dynamic variation.