Review, analysis and simulation of different structures for hybrid electrical energy storages

Output power in a hybrid power system is constant while the input power with variable characteristics that is generated by different sources. Using Hybrid Electrical Energy Storage (HEES) systems, is growing rapidly since there is an obvious need for clean energy. This paper introduces different parts of a HEES system and then proposes HEES systems which employ battery, ultracapacitor and flywheel as main energy storage devices. The behavior of a hybrid electrical energy storage including battery as the main energy storage device and a diesel generator as auxiliary energy source, also battery/flywheel and battery/ultracapacitor hybrid energy storage system with purpose of supplying load with constant power is analyzed. Results of the simulation show how well ultracapacitor and flywheel can replace battery in maintaining the load with continuous power.