A study of electric power quality using storage system in distributed generation

This paper describes a method to improve the power quality of a distributed generation (DG) power system. The proposed method uses a power storage system with DG. Here, DG is assumed the renewable energy systems such as photovoltaic generation (PV), wind power generation (WG) and fuel cells (FC), etc. The effect to use the storage battery is shown by the following two experiments. One case is the examination of a power transmission simulator. Another case is an experiment in a small-scale actual system. The electric power quality (frequency, voltage) is observed, when the storage battery have been introduced or not. In case of a power transmission simulator, the frequency control is executed using two methods; a power demand estimation method and a proportion control method that uses frequency deviation. The control of the storage battery is executed by using these controls. Another case is an examination for a real power system, which is the 12th pavilion of Aichi Institute of Technology (AIT). In this pavilion, photovoltaic generation (PV), wind power generation (WG) and storage batteries have been introduced. And the electric power is supplied by these sources. The electric power qualities in two cases were compared. One case is the storage battery is introduced. Another case is without the storage battery. The storage battery executes the control that maintains the voltage in the power system. As a result, it has been understood that the electric power quality has improved, when the storage battery is introduced.