Delta’s ESS integrated in MHIET’s triple hybrid stand-alone power supply system

Text by: ESDBD

The world has relied on power systems with centralized power generation for over one hundred years. Overall dispatching and construction are mainly dominated by large-scale centralized power plants, and Japan is no exception. However, with the active promotion of energy saving and carbon reduction as well as falling renewable energy costs, the transformation from centralized power supply to smart power grid and a distributed power supply has become a new trend for future smart cities.

In the distributed power grid architecture, the energy storage system is an important part for the distributed power supply. The lithium ion cell and energy storage container developed by Delta’s ESDBD and a power conditioning system (PCS) developed by Delta’s EISBG are integrated into a complete energy storage system solution. Delta’s energy storage system features high reliability, high power output, rapid response and  allows to bring out functions such as load shifting, peak shaving and demand response in the power grid.

Functions the energy storage system brings into play in the power grid.

Market segments for Delta’s energy storage system include renewable energy, ancillary services, micro-grids, commercial and industrial applications and home/residential ESS.

Market segments for the energy storage system.

Through the efforts of our colleagues, Delta has achieved a number of recent successes in energy storage system solutions. For the energy storage application of renewable energy power plants, Delta built a 500kW/362kWh energy storage system at the Ako Green Energy Park in Japan in 2016 and a 1MW/1MWh system at the Taipower Yong’an Base in Kaohsiung in 2018. For micro-grid and electric vehicle charging station application, Delta built a 250kW/400kWh system at the Taipower Shulin Research Institute in 2017, and a 250kW/500kWh energy storage system that was put into operation at the CPC green energy gas station at the end of 2018.

Traditional gas turbine generators have reached a critical conversion period. To develop a stand-alone power system that is environmentally-friendly and that meets the increasing demands for the event of disaster, Mitsubishi Heavy Industries built a new type of triple hybrid stand-alone power system, EBLOX, demonstrated in Sagamihara. The Mitsubishi triple hybrid stand-alone power system adopts Delta’s energy storage system, power conditioning system and solar inverter, and combines them with a gas engine generator, which was verified from November 2018.

Configuration diagram for the Sagamihara Site.

Equipment specifications of the power supply system

Purposes of this experiment is not only to verify the stand-alone power supply system operation with triple hybrid power source, but also to verify the ability of real-time frequency containment reserve (FCR) to the primary regulating force through control center dispatching and by combining gas engine power generation facilities and energy storage system. This can be applied for Japan’s power supply and demand regulating markets in the future and to achieve the virtual power plant (VPP) concept. The verification results are as follows:
1. At the time of off-grid operation and load increase, the energy storage system can instantly compensate for the gap before the generator starts.