Delta’s Li-ion Energy Storage Integrated into Triple Hybrid Stand-Alone Power System

July 30, 2019 by Scott McMahan

Delta Electronics announced the integration of its lithium-ion energy storage system into Mitsubishi Heavy Industries Engine & Turbocharger, Ltd. (MHIET)'s innovative triple hybrid stand-alone power supply. MHIET demonstrated the stand-alone power from the Triple Hybrid Station, a demo power plant at its manufacturing site in Sagamihara, Kanagawa Prefecture, Japan.

"The Triple Hybrid stand-alone power supply system combines renewable energy such as solar power with a reciprocating engine generator and an energy storage battery system, to allow for optimal power stabilization control. The system's main advantage is its ability to stabilize the volatile output of renewable energy by combining three types of power sources, ultimately enabling low-cost power supply provided by an environmentally-friendly, multi-purpose distributed generation system," said MHIET.

Mr. C.H. Ko, executive director of Delta Electronics (Japan), said, "As the demand for decentralized power supply continues to grow, Delta is honored to partner with MHIET to provide energy-efficient solutions and products, such as energy storage systems, power conditioning systems and photovoltaic (PV) inverters, for this unique triple hybrid demo power plant. The plant leverages renewable energy, energy storage systems, and engine generators to provide distributed power supply that can meet the needs of several applications in Japan and abroad."

The lithium-ion battery system integrated by Delta into MHIET's system boasts a faster 4C charging and discharging power rate to rapidly smooth sudden fluctuations from the solar power generation due to diverse weather conditions.

In this way, Delta says its energy storage solution enables a stable power supply to meet power demand with the aid of a reciprocating engine.

Delta is in the process of developing next-generation applications including VPP (Virtual Power Plant), self-consumption, and grid stabilization using its lithium-ion battery system along with renewable energy technologies.

The MHIET triple hybrid demonstration power plant utilizes Delta's 331kWh-container-type battery energy storage solution and four 125kW power conditioning systems. The system also employs four of Delta's 50kW PV inverters with conversion efficiency up to 98.6%.

The core battery products from Delta Electronics use the lithium-ion battery technology and are manufactured on production line that was developed and transferred from Mitsubishi Heavy Industries, Japan, and fully assembled in Taiwan. The high-rate charge and discharge enabled from 4cells is conductive to grid regulation and is also suitable to serve as a direct power source for EVs.

The power conditioning system consists of four, single 125kW power supplies operating in parallel to supply a total of 500kW power output.

Delta's bi-directional energy storage system can charge the battery from the ac-source (using an ac-dc converter) or from the dc power of a photovoltaic source. The battery can also discharge and bring power back to the grid with dc-ac inversion.

The container-type energy storage solution has a standard refrigerated container as the outer protection foundation. The internal cabinet-based design of the unit connects multiple battery modules in series to meet high voltage requirements.

The cabinet configuration and module design work with the existing air conditioning host circulation mode and the thermal insulation of the refrigerated container to sustain the internal temperature stability and extend the battery service life without consuming too much air conditioning power.

Delta's battery storage solution integrates complete battery and power management, cabinet environmental monitoring, power conversion, fire extinguishing, and other subsystems into a 20-foot or 40-foot container.