Diamond Electric Develops Long Life, A6-sized 1 kW Isolated Bidirectional Charger

Isolated Bidirectional Charger Seen Contributing to Spread of EVs, Smart Grids

OSAKA (Japan) ― Diamond Electric Mfg. Co., Ltd. developed a long-life A6 sized Isolated Bidirectional Charger (IBC) in May 2019. The technology can substantially downsize and reduce the weight of the bidirectional chargers, which are essential for connecting rechargeable batteries, solar inverters, and onboard chargers, and is expected to contribute to spreading electric vehicles (EVs) and smart grids.

In recent years, increasing environmental issues and concerns have triggered renewable energy such as Photovoltaic Voltage (PV) power generation and EVs to be developed and commercialized widely. However, the large power fluctuation in the PVs and the peak demand of charging EVs cause the grid instability. Therefore, smart grids are essential for penetration of the PVs and EVs.

In response, Diamond Electric has developed the new IBC by fully utilizing its unique controlling technology. The IBC offers isolated bidirectional operation which is one of the core technologies for the Vehicle-to-Grid (V2G). The V2G utilizes onboard batteries to stabilize the grid by allowing the electricity to flow to the grid from the vehicles, thus V2G is seen as the essential technology for smart grids.

By combining our state-of-the-art technologies, ultra-compact isolated bidirectional DC/DC converter, active power decoupling, and high frequency bidirectional AC/DC converter, Diamond Electric has realized long life, A6-sized, compact IBC (104 mm x 146 mm x 32 mm excluding control circuit and heatsink). As the result, the power density is as high as 2.1 kW/L.

Furthermore, by utilizing the Diamond Electric’s and its group company Tabuchi Electric’s experiences on the grid interactive inverter, the IBC will be scaled up to the V2G onboard charger.

Expected applications

• Bidirectional onboard charger for V2G, V2H*, V2L**
• PV hybrid systems (PV + batteries)
• Uninterrupted power supply (UPS) system

^{*Vehicle-to-Home: EV supplies the power to home
**Vehicle-to-Load: EV supplies the power to the cosumer electronics}