Hyundai Mobis has developed an on-board, bi-directional charger for plug-in vehicles. The bi-directional onboard charger (OBC) allows the vehicle to supply electricity in its battery to the grid.
The power supplied by the vehicle can also be used as emergency power in homes. If more than enough power is supplied, it is possible to prevent a large power outage. In Korea, the amount of industrial damage caused by power outages is estimated to be 650 billion won ($570 million) per year.
The bi-directional OBC uses an AC㏒DC converter and step-up / step-down converter to convert direct current and alternating current in both directions and to synchronize voltage and power frequency with the power grid.
The actual vehicle verification begins with a dedicated charging station diagnosing the power state of the vehicle, such as battery efficiency and capacity. The optimal V2G schedule is then created according to the hypothetical scenarios in which the power supply, cost, and load are analyzed.
The vehicle receives the data signal and repeats charging and discharging according to a predetermined schedule.
The Hyundai Mobis bi-directional OBC is the same size as the conventional charger of the Ioniq (which Hyundai Mobis supplies to Hyundai), but with increased the energy efficiency. Both the charge and discharge outputs have achieved 6.6kW the same level of technology as Japan.
The industry estimates that if 100,000 V2G-powered vehicles are deployed, they will be able to secure 500MW of electricity equivalent to the power generation capacity of a thermal power plant. Currently, V2G is in pilot projects in Japan, Denmark, U.S. and China.
Hyundai Mobis participated in the V2G demonstration project initiated by KEPCO in 2015, and was responsible for the development of two-way OBC. Hyundai Mobis is the first company to develop two-way OBC in a plug-in car in Korea and to verify its safety performance and commercialize it through demonstration projects.
V2G is expected to be commercialized in Korea by 2020. The company aims to cut the size of the two-way OBC by half and lower the energy loss rate even further, according to Ahn Byung-ki, executive director of Hyundai Mobis Eco-Design Department.
Hyundai Mobis has been supplying on board chargers for the Ioniq and Niro since 2016.
The Hyundai Mobis bi-directional OBC is same size as the conventional charger of the Ioniq (which Hyundai Mobis supplies to Hyundai), but with increased the energy efficiency. Both the charge and discharge outputs have achieved 6.6kW the same level of technology as Japan.
In future smart cities, many electric vehicles will be charged at the same time. To reduce the resulting power load, V2G is essential. The successful development of the bi-directional OBC enabled Hyundai Mobis to respond more proactively to the global V2X (Vehicle To Everything, including V2G) market, which is expected to grow to 30 trillion won ($26.7 billion) by 2025.
The electricity generated by the vehicles can be supplied to homes and towns so they can be used as emergency power. The four electric vehicles can supply power enough to 20 homes to use all day.
Hyundai Mobis officials said if the power chargers are applied to the vehicles, they automatically charge them when are not in use with the bi-directional chargers acting as energy storages.
The cars are used during the day, while the vehicles can charge their batteries at night when power rates are cheaper. They can also sell their stored power during the day when power rates are higher, Hyundai Mobis officials said.