A Bidirectional On-Board Charger (BOBC) is a device that enables two-way energy transfer between an electric vehicle (EV) and the power grid. BOBCs not only convert AC power from the grid into DC power to charge the vehicle's battery but can also discharge energy from the battery back into the grid or household loads. This facilitates applications such as Vehicle-to-Grid (V2G), Vehicle-to-Home (V2H), and Vehicle-to-Load (V2L).

Because EV AC charging systems are predominantly installed in residential settings, the mainstream AC BOBC configurations in Europe and the U.S. differ accordingly. Europe commonly uses a 22kW three-phase 400V line voltage system, while the U.S. typically employs a 19.2kW single-phase three-wire 240V/120V system. Notably, U.S. BOBCs often require phase currents of up to 80A. Given these conditions, manufacturers aiming to test AC BOBC products on a global scale must consider a wide range of factors, including the design of the AC power source and AC load, output configuration, current handling capabilities, rated power, and equipment footprint — making for a significant technical challenge.

The Chroma 61815, a 3U/15kVA high power density grid simulator, addresses these challenges with versatility. It can function both as an AC source to simulate utility power and, with an optional AC load mode, mimic household appliances or other load characteristics. By connecting two 61815 units in parallel paired with a special wiring connection box, users can easily achieve a streamlined AC test setup in a 10U rack height with a simple three-phase four-wire output design. This setup supports both European 22kW three-phase and U.S. 19.2kW single-phase three-wire configurations. For V2G, V2H, and V2L testing scenarios, the Chroma 61815 allows seamless one-click switching between AC source and AC load modes. It can simulate various grid conditions (such as frequency and voltage fluctuations) and diverse load behaviors to address the wide-ranging AC testing requirements of BOBC systems.