The spread of hybrid and electric vehicles is leading to the development of increasingly efficient and compact Onboard Chargers (OBCs). These devices are essential for the power transfer from the grid to the battery and vice versa. Testing is a crucial aspect of the development of such components. Grid emulators are conceived to fulfil the need of testing grid connected converters like OBCs under several circumstances. Stability analysis or validation of proper functioning under grid disturbances are examples of tests. The goal of the thesis is to design the hardware and the software components of a grid emulator with the purpose of testing a 22 kW Onboard Charger which can also achieve bidirectional power flow.