Heat Pump Integrated On-Board Charger

This paper looks at ways to functionally integrate the onboard charger (OBC) into the heat pump (HP) of an electric vehicle (EV). This allows the heat pump hardware to assume two functions: powering the heat pump’s compressor and serving as an on-board charger converting alternating current from the grid to direct current for the battery. This high level of functional integration can reduce car level system complexity, volume and weight – opening up the possibility of reducing material usage and therefore of reducing cost and emissions, especially with vehicles intended for urban use. Prerequisites for the proposed heat pump integrated on-board chargers (HPiOBC), as an alternative to drive system integrated onboard chargers (DSiOBC), are discussed and solutions presented. Concurrent control of torque production and grid current control is identified as the enabler for HPiOBC, and possible topologies and control strategies are discussed. Finally the advantages and drawbacks of using an HPiOBC compared to using a dedicated OBC and a dedicated heat pump are summarised.