Indirect DC link current measurement technique using an op-amp circuit in an automotive DC converter with coupled inductors

This paper presents an accurate, reliable and cost-efficient phase current sensing solution for a balancing controller implementation in an automotive multi-phase DC converter with coupled inductors and multiple DC link capacitors. An indirect DC link current measurement technique using a single current sensor with an operational amplifier circuit is described on a 5-phase buck converter example. The idea of DC link current waveform reflection of the individual phase currents is used and extended for multiple input capacitor case. This paper describes DC link current sensing and phase current reconstruction procedures for a balancing controller implementation, which are approved through simulations and experimentally.