A Switched-Sink Bidirectional Power Amplifier

Power Hardware in Loop (PHIL) methodology enables the flexible and risk-free testing of physical equipment. A power amplifier (PA) is essential to interface the RT simulator with the Hardware under Test (HuT). This application requires the PA to have bidirectional power transfer capability. Therefore, conventional power amplifiers cannot be used directly. The paper proposes an alternate solution to build a two-stage power amplifier with a bidirectional power flow capability. The novelty of the proposed solution is two-fold. First, a novel switched-power sink is incorporated into the PA structure to accommodate reverse power flow. Secondly, a control scheme for the switched power sink is proposed to achieve seamless transfer between the forward and reverse power modes. This switched-sink architecture provides a low-cost, low-complexity solution that is ideal for low-power applications. The operation of the proposed switched-sink PA architecture with a seamless control algorithm is verified in a lab-developed prototype.