How a hybrid power amplifier using power hardware-in-the-loop technologies can perform studies on highly resonant grid phenomena

Power Hardware-in-the-Loop (PHIL) systems are an essential part of the test equipment for energy systems. The PHIL shall be able to reproduce the fast effects of small encapsulated networks and operate with high efficiency even in energy recovery situations. An integral part of the PHIL is the power amplifier. The choice of amplifier determines the main performance of the PHIL system. There are two main groups of amplifiers, linear and switched, which offer different performance characteristics. The linear amplifier offers high bandwidth and fast response time compared to the switch-mode amplifier, while the switched amplifier offers higher efficiency and energy recovery at a lower cost. By combining these two groups, the advantages of both can be matched to make the best choice for the desired PHIL application. In this consequence, the authors present a fast PHIL system with a hybrid amplifier that provides high efficiency, bandwidth and energy recovery. The paper gives an insight into the system structure, deals with the hybrid amplifier, the additional variable line impedance and highlights the control system.