Boost-based power amplifier for power-hardware-in-the-loop simulations

Power-hardware-in-the-loop (PHIL) simulation technique allows part of the simulation circuit to be realized using a physical hardware. It has a real-time software component and a hardware component which work like one unit. A power amplifier is one of the most fundamental interface blocks in a PHIL simulation. It converts a low power signals received from the software simulator to a high power signal. This high power signal drives the hardware component of the simulation and is called hardware under test (HUT). Generally, power amplifiers are constructed using buck based topology due to their large signal linear control-to-output characteristics. However, their major drawback is that the output voltage amplitude is always smaller than the applied dc-input in linear modulation region. In this paper, a boost converter based topology known as differential boost inverter (DBI), which does not suffer from the aforementioned limitations of a buck based amplifier, is used as power amplifier for PHIL simulations. However, the DBI exhibits non-linear control-to-output characteristic and cannot be used for PHIL simulations as such. A feedback linearization technique known as dynamic linearizing modulator is used to linearize the control-to-output behavior of a DBI. Experimental result verifies that the proposed power amplifier exhibits superior dynamic performance and it is used in PHIL simulations for various power HUTs.