Boost-based amplifier for power-hardware-in-the-loop simulations of utility-tied DG

In Power-hardware-in-the-loop (PHIL) simulations, one part of a whole network is simulated inside the Real-Time (RT) simulator and another part is in the form of actual hardware. Therefore, operation of a power Hardware-Under-Test (HUT) can be observed and analyzed when it is integrated to a larger network, without building the whole system beforehand. In this paper, a MATLAB/Simulink based toolbox is used as RT simulator for PHIL simulations. The power amplifier, another major constituent of a PHIL simulator, is constructed using boost-based topology, viz., Differential-Boost-Inverter (DBI). DBI has an advantage of generating higher output voltage compared to the applied dc-input. However, a conventional DBI exhibits nonlinear control-to-output behavior, therefore, a Dynamic-Linearizing-Modulator (DLM) is used to linearize it in large signal and dynamic sense. The linearized DLM-controlled-DBI is a suitable power amplifier for PHIL applications. The constructed PHIL simulator is used to analyze the operation of a Distributed-Generation (DG) system tied to the utility-grid. The grid network is simulated inside the RT simulator and DG is in the form of actual hardware. A proportional + resonant controller is used to control the current being injected to the grid. Experimental results in a PHIL environment show that by controlling magnitude and phase of the reference current, real and reactive power supplied to the utility-grid can be controlled.