A Robust Control Strategy for Parallel-Connected Distributed Generation Using Real-Time Simulation

In the context of renewable energy sources integration, the use of microgrids (MGs) with multiple distributed generation (DG) based on voltage source inverters is the solution to significantly reduce the influence of the unpredictable nature of the renewable energy sources on the grid. This paper focuses on the problem of uncertainties and disturbances found in such applications with various LCL filter parameters, load conditions and network conditions, and the problem of voltage control of inverter-interfaced microgrids with radial structure. The main objectives of this paper are to (i) design a robust low-order voltage controller which ensures robustness as well as desired performance of the microgrid system in spite of uncertain parameters; (ii) validate the complete model of MG under different operating conditions using a digital real-time simulator. This simulator is a beneficial tool that allows the verification of several scenarios with different operating conditions. It accelerates the testing process as compared to offline simulations, where computation time is much larger.