16. Fault Ride Through and Fault Current Management for Microgrids

Over the recent years, the distributed energy resource (DER) generation and integration with utility grid became the most widely used worldwide. Thereon, the integration of distributed energy resources to the power grid and their dynamics during grid faults had become a critical issue in the new grid code requirements. In line with this, the fault ride through (FRT) capability control of grid-connected DER became the most important issue related to grid codes. There is growing interest in the industry in the application of microgrids (MGs) to take advantage of the proliferation of DER to address planning objectives such as improving resiliency and efficiency. In order to fulfill the FRT requirements imposed by grid codes, various approaches have been proposed in the last years. This chapter presents an overview of several existing FRT capability enhancement approaches during grid fault conditions and presents an FRT strategy specific for MG with an inverter-based interface (IB-MG) to maintain power exchange with distribution networks during network faults or disturbances. A uniqueness of this chapter is to outline a detailed fault current management strategy specific for MG FRT to coordinate with area utility grid, which is limiting the inverter fault current contributions and impacts on the distribution networks protection during faults or disturbances. A hardware-in-the-loop platform is proposed in this chapter for implementation and validation of MG FRT control algorithm.