Low voltage ride through capability of fuel cell generation system connected to low voltage network

Abstract

New grid code is expected to require distributed generation units operating parallel with the low voltage grid to ride through low voltage event and at the same time injecting reactive current into the grid. The paper discusses and highlights the problems that could arise and explores the solutions to mitigate these problems. Simulation results show that a fuel cell generation system (FCGS) is not able to ride through very low voltage events with its standard power conditioner without operating within its design limit. Additional devices have to be included to enable continuous operation during this severe low voltage event. In meeting the requirement of reactive power support, an additional fast voltage control loop has to be added to its line side converter control. With the improvement inside its power conditioner circuit and controller, simulation results demonstrate that FCGS is capable of riding zero voltage events while at the same time adhering to new grid code requirements.