Control strategy of a high power grid simulator for the test of renewable energy grid converter

With the increasing penetration of renewable energy generations such as solar and wind power, negative impacts of the large-scale integration of renewable energy on the bulk grid cannot be ignored. Thus, grid integration testing of inverter-coupled renewable energy is essential. For this reason, a high power gird simulator capable of emulating various types of realistic grid conditions is needed for testing multi-MW converters. This paper proposed a novel 8MW grid simulator consisting of a fundamental generator (FG) and a harmonic generator (HG), which is compatible with the voltage level from 690V to 10kV and each phase is completely independent. The proposed simulator can emulate different kinds of grid disturbances, such as voltage fluctuation and unbalance, voltage sag and swell, sudden change of the frequency, voltage distortion, etc. Control strategy to achieve the required functions is described in details and validated through simulations. The obtained results demonstrate the flexibility of the proposed approach in controlling the output voltage of the grid simulator.