Research on Performance of Real-Time Simulation Based on Inverter-Dominated Power Grid

This paper proposes two methods to improve the performance in real-time simulation. The increased inverter-based generations are gradually shifting the operation of the power grid. Consequently, the investigation for the safe operation and further application is essential in the inverter-dominated power grid. As the simulated number of non-linear switch elements like inverter increases, the numerical complexity of the simulation model rises exponentially. Accordingly, the scale of the simulated power grid with inverters is normally constricted by taking account of the burdensome numerical calculation. The emerging of real-time simulator provides the opportunity to enable the simulation of the large-scale power grids. Nevertheless, the simulation boundary condition is still exceeded in the inverter-dominated model. Hence, the improvement of the performance to extend the limitation in real-time simulation is constituted in this paper. The first method proposed is co-simulation. This approach is to simulate the power grid and inverters by models in different deep levels. The phasor model and electrical-mechanical-transient model are utilized to develop the co-simulation model. The second method is network reduction. Based on the dynamic feature of the inverter, it is reduced to an equivalent current source, which decreases the complexity of the model and retains its characteristics. The evaluation of the methods is demonstrated by two indexes: real-time capability and the similarity degree.