Interface Displacement and Dynamic Phasor Mapping Equivalence Based Hybrid Simulation for HVAC/DC Power Grids

In the electromagnetic transient (EMT) and transient stability (TS) hybrid simulation, the entire power system is artificially split into two sub-grids, and sub-grids interact with each other via an interface. Thus interface distortions emerge, including latency and errors. The influence of interface latency is quantitated based on a demo circuit containing delayed interaction. Moreover, the principles of improving hybrid simulation interface accuracy are concluded. Inspired by the principles, a novel interface displacement (ID) and dynamic phasor mapping equivalence (DP-ME) interface scheme is proposed. The scheme makes sub-grids at opposite sides of an interface loosely coupled and avoids interface variable form conversion by applying two techniques. 1) Displacement of the partition interface from the converter buses to the control loops and interior of the EMT sub-grid to utilize the built-in inertias. 2) Construction of the DP-ME model to calculate the injected power from EMT to TS sub-grid. Tests based on designed cases and an actual HVAC/DC power grid give credibility to the proposed ID & DP-ME scheme in comparison with full electromagnetic simulation.