Article,
Power-frequency admittance model of multi-VSGs grid-connected system considering power coupling
Affiliations
- [1] Univ Elect Sci & Technol China, Inst Elect Vehicle Driving Syst & Safety Technol, Sch Mech & Elect Engn, Chengdu, Peoples R China [NORA names: China; Asia, East];
- [2] AALBORG Univ, Dept Energy Technol, DK-9220 Aalborg, Denmark [NORA names: AAU Aalborg University; University; Denmark; Europe, EU; Nordic; OECD];
- [3] Univ Andres Bello, Fac Engn, Santiago 8370146, Chile [NORA names: Chile; America, South; OECD];
- [4] Jinling Inst Technol, Sch Elect & Informat Engn, Dept Informat Engn, Nanjing, Peoples R China [NORA names: China; Asia, East]
Abstract
The high penetration of renewable energy decreases the inertia of power systems. The virtual synchronous generator (VSG) control technology has good inertia compensation effect and has attracted considerable attention because of the similar external characteristics of synchronous generators. However, the power and frequency oscillation of multi-VSG grid-connected systems seriously threatens the stability of power system. Existing multi-VSG power frequency admittance (PFA) models ignore the power coupling caused by the large line impedance ratio in medium- and low-voltage microgrids, and the accuracy of these models needs improvement. Thus, this study aims to establish a multi-VSG grid-connected PFA model considering power coupling. The influence of power coupling on model accuracy is analyzed, and the impacts of line impedance and reactive loop coefficient on the power-frequency response characteristics are investigated. Simulation results verify that the proposed model has higher accuracy over existing models.
