With the rapid development of renewable energy power generation, long-distance power transmission, reactive power compensation, and AC drive applications, power electronics conversion equipment continues to increase its penetration in power systems due to its flexibility in electrical energy conversion. The system will likely appear in local power grids or even the entire power system with 100% power electronic-based power equipment, which will profoundly change the dynamic behaviour of the power system. In recent years, power systems continue to experience dynamic problems of various unknown mechanisms, posing a major threat to the safety and stability and operation of power systems.
The legacy power grids that are dynamically dominated by electrical machines are evolving as power electronic based power systems, driven by the large-scale adoption of electronic power converters for renewable generations and energy-saving applications. This radical transformation paves the way towards modern power grids with high flexibility, sustainability and improved efficiency, yet it also poses new challenges to the stability and power quality of the power system.
The research contents of this project mainly include：Current-balancing driven internal voltage motion model of voltage source converter in the stationary frame; Self and accompanying admittance model for three-phase grid-tied inverter stability analysis; The integral and simplified structural model of power system's component including component's controller; Synchronous reference frame based impedance model and stability criterion for grid-connected renewable energy generation systems; Generic reduced-order modelling hierarchy for power-electronic interfaced generators with the quasi-constant-power feature.