1.State Key Laboratory of Power Grid Safety and Energy Conservation (China Electric Power Research Institute),Beijing100192, China;2.National Electric Power Dispatching and Control Center, Beijing100031, China;3.North China Branch of State Grid Corporation of China, Beijing100053, China
This work is supported by National Key R&D Program of China (No. 2016YFB0900805) and State Grid Corporation of China (Key Technology Research and Demonstration of ±1 100 kV DC Transmission System, No. SGTYHT/16-JS-198).
Under the background of centralized access of large-capacity DC systems and high-penetration renewable energy, this paper studies the problem of power angle and voltage interaction instability resulted by the large power disturbance of DC system considering the impact of dynamic characteristics of photovoltaic generator. Firstly, the motion equations of generator rotor and motor load of the two-machine equivalent system are derived in theory. Then, the physical mechanisms of the system instability caused by power angle and voltage interaction after large power disturbance of DC system are analyzed. Finally, the impacts of different active/reactive power characteristics of photovoltaic generator during low voltage ride-through (LVRT) process on the system stability are studied. The results are verified through the simulation of Changji-Guquan high voltage direct current (HVDC) system in China. The study results show that the system instability is eventually resulted by the vicious circle between the relative power angle increase of generators and the load-bus voltage drop (i.e. the decrease of motor resistance). And the impact of different active/reactive power characteristics of photovoltaic generator during LVRT process on the system stability should be comprehensively analyzed by theory combined with simulation.
TU Jingzhe,YI Jun,WANG Chao,et al.Analysis on Instability Mechanism of Power Angle and Voltage Interaction Considering Dynamic Characteristics of Photovoltaic Generator[J].Automation of Electric Power Systems,2020,44(13):157-165.DOI:10.7500/AEPS20190809002Copy