Analysis of Transient Voltage Characteristics of Wind-Fire Bundling DC External Transmission System

With the improvement of the modern energy system, the wind-fire bundling system combining wind power and thermal power units has become the main form of power transmission in new energy gathering areas in the northwest. However, considering the operating characteristics of the HVDC system, when a fault occurs in the near area of the HVDC system, the reactive power problem during the transient period of the system is prominent. To this end, this paper firstly builds a new energy and thermal power bundled DC system outbound transient simulation model; secondly, simulates the grounding short-circuit fault at the outlet side of the wind farm to explore the transient voltage stability of the system; The system voltage characteristics are different; finally, the system surplus reactive power consumption scheme is proposed when the HVDC system has DC blocking. The results show that the smaller the distance between the wind farm and the short-circuit point, the more obvious the voltage drop; the removal of the local compensation in the DC near zone can effectively alleviate the transient voltage rise caused by the DC blocking. The simulation model built in this paper is based on the actual power grid operation data, and has certain reference significance for the voltage stability analysis of similar grid structures.