Study On Transient Stability For Wind-thermal-bundled Power Transmitted By DC System

Heilongjiang Power Grid is located in the northernmost part of Northeast Power Grid in China.The installed capacity of wind power is large,and the local capacity for consumption is limited.Some wind power is sent to other areas through UHVDC in the form of wind-thermal bundling.wind-thermal-bundled power transmitted by HVDC system can improve the transmission capacity and the consumption level of renewable energy generation.This method has also brought a series of impacts on the stable operation of the power grid,which needs to be fully studied and put forward corresponding control strategies.This paper focuses on improving the transient stability of the wind-thermal bundled power transmitted by Zhalute-Qingzhou HVDC system by using HVDC power modulation technology and coordinated control among wind power,thermal power and HVDC in Heilongjiang power grid.Firstly,this paper establishes the relevant model of wind-thermal-bundled power transmitted by HVDC system,and then analyses the mechanism and implementation method of HVDC power modulation,which provides theoretical support for further research on the application of modulation methods to the transient stability analysis in Heilongjiang power grids.Secondly,combined with the actual power grid AC transmission channel failure situation,This paper analyses the influence of generator power angle and bus voltage.Through a large number of simulations,faults that have a serious impact on the transient stability of the system are obtained.Finally,from the perspective of generator power angle stability and voltage stability,This paper proposes stability control strategy combining various means.For the generator power angle stability,a parameter selection method of HVDC power modulator based on Prony analysis is proposed.The simulation results show that the proposed parameter selection method of HVDC modulator can effectively improve the generator power angle stability of Heilongjiang power grid.For voltage stability,a coordinated control strategy between wind power and HVDC is proposed.The simulation results show that the proposed coordinated control strategy has obvious effect on restraining 35kV bus overvoltage in Heilongjiang power grid.