| High voltage DC transmission transfer station has the characteristics of stable transmission power,flexible and diverse transmission methods,and can effectively avoid the emergence of unstable factors in the transmission process,so it is often used for long-distance,large-capacity transmission projects.Most of the power conversion stations in China belong to reactive power exchange stations,and a static reactive power compensation device(Station Var Company,SVC)needs to be configured to complete dynamic reactive power compensation to facilitate the stability and safety of transmission work.The SVC device can control and control voltage fluctuations,voltage flashes,power harmonics,voltage instability,etc.,so as to achieve the purpose of compensating the reactive power characteristics of the switching power station to a certain extent.The internal voltage and current of the converter station with the compensation device will not change dramatically,which will ensure the stable operation of the power system to a large extent.In this paper,the control function of this system in reactive power compensation device is analyzed,and the voltage reactive power fluctuation of weak feed system and the problem of constant voltage and filter coordination of SVC device are analyzed.The study found that the reactive power characteristics of the transfer station will cause a series of problems.The transfer station without reactive power compensation device can only use inefficient operating methods.This operating mode is not only prone to mistakes,but also greatly reduces the transmission efficiency of the power system.It is not conducive to the smooth operation of power company transmission.Based on the first and second components of HVDC converter stations,the reactive power characteristics of converter stations are systematically studied,and the SVC configuration parameters of converter stations are collated and analyzed.With the help of PSCAD \ EMTDC software,the SVC electromagnetic transient simulation model of the transfer station is built.Through the analysis of the simulation model construction work,we can see that under the specified voltage,the SVC can play a role in regulating the range of power changes,that is,by changing the TCR trigger angle formed by the SVC control modulein series with the reactance device,continuously changing the inductance current.Then obtain the purpose of stable change of reactive power.Finally,the system studies the reactive power dynamic compensation of the SVC constant voltage and input exit control under the normal operating conditions of the converter station.The SVC device can play the role of stabilizing the system voltage under the increased power of the power system.To alleviate the fluctuation of the system voltage caused by the power increase,it is helpful for the smooth and smooth operation of the system operation mode.The cooperation between the SVC device and the filter cutting strategy can effectively reduce the transient current and voltage fluctuations caused by the filter cutting operation at the UHV DC converter station,and ensure the stability and smooth operation of the transmission work. |
