Study On Reactive Power Compensation Optimization Of DC Feed Receiver Network Considering Synchronous Condenser

Due to the uneven distribution of energy resources and productivity in China,high-voltage direct current(HVDC)has obvious advantages in long-distance transmission and is widely used in China.However,with the continuous increase of access capacity,the operation and management of the power grid is more severe.For example,the transient stability characteristics of the large-scale DC feed into the receiving power grid are weakened,and the short-circuit current exceeds the standard,which seriously threatens the safe operation of the power grid.Therefore,studying the voltage stabilityof thereceivingendsystem isan urgentproblem tobesolved.In this paper,the following research is carried out on the stability of the grid after the HVDC is fedintothereceivingend:(1)According to the problem of voltage stability caused by DC feeding,the causes of the generation are analyzed and the corresponding analysis methods are given.Static voltage stability analysis and dynamic voltage stability analysis are carried out according to different mathematical models.The analysis describes the common indicators for the stability of AC and DC systems,and derives its advantages and disadvantages.The high-voltage direct current transmission system is expounded from the principle and composition.The Davein equivalent circuit is used to construct the receivingendAC system,andthe equivalentmodelofAC/DCtransmissionsystem isestablished.(2)Analyze the influence of reactive power compensation equipment on voltage stability of different converter stations.The development history of synchronous camera and its working principle are introduced.The technical characteristics of the camera are analyzed and the inadequacies brought by the camera are obtained.And propose corresponding measures.By analyzing the influence factors of DC power receiving capacity of a real area power grid,and measuring the multi-circuit DC support capability of the receiving end system by DC multi-feed short circuit ratio.TheAC-DC power coupling relationship in this region is analyzed,and the voltage constraint analysis and commutation failure constraint analysis are carried out.The influence of the camera on the receiving capacity of the receiver is analyzed.The influence of the camera’s capacity on the DC multi-feed short-circuit ratio is studied.The simulation results show that the camera can provide emergency reactive power after the DC continuous commutation failure.The dynamic reactive power supportcapacityandtheelectrode limit ofthereceiving powergridintheregionareimproved.(3)For the problem of short-circuit exceeding the standard caused by DC feeding,how to realize the effective control of short-circuit current under the premise of ensuring the voltage stability of thepower system is carried out,and an optimal limiting short-circuit current measure considering the sensitivity dimension reduction strategy is proposed.method.Firstly,the general limiting measures and special measures of current limiting are analyzed.How to change the elements of the order network impedance matrix by different current limiting measures,and the sensitivity relationship between the current limiting measures and the short-circuit current of the over-limit nodes is analyzed.Sensitivity,a decision-making variable dimension reduction strategy is proposed.Secondly,a mathematical model that takes into account the investment cost,current limiting effect and system stability level of the current-limiting measures is established.The adaptive hybrid particle swarm optimization algorithm is used to find the optimal current-limit scheme.The effectiveness of the proposed scheme is verified by analyzing the improved IEEE9 node system and a real regional power grid.