Research On The Optimal Configuration Of Reactive Power Compensation For Urban 330kV Cable Power Network And Unified Power Flow Controller

Urban overhead line corridors are becoming increasingly tight,and newly-built UHV lines are basically made of cables.For medium and long-distance cable transmission lines,the equivalent capacitance per unit length is relatively large.It is much larger than the capacitive effect of overhead lines,causing a serious excess of reactive power in the system under light load conditions,which may cause the system node voltage to exceed the limit and endanger the safe and stable operation of the system.In addition,the excess reactive power of the system will move between different plants and between different voltage levels through transformers,which will increase the line loss of the system and affect the economy of system operation.Based on the actual overhead line relocation project of the XA regional power grid,this paper studies the capacitive reactive power surplus problem of the regional cable power grid.First,the impact of long-distance and large-capacity cable access on the operation characteristics of urban ultra-high voltage power grids is studied,and the applicability of using the existing low impedance in the area to compensate the system for reactive power is analyzed;secondly,in order to reduce the use of existing low In order to solve the problem of system reactive power stratification caused by compensation,this paper presents a high-resistance configuration scheme based on an improved multiverse optimization algorithm;finally,in order to solve the problem of low power factor of some lines in XA area,unified power flow control Optimized operation of the grid connected to the power converter.The research results show that after the overhead line is changed to a cable line,the charging power of the XA regional power grid increases to 1199.75MVar,and the bus voltage on the 330kV side of the relevant substation has increased to varying degrees;if low impedance is used for reactive power compensation,a large amount of reactive power will pass The main transformer undergoes hierarchical movement.According to the algorithm proposed in the article,the XA regional power grid is configured with high impedance.The average voltage of each node after compensation is 347.95kV,which is much lower than the 362.98kV without compensation,which meets the requirements of safe and stable operation of the system;the total active power loss of the system is 10.13MW,a reduction of 9.23%,can further improve the economy of system operation.After installing the unified power flow controller,the average power factor of the system increased from 0.8463 to 0.9339;the line with the lowest original power factor of the system increased from 0.2675 to 0.9951;the lowest power factor of the system increased from 0.2675 to 0.7264.The simulation results show that installing a Unified power flow controller is beneficial to the operation of the XA regional power grid.