Study On The Electrical Characteristic And Engineering Application Of The220kV Multi-Tower Transmission Line

The strong growth of China’s electricity load and the process of urbanization isaccelerating, the high voltage line construction and local land-use planning has becomeincreasingly prominent contradiction. The same tower back transmission technology in thesame tower and twin back even multi-circuit transmission lines, thereby compressing the areaof the line corridor covers and improving the transmission capacity of the unit corridor of newtransmission technology.With the same tower back line increasing，in the regional power grida large number of short and even ultrashort220kV with the rod of Multi-circuit Transmissionlines,but but they generally use transposition erection. in recent years three-phase imbalancecaused by non-transposition of the same rod back line become increasingly prominent, theimbalance of power system current, voltage, three-phase system is running negative sequenceand zero-sequence component will bring a lot of negative phenomena of electricity systemand the user has great harm.. At the same time, Multi-circuit lines on the same towermaintenance, the size of the blackout line of inducing of voltage and current can not beignored, may harm staff overhaul, in order to ensure the reliability and security of the running,it is necessary to carry out the calculation, to select the appropriate earthing switch with theopening and closing of the induction current.In this paper, the multi-circuit transmission lines on the same tower, on the basis ofprevious studies, using PSCAD/EMTDC electromagnetic transient program detailedcalculation of220kV West-now-delta side project with tower of four lines of three-phaseunbalance, and induction current and voltage, it is necessary to calculate, selection the righthas a switching induced current grounding switch. the main job is as follows:First, the basic parameters of this article220kV Xijiang-Guangxiao-Zhoubian PowerTransmission Engineering, established based on PSCAD the mathematical model of thesimulation,to prepare for the following of the simulation work.Second, according to the National Institute of Standards and related documentsindicators, pointed out the limits of the three-phase unbalance their formula, Calculated in thebasic form of a three-phase unbalance and explore its influencing factors, and pointed out thatthe suitable wire arrangement of the project. Third, theoretically analysis the calculation of the inducted voltage and current, the sizeof the induced voltage and current are calculated at the different operating conditions, theanalysis of different factors on the current role of the induced voltage, the calculation resultwill line maintenance personnel safety and selected with the opening and closing of theinduction current capability of the grounding switch to provide guidance.Finally, according to the summary of the work done in this article, proposed theengineering220kV Xijiang-Guangxiao-Zhoubian of Power Transmission suitable wirearrangement sequence and other attention problems.