Research on the influence of the connection and withdrawal of a 35 kV bypass system on the power quality of transmission lines

Abstract

Uninterrupted power supply maintenance has become a trending issue with the increasing reliability requirements for 35 kV power transmission. The bypass operation holds significant importance in 10 kV and 100 kV power transmission maintenance. However, research on live maintenance of a 35 kV bypass system remains scarce and requires urgent supplementation. Therefore, this paper aims to determine the feasibility of live operation for the 35 kV bypass system by studying the impact of its connection and disconnection on the voltage and current of the transmission lines. The existing 35 kV bypass live maintenance system is analyzed and studied concerning the operational process. When the bypass system is connected or disconnected during the maintenance of transmission lines, it may cause changes in the voltage and current, which could affect the safety of power transmission. To address this phenomenon, the paper performs calculations and analysis for different scenarios, including moments of varying voltage amplitudes in the lines and different maintenance cable lengths in the bypass system. Through theoretical analysis and simulation, a comprehensive study of voltage and current variations in two different scenarios of transmission lines has been conducted during the simulation process, including equivalent capacitance and initial conditions for the transmission lines and bypass systems, enabling the simulation of the switching process. Based on calculations and analysis, this paper presents a safety assessment of live operation in the 35 kV bypass live maintenance system.