Steady state modeling and loss suppression of urban transmission system based on improved multi conductor theory

Aiming at the problems of high grounding loss and sheath current risk in urban underground power transmission system, an improved multi-conductor modeling and intelligent impedance compensation strategy are proposed. In the modeling aspect, the transmission line is discretized into micro-element segments, and the node admittance matrix is constructed based on telegrapher's equation, and the matrix-level cascade algorithm with grounding nodes is introduced to solve the problem of diagonalization failure of the conventional propagation matrix in the of repeated eigenvalues, and the high-precision solution of the voltage and current distribution in the whole system is realized. The simulation results show that the proposed method can control the calculation error sheath induced voltage and circulating current within 1%, and provide technical support for real-time optimization and intelligent control in the operation and maintenance of power transmission system.