Research On Fault Location For Double Circuit Overhead Lines On Same Tower

Because of sharing the same towers,the double-circuit overhead lines on same towers have the notable economic benefit,this technology has been used widely in the pwer system.This paper presents deeply the peculiar problem of protection for the double-circuit overhead lines on same towers at first,then proposes the fault location methods for these lines:1) By using the positive and negative sequence components of voltage and current synchronously sampled at both terminals,a fault locating method for any fault types can be got from uniform transmission line equations.Because there is no need for acquiring the zero-sequence component,this principle can eliminate the effect of zero-sequence mutual inductance between coupling lines.Simulations show that the proposed fault location method has a satisfactory precision.2) Proposing a fault location method for the double-circuit overhead lines on same towers based on two-end unsynchronized measurements.With this method it needs to estimate the unknown fault distance and synchronization angle under the condition of lumped line model at first, then takes the estimating result into the iterative calculations which are deduced from transmission line equation,the optimization result can be get.