Fault Path Direct-Current Resistance Based Off-Line Single-Phase-To-Ground Fault Location

Abstract

In order to figure out the off-line transmission line fault location, a new fault location method based on fault path direct current resistance measurement is proposed. Firstly, an off-line fault detection and diagnosis method based on three-phase insulation resistance measurement is proposed, including fault type and fault phase diagnosis. Then the single-phase-to-ground fault location method is proposed which occurred the most frequently. In the proposed methods, the ground resistance and three phase direct-current resistance between two substations are measured firstly. Then considering the effect of fault resistance, the KVL is used to form two independent equations which contain two unknown numbers, fault resistance and fault distance. Then fault distance and fault resistance can be figured out by solving equation set. The proposed method is verified in the PSCAD/EMTDC by simulation. The correctness and accuracy of the proposed fault location method are verified. Also it is verified in the field test. It is helpful for clearing the fault for newly-built lines and overhaul lines. It is very important to ensure that transmission lines are put into operation on time.

Keywords

• direct-current resistance
• fault location
• transmission line
• off-line: fault diagnosis