Transient earth voltage (TEV) detection is one of common methods to measure the partial discharge in switchgear cabinet. However

the TEV signal interference frequently arises between equipment due to the layout of the earthing system at site

thus making it difficult to locate the discharge source. In view of this issue

the electromagnetic simulation models of the single switchgear cabinet and side-by-side switchgear cabinet of switch room of substation are constructed respectively to study the the optimal measurement point of TEV in case of unknown partial discharge source and the the location method for partial discharge in case of sharing the earthing system by the multiple switchgear cabinets. It is shown by the simulation result that in case of unknown partial discharge source the measuring point at the lower center of the front of the switchgear cabinet has the optimal measurement effect. As for the side-by-side switchgear cabinet with a common earthing system

the response amplitude of the same discharge pulse of each switchgear cabinet is attenuated significantly with the increase of distance of its partial discharge source. Therefore

the location of the partial discharge source can be achieved by constructing distributed sensor network under the simultaneous detection condition. Finally

the actual measurement performed at site of certain substation shows that the distributed simultaneous measurement method has good application effect and has provided valuable reference for the site application of TEV.