The structural characteristics and origin of reverse drag anticlines discussed by many authors are reviewed in this paper.

With the Recognition and studies,the structure characteristic is concluded for the Neogene in "Three Harbours" junction area as the following:the structure is a reverse drag anticline controlled by Harbour-west fault,the reservoirs are rich within the structure,similar to the Harbour-east oilfield,it could be a good structure for oil to deposit.

Research purposes: By researching and developing differential current transducer used for leakage detecting,to adapt the ground protection of traction inverter in localization type A metro vehicle.

The detection device,which is applied in the traction inverter and core module on AC trains,is very important and necessary for the vehicle maintenance department.

This article introduces the relevant control and protection of voltage sensors in traction inverters of Shenzhen metro rolling stock,and through contrasting low measured values of voltage sensors,analyzes faults handling of voltage sensors in traction inverters,with the corresponding analysis method and treatment advices for the faults proposed.