Research On Emulation Technology Of Rail Potential In DC Traction Power System

In DC traction power system,the rail potential and stray current issues are becoming increasingly serious.The existing suppressing measures have difficulties in coordination in field testing,and there are major safety risks.Compared with field test,the hardware test platform is not constrained by space and time,which provides the necessary test environment for the rail potential and stray current suppressing measures.It is of great significance to the application and promotion of relevant suppressing measures.Therefore,this thesis studies the topology and control strategy of rail potential dynamic emulator test platform for DC traction power system.This thesis firstly analyzes the configuration of the DC traction power system and its equivalent circuit model,and studies the simplified method of the distributed parameter circuit model of the reflux system.On this basis,circuit model of the rail potential dynamic emulator test platform system is proposed,and the hardware emulator method of basic units such as the traction substation,catenary,and reflux system that constitute the system are studied.Then,by analyzing the characteristics of the controllable resistance modules of the basic unit,the low resistance converter and the high resistance converter topologies are proposed.Then the operation principles,parameter design and control strategies of these two topologies are studied in detail.Afterwards,both single-section rail potential dynamic emulator system(S-RPDES)and multi-section rail potential dynamic emulator system(M-RPDES)topologies under the bilateral power supply system are proposed.The respective system parameter design,operation modes,and control strategies are then studied.Finally,the simulation model and test platform of Four-section M-RPDES are built.The dynamic emulator of the rail potential under uniform speed conditions and multiple conditions is carried out respectively The simulation and experimental results prove the feasibility of the test platform system topology designed in this thesis.