Research On Frequency-Shift-Keying Track Circuit Interference From Neighboring Line And Bypass Circuit

In recent years, with the development of electrified railway, jointless track circuit is widely used in our country. At the same time, to reduce the rail voltage and balance traction current the transverse connection line get used.However, jointless track circuit inevitably produce interference from the adjacent track circuit in the same rail line. And the transverse connection line provide a new way for the interference from neighboring line. If the transverse connection is set unreasonable that may form a "third rail"bypass circuit.In this paper,mainly studies the interference from adjacent track circuit in the jointless track circuit and the influence that transverse connection line may cause. the main work includes the following several aspects.1, establishing the cab receiving model under the shunt state. Simulate and analysis the "runaway" phenomenon caused by poor shunting.Analysis various factors such as the ballast resistance,shunting resistance on the adverse effects of poor shunting, through simulation and calculation,get its worst shunting points. For the interference of adjacent circuit mathematical model is set up, influence on adjacent track circuit interference such as ballast resistance,"a" impedance or "zero impedance tuning unit connection state has carried on the simulation, and get the conclusion that "zero impedance tuning unit play the most important factor than the "a" impedance tuning unit in the adjacent track interference.Analysis transverse connection line’s influence on the neighboring line while the track circuits is unbalanced.2, For the effects of transverse connections to the track circuit,establish a "third rail" bypass circuit model which include transverse connection line, adjacent track circuit and the neighboring line of track circuit.Simulate of "the third rail effect", and analysis interference parameters influence on the circuit such as:ballast resistance signal carrier frequency,length of the bypass circuit,the length of the track circuit, completely broken rail and electrical broken rail.then get the relevant values about the shortest bypass circuit.3,Field test for the interference from neighboring line (and adjacent track circuit) and the’third rail’effects.analyses the test data,and compare it with theoretical analysis,then get the conclusion that transverse connection line is a path of neighboring line interference,also a part of the bypass circuit.And its influence on the track circuit is inevitable.So the transverse connection line need properly set. 4,Study on the track circuit interference from the traction current.Analysis the interference of the unbalanced current, impulse noise,and the traction return current on the track circuit.track unbalanced is basic reason of the traction current interference;impulse noise is the main interference form to the track circuit;the traction return current need to properly design, at the same time bypass circuit should also be avoid.