S型电气绝缘节的建模与分析

Modeling and analysis of S-shaped electrical sectionalizing joints

S型电气绝缘节是一个小参数和分布参数电路,为了分析S型绝缘节对无绝缘轨道电路中信号传输的影响,运用电路理论的支路电流法讨论了其数学模型的建立与仿真算法的实现,给出了绝缘节的输入阻抗、电压传输和电压隔离特性曲线,并分析了绝缘节的选频能力以及在绝缘节内分路时对轨道电路接收性能的影响。其各种数字仿真结果与实物测试结果具有相近的变化趋势。结果表明:S型绝缘节具有良好的选频性,且在S型电气隔离区段内无死区段,但有分路重迭区段。

S-shaped electrical sectionalizing joints are circuits with small, distributed parameters. The electrical characteristics of an S-shaped joint in a jointless track circuit were analyzed using the branch current method of circuit theory. The analysis gives several characteristic curves of the S-shaped joint, such as the input impedance, the voltage transfer, and the voltage isolation performance. The analysis also describes the joint's capability for distinguishing different frequencies and its influences on the reception of the track circuit in the joint zone shunt. The simulation results agree well with actual measurements. The results show that the S-shaped joint provides good frequency selection with no dead zone, but with a shunt zone overlap.