Abstract: The tuning zone of ZPW-2000A jointless track circuit is composed of type 1 tuning unit, rail, air core coil, and type 2 tuning unit. The tuning unit to which the section is connected is capacitive, and the tuning unit to which the adjacent section is connected with the rails and air core coils is inductive. The two parts form a parallel resonance. This paper analyzes the influence of the SVA impedance value of the ZPW-2000A air core coil on the whole resonant circuit, and proposes a method for calculating the quality factor of the small rail circuit in the tuning zone. By improving the quality factor of the tuning zone, the stability of the rail transmission can be improved and the frequency selection performance of the tuning zone can be enhanced.

Key words: jointless track circuit, air core coil, tuning zone, quality factor

摘要： ZPW-2000A无绝缘轨道电路调谐区由1型调谐单元、钢轨、空心线圈、2型调谐单元构成，本区段所连接的调谐单元显容性，钢轨、空心线圈和邻区段连接的调谐单元呈感性，这两部分形成并联谐振。分析普速铁路ZPW-2000A空心线圈SVA阻抗值对整体谐振电路的影响，提出调谐区小轨道电路品质因数的计算方法，通过提高调谐区品质因数，可以改善钢轨传输的稳定性，增强调谐区选频性能。

关键词: 无绝缘轨道电路, 空心线圈, 调谐区, 品质因数