中文摘要：

基于接触线的振动微分方程，得到弓网离线时放电电弧等效电路时变电阻和时变电感与动车组速度的关系，在此基础上结合动车组牵引供电系统等效电路，建立动车组弓网离线放电电磁骚扰源模型。通过Matlab／Simulink仿真软件得到不同傅里叶级数下弓网离线时动车组车体馈电端骚扰电压的仿真波形，并与实测结果对比。结果表明：取傅里叶级数大于4即可保证仿真的准确性，验证了模型的正确性；弓网离线产生的骚扰电压呈周期性变化，动车组的速度越高，骚扰电压的变化周期越短，而放电频率和骚扰电压幅值越大，骚扰电压与动车组速度为指数函数关系。

英文摘要：

Based on the vibration differential equations of contact line, the relationship between the time- varying resistance ~ time-varying inductance of the equivalent circuit of electrical discharge arc and EMU speed upon pantograph-catenary disconnection was obtained. Based on this, the electromagnetic disturb- ance source model of discharge upon pantograph-catenary disconnection was built combining the equivalent circuit of EMU tractive power supply system. The simulation software of Matlab/Simulink was used to obtain the simulation waveform of the disturbance voltage at the feed end of EMU carbody upon panto- graph-catenary disconnection in different Fourier series, and was compared with the measured result. It is clear that the accuracy of simulation can be ensured when the Fourier series is greater than 4, and the cor- rectness of the model has been validated. The disturbance voltage caused by pantograph-catenary discon- nection changes periodically. When the speed of EMU is higher, the change period of the disturbance volt- age is shorter while discharge frequency and the amplitude of disturbance voltage are greater. The relation- ship between disturbance voltage and the speed of EMU is exDonential functicm