A line impedance stabilization network for pulse current injection北大核心CSCD

［Objective］Aiming at the deficiency of the existing line impedance stability network (LISN) in the electromagnetic pulse protection capability, a LISN suitable for the pulse current injection (PCI) test of electrical and electronic equipment is proposed. ［Methods］Aiming at the characteristics of high peak value and fast rise of the pulse current in PCI testing, the circuit structure and physical structure of the LISN are improved on the existing basis through PSpice time-domain and frequency-domain simulation combined with engineering design requirements, thereby giving it good nanosecond pulse protection performance and impedance stability at the same time. Pulse current protection performance test and impedance curve test experiments are then designed and carried out.［Results］The experimental results show that the improved LISN can attenuate the injected pulse current by 60 times, while the error of its impedance curve is less than 5% compared with the Type 5 µH LISN in GJB 151B-2013. ［Conclusions］The proposed LISN has good impedance stability and decoupling ability, and can be used in the PCI testing of electrical and electronic equipment in order to protect the power supply and improve the repeatability of testing. © 2023 Chinese Journal of Ship Research. All rights reserved.     

船用变频电缆敷设仿真

为研究船用变频电缆的磁场分布和温升情况,建立变频电缆的二维截面模型,利用有限元软件对在正常工况和缺相运行工况下的周围磁场和热损耗进行仿真计算。磁场仿真结果表明,在不同工况下,变频电缆500 mm远处的低频磁场对船体的磁化作用较小,其磁通密度也不会超过标准规定的人员安全限值。自然对流散热仿真结果表明,系统在缺相故障发生时,非故障相电流升高,变频电缆温度会超过85℃的温度限值,此时电机和供电电缆均需要合理的控制和保护策略,并应该加强通风。     

船舶管路磁信号数值模拟

为研究船舶管路在横摇条件下产生的磁信号,建立大型管路模型,并利用ANSYS有限元软件分别模拟设置电绝缘材料前后的回路电流变化情况.利用得到的电流值作为输入,通过静态磁场仿真定量获得有害磁信号的大小.结果表明,船舶管路在设置高阻材料后,其感应电流大幅减小,大环路产生的有害磁信号也相应减小.     

Numerical method of electromagnetic pulse response of conductor with complex load北大核心CSCD

[Objectives]Electromagnetic pulse can seriously affect and even destroy naval shipborne electronic information systems, weapons, equipment and so on. Due to the complexity of the antenna port load circuit, it is necessary to formulate a numerical method which can easily obtain the antenna load current. [Methods]The induced current of the terminal is obtained on the basis of the finite-difference time-domain (FDTD) and Holland model. According to the Thévenin equivalent circuit, the conductor is equivalent to the voltage source to realize decoupling between the conductor and load end, and the load circuit is solved using Simulink software.[Results]Compared with the traditional terminal model, this method is simple and feasible for high-order circuit processing. The effectiveness of the model is verified using non-linear elements and parallel capacitors and resistors as the load respectively. The results show that the calculation results of this method are consistent with those of the traditional methods. Finally, the antenna of the end-connected protect- or is calculated. The results show that the lead inductance caused by the installation of the protector is an important factor affecting the protection performance.[Conclusions]The method proposed in this paper can greatly reduce the simulation complexity of the coupling current of an antenna with a complex load, giving it useful reference value for the field of ship electromagnetic pulse protection design. © 2023 Editorial Department of Chinese Journal of Ship Research. All Rights Reserved.