ns级脉冲磁场传感器的研制

Development of a Nanosecond Plused Magnetic Field Sensor

变电站内存在具有ns级上升沿且幅值较高、频带较宽的快速瞬态电磁脉冲,以辐射和传导的方式干扰保护与控制等二次设备。为了评估变电站内电磁干扰及防护措施对干扰抑制效果的问题,基于法拉第电磁感应定律,研制了一套可用于测量高幅值、宽频带磁脉冲的ns级脉冲磁场传感器,并分析了其基本原理、幅频特性、灵敏度、方波磁场的幅值响应和测量干扰,阐述了其设计原则及应注意的问题。通过模拟电磁脉冲对其标定与测试,结果表明,此传感器的灵敏度为703.42V/T,频带为400kHz～100MHz,满足变电站内瞬态脉冲磁场测量的要求。

The switching operation in the primary circuit will cause the electromagnetic transient process in the high- voltage bus, which produces the transient voltage in the secondary side of the potential transformer and consequently causes the interference in the secondary circuit. All the interferences can cause problems like misoperation, data loss, damage of equipments etc. In order to evaluate the transient electromagnetic interference in substations and to analyze the contributions of shielding measures to the interference, based on Faraday＇s law of electromagnetic induction, we developed a pulsed magnetic field sensor which could be used to measure fast transient magnetic pulses with ns rise time, high amplitude, broadband. The sensor＇ basic principles, amplitude frequency characteristics, sensitivity, amplitude response for square wave magnetic and interference in measurements were analyzed, calibrated and tested by a electromagnetic pulse simulator, and its design approach and problems that should be paid attention to during development were also discussed. The results show that this sensor＂ sensitivity is 703.42 V/T, and its fr quency band is 400 kHz-100 MHz. That is to say it can meet the requirements of measurement of transient pulsed magnetic field in substations.