信号发生装置中应用

鉴于S注入法在高阻接地时易于受到分布电容的影响,提出对基于S注入法的信号发生装置的研究,介绍了信号源的硬件结构和软件设计。硬件控制部分采用了单片机控制脉冲调制,分析了脉冲宽度调制(PWM)控制技术在该装置中的应用;软件设计根据所需的注入信号与PWM波的关系,通过软件编程得到PWM信号。高频的PWM信号激励逆变电源中2个开关管,输出端通过滤波得到具有很高稳定性的注入信号,产生频率恒定、电压可调的交流信号,使得信号探测器很容易探测到该信号。该信号源装置降低了高阻接地探测的难度,使故障定位的精度和可靠性都得到大幅提高。

MCU-controlled PWM in signal generator for S's signal injection method

Considering the influence of distributed capacitance on S's signal injection method for high-resistance grounding faults,a further research of the signal generator for S's signal injection method is carried out and its hardware and software designs are introduced.MCU-controlled PWM(Pulse-Width Modulation)is adopted in hardware design and its application is analyzed.In software design,PWM signal is got by software programming according to the relationship between the required injecting signal and PWM wave.The high-frequency PWM signals control the two switching thyristors of inverter and the output injecting AC signals,after filtering,are of steady frequency and adjustable voltage,which makes detection easier.The difficulty of high-resistance grounding fault locating is thus reduced,and its precision and reliability are greatly improved.