Development of super-small floating power supply circuit for current measurement system of high voltage power line

本文研究了一种适用于高压电力线电流测量系统的浮动供电电路。电源规格：输入为3810v /60Hz（配线电压），输出电压为±12V（双直流电压），输出功率0.5W。输出功率由电容器分压器从配电线路电压中获得，而不使用沉重的线圈。在2007财政年度，测量了基本特征，例如(1)负载电阻，(2)配电网电压，(3)配电网频率发生了变化。这些测量结果与hspice模拟结果吻合较好。在2008财政年度，对瞬态响应、热试验和噪声试验进行了验证。首先，对于暂态响应，测量了(1)断电和返回、(2)半周断电和(3)n周断电。失电恢复1.5秒后输出电压达到±12V。由于电路的时间常数长达576ms，即使发生100ms（6个周期）的断电，输出电压也能保持10V以上。接下来，测量温度从-15度到80度变化时的特性。在温度范围内，电容值保持在25nf以上是没有问题的。此外，输出电压的温度依赖性是由所用齐纳二极管的温度特性决定的，测试电路的输出稳压小于±4%。由于所提出的电路不是一种开关调节器，因此不会产生引起问题的噪声。由于目前没有测试设备，未来将测量雷击施加准浪涌电压条件下的特性。

In this research, a floating power supply circuit for current measurement systems of high voltage power line is developed. The specifications for the power supply are that the input is 3, 810V/60Hz (distribution-line voltage), the output voltages are ±12V (dual DC voltages), and the output power is 0.5W. The output power is obtained from distribution-line voltage by a capacitor voltage divider, without using heavy coils.In the 2007 fiscal year, the fundamental characteristics were measured, for example (1) the load-resistances, (2) the distribution-line voltage, and (3) the distribution-line frequency, are changed. These measured results are good agreement with the hspice simulations.In the 2008 fiscal year, the transient responses, the heat tests, and the noise experiments are verified. First, for the transient responses, (1) power failure and return, (2) half-cycle power failure, and (3) n cycles power failure are measured. The output voltages reach ±12V after 1.5 seconds from return of a power failure. Even if a power failure during 100ms (six cycles) occurs, the output voltage can hold more than 10V, since the time constant of the circuit is as long as 576ms.Next, the characteristics are measured when the temperature is changed from -15 to 80 degree. There is no problem when the value of the capacitance can keep 25 nF or more in the temperature range. Moreover, the temperature dependency of the output voltages is determined by the temperature characteristics of the used zener diodes, and the output voltage regulation of the test circuit is less than ±4%. Since the proposed circuit is not kind of a switching regulator, there is no generation of a noise which causes a problem.In future, the characteristics under the conditions that a quasi-surge voltage is applied by thunderbolt will be measured, since there is no test equipment now.