| 摘要 |
<p>Provided are a method and device for measuring impedance between the live wire and earth wire of a power supply, the method comprising: acquiring live wire-to-neutral wire impedance RLN, neutral wire-to-earth wire impedance RNE, and neutral wire impedance RN; and using a formula to acquire live wire-to-earth wire impedance, that is, RLE=RLN+RNE-2RN, such that RLE is obtained by measuring RLN, RNE and RN. Because a civil power frequency power supply has three ports: a live wire port, a neutral wire port and an earth wire port, and an RCD protector is installed in the circuits of the ports, so heavy current measurement cannot be directly conducted on the three ports; instead, using a different means to indirectly measure the three ports so as to obtain the impedance values RLN, RNE and RN, and obtaining a loop impedance RLE value through calculation. The present invention obtains loop impedance between a live wire and an earth wire by simply changing the measurement method, thus being simple and reliable, and prevents all RCD protectors from functioning (tripping).</p> |
