The ground wire is significantly interfered by the current above 1 μA in the industrial field during the traditional polarisation and depolarisation current (PDC) measurement. This paper explains a method to test PDC from high-voltage wire using a principle of equipotential picoammeter, which is completely isolated from the ground wire and connected in series with the high voltage wire. In this method, a device is designed with a multi-range automatic switching function. The device can automatically switch the test range current from 1 pA to 10 mA with a resolution of 1 pA. To demonstrate the device and effectiveness of this new method, the traditional and the proposed new device are used to test the PDC of cable samples in the laboratory as well as in an industrial environment. It is worth noting that there is almost no interference on the Earth wire in the laboratory environment but massive interference in the industrial environment using a traditional method of PDC measurement from ground or Earth wire. The new method of high-voltage testing can efficiently eliminate the interference and accurately measure PDC in a strong industrial interference environment. Furthermore, the wiring of this new method and device is relatively simple, which is convenient for industrial applications.

中文翻译：

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改进极化去极化电流测量方法，避免地线干扰

在传统的极化和去极化电流（PDC）测量过程中，地线受到工业领域1μA以上电流的显着干扰。本文介绍了一种利用等电位皮安计原理从高压线上测试 PDC 的方法，该等电位皮安表与地线完全隔离，并与高压线串联。在该方法中，设计了具有多量程自动切换功能的装置。该设备可以自动将测试范围电流从 1 pA 切换到 10 mA，分辨率为 1 pA。为了证明这种新方法的设备和有效性，传统的和提出的新设备用于在实验室和工业环境中测试电缆样品的 PDC。值得注意的是，在实验室环境中地线几乎没有干扰，但在工业环境中使用传统的 PDC 测量方法从地线或地线测量会产生大量干扰。高压测试新方法可以在强工业干扰环境下有效消除干扰，准确测量PDC。此外，这种新方法和装置的布线相对简单，便于工业应用。