直流特高压环境下数据采集系统的电磁防护技术

Electromagnetic Protection Technology of Data Acquisition System in UHVDC Environment

安装在特高压直流线路高压侧的宽频域电晕电流在线测量系统处于直流特高压电磁环境中。为保证其正常工作时的稳定性以及测量数据的有效性,利用电磁屏蔽理论计算和ANSYS仿真相结合的方法研究了该系统在直流特高压环境下的电磁屏蔽效能。计算结果表明,该系统在100MHz时的屏蔽效能可达73dB。将该系统应用于实际工程中并采用紫外成像仪图像观测其表面,发现测量装置图像中的光子数为0,即表面无放电。研究结果表明,该电晕电流在线测量系统的屏蔽方案可行,防护效果良好,能保证系统在直流特高压环境下正常工作。

Wide-frequency online measurement system of corona current installed in the ultra high-voltage direct current（UHVDC] test lines in China works in UHVDC electromagnetic environment. In order to ensure that the system works stably and obtains valid data, we discussed the shielding effect of corona current online measurement system in UHVDC environment on the basis of the electromagnetic shielding theory and modeling in ANSYS. Simulative results indicated that the system had shielding effectiveness of 73 dB at 100 MHz. The measurement system was applied in an actual project, and its setup was observed by ultraviolet imager. The photon number of the ultraviolet setup images was 0, meaning that no discharge appeared on the equipment surface. It is concluded that the proposed measurement system has an effective electromagnetic protection, and it can work normally and efficiently in UHVDC environment.