The high potential board plays an important role in the SVC, converting the received light trigger signal into an electrical signal and triggering the thyristor, and the voltage of the high potential board is the same as the voltage of the directly connected bus voltage. Therefore, the high potential board is taken. Can be especially important. The energy-receiving method has high-potential energy-receiving, mainly in the thyristor RC absorption capacitor. This method has a certain dependence, and is subject to the operation of the equipment; in addition, the isolation transformer is used for energy extraction. This method is also not desirable, the transformer production requirements are high; there is also a high-frequency current loop for energy extraction, which can achieve high-voltage and low-voltage isolation, and is not affected by other equipment. This technology belongs to Baoding City. The patented products of Electric Co., Ltd. provide guarantee for the reliability of SVC.