Saifu brand metallized film capacitor can be charged for a long time, and discharged in a very short time, thus forming a huge pulse power. The pulse power is obtained by the charged pulse capacitor bank, obtained by the short-term oscillation discharge of the main reactor, while the pulse capacitor bank is charged by a low-power charging device before the test, and it takes a long time to charge, and the oscillation discharge is only tens of milliseconds, thus greatly improving the test power and The ratio of power supply to power improves economic efficiency.