This series of tuning reactors are used in low-voltage reactive power compensation cabinets and are connected in series with capacitors. When there are a large number of harmonic sources such as rectifiers and converters in the low-voltage power grid, the high-order harmonics generated will seriously harm the main transformer and other electrical appliances. Safe operation of equipment. After the reactor is connected in series with the capacitor, it can effectively absorb the harmonics of the grid, improve the voltage waveform of the system, improve the power factor of the system, and can effectively suppress the closing inrush current and operating overvoltage, and effectively protect the capacitor.