STB series intelligent harmonic suppression integrated power capacitor compensation device (hereinafter referred to as intelligent suppression capacitor) is composed of intelligent measurement and control unit, synchronous zero switching switch, intelligent protection unit, networking unit, display unit, two (△ type) or An intelligent reactive power compensation system composed of one (three sets of Y-type) pure dry-type high-quality filter power capacitors and high-quality copper reactors. The product has the characteristics of modularization, standardization and maintenance-free, and has the functions of zero switching, graded compensation, over-current/over-voltage/over-temperature protection, fault self-diagnosis, measurement, communication, signal, online and other functions. STB series intelligent harmonic suppression capacitors are used in low-voltage power systems with serious harmonic content in the power grid. They can operate safely and reliably without generating harmonics. They have no amplification effect on harmonics, and have the function of absorbing harmonics to a certain extent. It effectively improves the power factor of the system, reduces the line loss, and improves the power quality of the power grid.