Shunt Active Power Filter

A shunt active power filter is a device used to eliminate harmonic distortion and compensate reactive power in electrical power systems. It operates by continuously monitoring harmonic components and reactive power in the power system, then providing real-time compensation to improve power quality. The filter typically consists of capacitor banks and electronic switching components (such as IGBTs) that can rapidly respond to harmonic disturbances and reactive power demands. Through sophisticated control algorithms - often implemented using digital signal processors (DSPs) or FPGAs - the device calculates and injects compensating currents that are phase-opposed to the detected harmonics. Key implementation aspects include harmonic detection algorithms (like instantaneous power theory or Fourier analysis), current control techniques (hysteresis control or PWM-based methods), and DC-link voltage regulation. This system effectively reduces harmonic pollution, enhances power factor correction, and improves overall power system efficiency and stability.