Low Voltage (LV) and High Voltage (HV) passive harmonic filters are used to mitigate harmonic distortion in electrical power systems. The filters are designed ti mitigate harmonics to meet IEEE519 STDs.
It is a known fact that active harmonic filters are not real filters, since those do not protect internal devices from being damaged due to harmonics. Whereas, passive harmonic filters really filter out harmonics making those really suitable to meet consumer needs.