Active DC filter for HVDC system-a test installation in the Konti-Skan DC link at Lindome converter station

An active DC filter installed in the Konti-Skan high-voltage DC (HVDC) link is described. The active DC filter is connected at the bottom of an existing passive DC filter. The active DC filter includes an optic harmonic current measuring unit, a control system, a protection and supervision system, a pulse width modulation (PWM) power amplifier, a high-frequency transformer, surge arrester, and coupling apparatus. The active DC filter is small and occupies little ground area. The performance of the active DC filter for eliminating the disturbing harmonics is excellent.<>