ENERGY RECOVERY FILTER WITH VARIABLE QUALITY FACTOR

This paper presents further investigations into using an Energy Recove ry (ER) filter for mitigating harmonic instabilities in integrated ac/ dc system. For certain system conditions a low quality factor (Q) filt er is desirable and for other conditions a high Q is better. This insp ired the concept of a '' controllable Q filter '' in which the power a bsorbed in the filter is controllable by electronic means. The control lable Q filter uses an energy recovery (ER ) link so that this power i s recovered. The investigations are conducted through computer simulat ion using an electromagnetic transient simulation program. The CIGRE b enchmark model is selected as the base system. The results show that t he controllable Q filter helps the system recover from faults.