when line commutated converters are used, the converter station will require between 40% and 60% of its power rating as reactive power. this can be provided by banks of switched capacitors or by synchronous condensers, or if a suitable power generating station is located close to the static inverter plant, the generators in the power station. the demand for reactive power can be reduced if the converter transformers have on-load tap changers with a sufficient range of taps for ac voltage control. some of the reactive power requirement can be supplied in the harmonic filter components.