HARMONIC NEUTRALIZED VOLTAGE SOURCED INVERTER EMPLOYING PHASE SHIFTING INTERPHASE TRANSFORMERS

摘要

Sets of phase shifting interphase transformers are used to combine the outputs of six-pulse static inverter stages to generate harmonic neutralized outputs with higher pulse counts. The phase shifting interphase transformers have a primary winding and at least one secondary winding. For phase shifting interphase transformers having a single secondary winding, a tap on the primary winding is connected through the secondary windings on one of the other phase shifting interphase transformers to produce a combined output having a displacement factor which preserves the displacement factors of the inputs. When the phase shifting interphase transformer has two secondary windings, the tap on the primary is a center tap which is routed through secondary windings on each of the other two phases. Higher pulse count inverters are constructed by combining outputs of the phase shifting interphase transformers with additional shifting interface transformers to generate a combined output. For inverters with an odd number of six-pulse inverter bridges, a hierarchy of phase shifting interphase transformers produces a single 'pairs' output which is in phase with and combined with the output of the remaining inverter stage by a current splitting interphase transformer to produce the final, harmonic neutralized output.