抄録
The author propose two types of harmonic reducing 3-phase-bridge diode-rectifiers consisting of single or double parallel conventional 3-phase-bridge diode-rectifier of capacitor-input type and an auxiliary circuit. In double 3-phase-bridge type, harmonics of the total input current are remarkably reduced by connecting the midpoint on dc-side to the neutral point on the 3-phase ac input side. The midpoint on dc-side is provided by using two dc-capacitors connected in series between upper and lower dc-rail, while the neutral point is provided by using zigzag auto-transformer if isolation between the ac-side and the dc-side is not necessary and a delta-star isolation transformer is not available. In single 3-phase-bridge type, the harmonic reducing principle in the double-bridge type is applied by adding low rating diodes to the auxiliary circuit. Since both the proposed harmonic reducing rectifiers do not require a self-turn-off device nor a controller, the proposed diode rectifiers are very economical, efficient and reliable. Therefore, the new rectifiers of single-bridge type and double-bridge type are suitable for low to medium and medium to high power applications, respectively.
This paper describes the unique arrangement and the particular operation of the proposed rectifiers and then, the performance is evaluated through simulation results for double-bridge type and a experimental results for single-bridge type.
