Comparison of Thyristor Rectifier Configurations for a Six-Phase Rotating Brushless Outer Pole PM Exciter
(English)In: IEEE transactions on industrial electronics (1982. Print), ISSN 0278-0046, E-ISSN 1557-9948Article in journal (Refereed) Submitted
Recent technological developments have caused a renewed interest in the brushless excitation system. With the application of wireless communication, the conventional diode bridge is replaced with fully controllable thyristors on the shaft. It offers the same dynamic performance as the conventional static excitation system. The brushless system is also likely to offer reduced regular maintenance. The thyristor bridge of the three-phase PM exciter needs to be controlled with a high firing angle in normal operation in order to fulfill a requirement of a high ceiling voltage and a high ceiling current. A high firing angle causes high torque ripple to be absorbed by the exciter stator and a low power factor results in a low utilization of the designed exciter. In this contribution we present a strategy that solves this problem by looking into combinations of thyristor configurations of a double-star six-phase connection of the exciter. Experimental results are used to verify the circuit models implemented for this investigation. A hybrid mode 12-pulse thyristor bridge configuration seems to be the optimal solution for reducing the steady state torque pulsations and improving the power factor.
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject Engineering Science with specialization in Science of Electricity
IdentifiersURN: urn:nbn:se:uu:diva-317774OAI: oai:DiVA.org:uu-317774DiVA: diva2:1082786