Abstract

Multiphase machines are often chosen due to their enhanced fault tolerance. Six-phase ones are especially convenient because they may be fed by off-the-shelf three-phase converters. In particular, those with symmetrical windings offer superior postfault capabilities. On the other hand, estimation of the stator resistance is important for purposes such as thermal monitoring and preserving control performance. Resistance estimation by dc-signal injection provides low sensitivity to parameter deviations compared with other techniques. It has previously been shown that the dc signal can be added in the non-torque-producing (<inline-formula><tex-math notation="LaTeX">$x$</tex-math></inline-formula>-<inline-formula><tex-math notation="LaTeX">$y$</tex-math></inline-formula>) plane of a six-phase machine to avoid the torque disturbances that typically arise in three-phase machines. However, extending this method to the case of an open-phase fault (OPF) is not straightforward, because of the associated current restrictions. This paper addresses dc-signal injection in a symmetrical six-phase induction motor with an OPF. It is shown that, in contrast to healthy operation, the postfault dc injection should be carefully performed so that minimum copper loss, peak phase current and zero-sequence braking torque are achieved. A solution that attains optimum performance in all these aspects simultaneously is proposed. Adapted controller and resistance estimation are also presented. Experimental results confirm the theory.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.