| 摘要 |
<p>A method or apparatus for detecting a missing phase or an input supply drop in a 3-phase twelve-pulse autotransformer rectifier unit (ATRU) monitors the frequency and amplitude of a common-mode voltage impressed on the rectifiers DC output. A phase-loss indication may include a frequency drop in the common-mode voltage to below a predetermined threshold, or an amplitude increase in the common-mode voltage to above a preset threshold. Frequency or amplitude detection may be carried out using either a digital or an analogue circuit. The common mode voltage may be detected relative to the generator neutral voltage. The method or apparatus may be suitable for use in an aircraft power supply system.</p> |
