| 摘要 |
An electrical generating system for aircraft with one or more engines (1,1a) includes a plurality of generators (13,23;33,43) associated with the engines so as to produce respective AC outputs. The frequencies of these outputs can differ from each other, as a result of differing engine speeds and/or deliberate design, but they are to be connected to a common bus (50) to avoid redundancy of wiring. To this end, one or more converters (10,20;30,40) are present between the generators and the bus for adjusting the output frequency of the generators to provide an AC output voltage at a common bus frequency f B . Normally this would necessitate large converters to cope with the large range of speeds. However, the invention contemplates a control system (17 ... 47, 60) for setting the AC bus frequency f B in such a way that it can vary with time; since in normal situations the generators will be running at fairly close frequencies, even if the absolute value varies widely, the bus frequency can be allowed to follow the natural frequency of the engine, and only small converters (10-40) are needed to make the already approximately equal generator frequencies identical, so that they can all feed the common bus. |
