| 摘要 |
In fly-back and buck-boost converters (21, 22), to reduce distortions and to increase distortion power factors, arrangements (1) are introduced for adjusting control signals generated by controllers (2) for controlling switches (3) of the converters. The arrangements (1), in response to increased / decreased amplitudes of voltage signals from voltage supplies (4) for feeding the converters, increase / decrease durations of conducting times of the switches (3). This way, unwanted losses in the grid and power generators are avoided. The converters are relatively low cost single stage converters. Preferably, the durations are substantially proportional to sums of the amplitudes of the voltage signals and design parameters. These design parameters may comprise amplitudes of other voltage signals such as output voltages. Arrangements (1) are provided for controllers (2) that can only produce fixed durations as well as for controllers (2) that can produce adaptable durations via adaptable external elements. |
