| 摘要 |
A controller (31) for determining the duty-ratio (d) for a pulse width modulator (8) of a converter includes an inner current loop (33), an outer voltage loop (32) and a multiplier (35) with an input voltage feed forward (35.2) to connect both loops. A prediction unit (34) determines a correction signal i cor that is added to the reference current i ref by means of an adder (36) and it further determines a sample correction signal (38) to correct the current samples in the current loop (33). This error-controlled duty-ratio prediction with sample correction results in an improved total harmonic distortion as well as in an improved power factor of the converter. |
