| 摘要 |
<p>A multi phase inverter comprising a bridged array of thyristors (1-12) periodically fired in sequence by a source of firing pulses (19, 20) is provided with a circuit arrangement for controlling each extinction angle ( gamma ) of the thyristors individually. Said circuit arrangement comprises means (21) for summing gamma signals, means (30) for differencing said sums to generate an error signal (E1-E5) and means (22) for applying said error signal to said source of firing pulses at appropriate phase angles to appropriate thyristors so as to tend to equalise said sums, the number of pairs of differenced sums being equal to the number of thyristors in the array. Preferably each error signal acts as constant multiplier of a correction signal which is a harmonic of the A.C. output frequency of the inverter. The arrangement improves the efficiency by enabling each gamma to be minimised individually without risk of commutation failure.</p> |
