サイクロコンバータの駆動法の研究 II

概要

論文の詳細を見る
Microcomputers are often applied to control power electronics devices. Recentely, to digitally control a cycloconverter, they have been used to calculate firing angls of thyristors and to operate counters. When the counter reaches the firing angle value, the computer emits a pulse to the definite thyristor. In general, the same number of counters as thyristors, as well as six different firing angles have been used. (A-phase positive, negative, B-phase positive, negative, C-phase positive and negative group) The cycloconverter under discussion requires only three kinds of firing angle data and only six counters. Because positive and negative data for firing angles in each phase are the same only one counter is necessary for each group. In the positive group, a down-counter is employed, and in the negative group an up-counter is employed. The counters operate one by one with PLL (phase locked loop) which divides 3600 sections between two cross points of phase voltage. Following are the advantages of using this controller. 1) The controller and its hardware are simpler than usual. 2) Operation is accurate. 3) Size of controller is precise. 4) Manufacturing cost is lower.