| 摘要 |
The buck cell to be protected has a switching transistor (17) which is normally conductively connected during each variable period interval (T) for a constant connection interval (t). The necessary control system comprises, in a manner known per se, a nonstable multivibrator (25), a regulator (27) and a voltage frequency transformer (33). The control system is overridden by an emergency control (28) which intervenes in the control process through a priority circuit immediately the current through the switching circuit tends to become too high. The emergency control system constitutes a predictor control which makes its predictions for each subsequent period interval (T) on the basis of a knowledge of the mode of operation of the buck cell and the instantaneous input voltage (e) and output voltage (Uist) of the buck cell and the current (iL) through the storage choke of the buck cell. The emergency control (28) therefore reacts very rapidly. |
