| 摘要 |
<p>CAPACITOR STRUCTURES WITH IMPROVED ELECTRICAL STRESS CAPABILITY Power capacitors with a wide electrode and a narrow electrode and a composite dielectric including a first portion adjacent the narrower electrode that is of higher dielectric constant and/or lower resistivity than the portion adjacent the wider electrode. The first portion may be a porous material whose impregnation with a suitably chosen dielectric fluid results in the desired electrical properties. In such structures the narrower electrode preferably has rounded and smooth edges such as by folding. The wide and narrow electrodes may each comprise one of the externally connected capacitor electrodes. Alternatively, the wider electrode may be electrically floating and arranged between dielectrics and a second narrower electrode in a symmetrical arrangement with the two narrower electrodes serving as the externally cconnected capacitor electrodes. In structures as described, in which the narrower electrodes have rounded and smooth edges, further benefit is obtained by using normal aluminum foil material for electrodes and folding each edge substantially to the center line of the foil with the surface having a mat finish disposed on the outside of the folds. In structures as described in which the wider electrode is electrically floating, it may be a separate foil element or may be a metallized layer deposited on one of the adjacent dielectric sheets. Also the floating conductor may be a single continuous layer or may be of two bands each of which encompasses one of the edges of the narrower electrodes.</p> |
