An ICPT-Supercapacitor Hybrid System for Surge-Free Power Transfer

This paper presents a technique for the suppression of voltage transients through the use of dynamically reconfigurable supercapacitor (SC) banks. The technique requires a minimum of two SC banks to transfer power from a mains supply to load in complete isolation. The banks are operated independently as energy-storing elements in one of the three states of charging, discharging, or idling, and transition of banks from one state to another with isolation is realized dynamically by inductively coupled power-transfer technology with no physical contacts. The proposed technique has no direct connection between the mains supply and load at any given moment, and power transfer takes place in complete isolation with built-in protection for both common- and differential-mode transients. Sizing of the banks with respect to various types of SCs and system parameters is analyzed. Comparisons between simulations and experimental results of two prototype systems, subjected to combination transient surges specified by IEC61000-4-5 standard, are presented with a discussion to show the validity of the proposed concept and its suitability for uninterruptible power systems and emergency power supplies.