| Title |
Stability Evaluation of Series and Parallel Varistor Combination Using Thermal Image Analysis |
| Authors |
Ju-Hong Eom ; Sung-Cheol Cho ; Tae-Hyung Lee ; Hoo-Sek Han |
| Keywords |
Varistor ; SPD ; Residual voltage ; Leakage current ; Thermal image |
| Abstract |
According to the recent revision of KS on the basis of the IEC, equipotential grounding systems has been come into focus and the use of surge protective devices (SPD) has been increased radically in order to operate the power system stably. ZnO varistor with non-linear resistance, which has an outstanding voltage-current(V-Ⅰ) characteristic, is mainly used in power system to limit surge voltage and divert surge current. ZnO varistors are packaged several types based on the circuit assembly to be connected to a.c. power line. When the user assemble the ZnO varistors into parallel or series circuit package, there are many things to be taken into consideration including functions and thermal stability because they are directly related to the safety. We compare stabilities of each assembly type by measuring residual voltage, discharge current, leakage current and surface temperature concerned to the protection performances between a single device with a 40[kA] of current capacity and parallel or series circuits type of varistor package. |