| Title |
A Study on Development of Open-Phase Protector Having Leakage Current Generation and Incapable Operation Prevention at Open-Phase Accident |
| DOI |
https://doi.org/10.5370/KIEE.2015.64.1.182 |
| Keywords |
Open-phase faults ; Three-phase power system ; Open-phase protector (OPP) ; RCD ; Electrical fire |
| Abstract |
In the three-phase power system, when any one-phase or two-phases is open-phase, the unbalanced current flows and the single-phase power supplies to three-phase loads. Specially, motor coil and transformer coil receive over-current. As a result, great damage as well as electrical fire can occur to the power system. In order to improve these problems, this paper proposes that an open-phase detection device is designed by a new algorithm using electric potential difference between the resultant voltage of neutral point and ground, and a control circuit topology of open-phase protector is composed of highly efficient semiconductor devices. It improves response speed and reliability. The control algorithm circuit also operates the cut-off of a conventional residual current protective device (RCD) which flows an enforced leakage current to ground wire at open-phase accident. Furthermore, time delay circuit is added to prevent the incapable operation of open-phase protector about instantaneous open-phase not open-phase fault. The time delay circuit improves more reliability. |