| Title |
Power Quality Analysis and Failure Survey of Earth Leakage Breakers in Factory Electrical Installation |
| Authors |
Sang-Ick Lee ; Gyu-Ha Choe |
| Keywords |
False tripping; Failure survey; ELB; Power quality measurement; Harmonic |
| Abstract |
This paper proposes the modeling of sensorless drive system using 120 degree conduction method for IPM (Interior Permanent Magnet) BLDC motors and analyzes characteristics of the terminal voltage that is used to detect the rotor position. This paper shows that the ZCP (Zero-Crossing Point) of the measured terminal voltage used in sensorless control is ahead of that of the backEMF of IPM motors because they have a saliency. This research also analyzes that the amount of position detection error is related to saliency, rotor speed, and load condition. In addition, this paper shows that motors have bigger advance angles than we have expected because the ZCP of terminal voltage precedes the actual ZCP, and under operation conditions such as heavy load and high speed it may generate abnormal currents that flow toward opposite direction after phase current becomes zero. |