Influence of Single-Phase Voltage Loss and Load Carrying Mode on Mine Drainage Pump Motor in Vietnam

Abstrakt

Mine drainage pump is the most important load in mining which requires high reliability
when operating. Currently, the power supply of a mine drainage pump is connected to the same power
line with many nonlinear loads, and is equipped with power electronic converters, which makes the
power supply nonsinusoidal. During the working process of a mine drainage pump, the load-carrying
factor often changes, and many types of failures occur, among which single-phase voltage loss is the
most common problem. In the case of a nonsinusoidal power supply, if a single-phase voltage loss
occurs in different load modes, it will greatly affect the working mode of the mine drainage pump
leading to influences on the working efficiency, the life of the pump, and sometimes it is necessary to
recalculate the protection parameters. This paper studies the influence of single-phase voltage loss and
load carrying mode on the working mode of mine drainage pump motor in case the of nonsinusoidal
power supply. Research results show that, in the case of nonsinusoidal power supplied with single-phase
voltage loss, copper losses in the rotor and stator circuits increase with increases in voltage total
harmonic distortion (THD) and load-carrying factor, 5th order reverse harmonic increases copper loss in
asynchronous motor the most, and higher harmonic components have less effect on copper loss in the
motor. At the same time, the speed ripple decreases with the increase of the motor load factor and
decreases in the presence of the 5th order negative sequence harmonic, and increases significantly in the
presence of the 7th order positive sequence harmonic. 5th order negative sequence harmonic increases,
the torque ripple increases, while the 7th order positive sequence harmonic reduces the torque ripple in
the case of single-phase voltage loss. The results of the paper will help improve the operational
efficiency of the mine drainage pump in Vietnam's mines.