Unbalanced Voltages of Bow Thruster Motor Performance in the Ship Using Simulation

The performance of the bow thruster motor depends on the quality of the supplied voltage and the voltage coming out of the motor. Under unbalanced voltage situation, it will cause the poor performance of the motor. The latest regulation of International Convention for the Prevention of Pollution from Ships (MARPOL) requires that the ship's electrical system under the dynamic positioning operating mode, should be operated with a closed bus configuration. Under such configuration, motor thrusters is prone to the of electrical components failure such as harmonics. In this study, the investigation has been performed using MATLAB in order to see the effect of six voltage imbalance conditions occurring in the vessel on bow thruster motor performance with variation of voltage imbalance factor based on true definition of IEC. The resulted analysis has shown that there are various detrimental impacts resulted from different condition of imbalance of voltage. In the imbalance factor 5% condition undervoltage 3 phase has the smallest output power 22321.59 watt with the smallest torque 142.9039 Nm, but it has a power factor 0.762326 which is still allowed by rule of IEC.