Does a diesel generator set produce shaft voltage?

Recently, some customers have become interested in the shaft voltage of diesel generator sets. In this regard, Haixing will give you a comprehensive introduction to what shaft voltage is and why the generator set generates shaft voltage, so as to deepen your understanding of it.Generator setunderstanding.

Shaft voltage refers to the voltage generated between the two bearing ends of the motor or between the motor shaft and the bearings when the generator is running. The generator shaft voltage always exists, but it is generally not high. However, when the insulating pad is oily, damaged or aged, etc. When it loses its function, the shaft voltage is enough to break down the oil film between the shaft and the bearing and discharge occurs. Over time, the quality of the lubricating and cooling oil will gradually deteriorate. In severe cases, the rotating shaft and bearing bushes will be burned out, causing shutdown accidents.

Why does the generator set generate shaft voltage? This is due to the unbalanced magnetic field of the stator of the generator, which generates an induced electromotive force on the rotating shaft of the generator. The reason for the unbalanced magnetic field is generally due to the large local magnetic resistance of the stator core (such as corrosion of the stator core) and the uneven air gap between the stator and the rotor.

In order to prevent damage caused by shaft voltage, Haixing recommends using polyester glass laminates to make insulating plates at the bearing ring at the excitation end and the oil sealing device used to prevent hydrogen leakage. The insulating plate has insulation resistance measurement leads lead out of the machine. When installing and operating the generator set, it is also necessary to measure and check the voltage between the shaft and bearings of the generator set to ensure that it is within the normal range and does not affect the operation of the unit.