General common problems of synchronous generator processing

General common problems of synchronous generator processing

The synchronous generator is directly connected with the load, the voltage is high, the current is large, and sometimes there will be some problems in the long-term operation.

(1) The diesel engine works normally, but the generator does not produce electricity or the voltage emitted is very low

This may be due to parts associated with the generator, such as the exciter being damaged and unable to provide excitation voltage. The rotating rectifier is faulty and cannot inject excitation current into the rotor winding. The remanence of the rotor core weakens or disappears. Will make the generator can not produce power or output voltage is very low.

The means of response are generally: select the appropriate DC voltage and according to the polarity, directly connected to the excitation winding magnetization. Check exciter and rotary rectifier carefully, find faulty components or windings, replace and repair them.

(2) The output voltage of the generator is unstable, and with a large load, the output voltage drops very badly

General automatic voltage regulator (AVR), excitation generator and rotary rectifier failure, is the main reason for this phenomenon. The failure of the negative feedback adjustment function of AVR for voltage or load change, the damage of some components of the rotary rectifier and the voltage setting circuit of the excitation generator, etc., which aspects of the problem will cause the output voltage instability.

The measures to be taken are: focus on detecting AVR, using the simulation experiment method to check whether its sensitivity and output linearity meet the factory standard, and if there is a problem, it will be repaired. There are not many components of rotary rectifier and excitation generator related circuits, and the objects of inspection are mainly rectifier components and potentiometers. Replace if damaged.

(3) The temperature of the body rises fast and the vibration is large during operation

This problem is mostly due to the short circuit between turns of the excitation winding coil or the load seriously exceeding the rated value, which increases the excitation current and causes the rotor to heat. The change of the gap between the rotor and the stator of the generator causes part of the generator to touch the sweep chamber, which makes the body temperature rise rapidly.

According to these conditions, it is necessary to check the front of the rotor shaft and the rear of the elastic coupling and the bearing for loosening and damage of parts. And replace the old with the new. The short circuit between turns of rotor winding should be re-wound with insulating wax silk. The total active power and reactive power of the load should be carefully calculated and reasonably configured so that they do not exceed the rated value of the generator.