How to Solve The Problem of Generator Ball Loss of Excitation?

During the use of the generator set, we often find that there is a loss of excitation phenomenon in the brushless motor. The main reason for its demagnetization is firstly caused by long-term idle use, followed by high temperatures. Electric ball carbon brushes are most afraid of high temperatures, and if high temperatures above 150 ℃ occur, there may be demagnetization phenomenon; Another reason is that if the carrier frequency of the frequency converter is very low, it can also cause poor sine wave waveform, leading to an increase in the negative value of ID current and loss of excitation.

After the generator loses excitation, most of it will produce voltage free current output and cause the generator to lose step. This will generate differential frequency current in the damping winding, rotor surface, and rotor winding of the rotor, causing additional temperature rise and possibly causing local high temperature of the rotor, causing serious overheating and endangering rotor safety; Secondly, the synchronous AC generator operates asynchronously, causing pulsating currents in the stator winding, generating alternating mechanical torque, causing vibration of the unit and affecting the safety of the generator. So we must learn to solve the loss of excitation fault of the generator. The solution is as follows:

1. Use a dedicated magnetizer to magnetize the generator rotor (this method is generally applicable to professional power plants).

2. (Recommended method) Use a 12V/24V battery to magnetize the generator rotor. The generator should be turned on slightly below the rated speed. It is preferred to lead two wires from the battery and then touch the excitation terminal of the generator rotor. The positive pole is connected to the positive pole and the negative pole is connected to the negative pole. Touch the two carbon brushes of the rotor for about 20-30 seconds (a small spark indicates the correct wiring direction when touching), and then quickly disconnect the connection between the battery and the carbon brush, Start the diesel generator set.

3. The generator is turned on to the rated speed without grid connection, carrying a certain amount of load, so that the generator is excited and voltage built without the need for manual magnetization.

Due to the gradual improvement of technology and convenience requirements in the current society, most diesel generator sets and generator manufacturers will give up using this low-end generator configuration and instead use self-excited brushless generators. Because the current operating personnel of the unit do not have a basic understanding of the performance of the brush motor, they cannot perform self maintenance after excessive wear of the carbon brush, and suppliers need to solve it.

Jiangsu Starlight Power Generation Equipment Co., Ltd. is an early professional manufacturer of generators and diesel generator sets in China. The company has first-class national-level large-scale production and load testing equipment. Provide users with long-term diesel generator set sales, leasing, technical consultation, commissioning, maintenance, training services and generator set trusteeship business. If you would like to get more information welcome to contact us via sales@dieselgeneratortech.com.