Why The Diesel Generator Sets Do Not Generation Part 2

In this article, we will continue to introduce why the diesel generator no generation, if you still any question on the point, welcome to visit our Starlight website.

1. Excessive current of diesel generator set

(1) If the load is too large, the load should be reduced.

(2) In the event of a phase-to-phase short circuit or ground fault on the transmission line, the line should be overhauled, and the fault can be restored to normal.

2. The terminal voltage of the diesel generator set is too high

(1) The voltage of the diesel generator set parallel to the power grid is too high, and the voltage of the parallel diesel generator set should be reduced.

(2) Excitation device should be inspected and repaired in time due to overexcitation caused by failure of excitation device.

3. Insufficient power

Due to insufficient compound excitation compensation of the voltage source of the excitation device, the excitation current required for armature reaction cannot be provided, and the terminal voltage of the diesel generator set is lower than the grid voltage, and the rated reactive power cannot be delivered. The following measures should be taken:

(1) A three-phase voltage regulator is connected between the diesel generator set and the excitation reactor to increase the terminal voltage of the diesel generator set, so that the magnetic potential of the excitation device gradually increases.

(2) Change the phase of the voltage magnetomotive force of the excitation device and the terminal voltage of the diesel generator set to increase the combined total magnetomotive force. A resistance of several thousand ohms and 10W can be connected in parallel at both ends of each phase winding of the reactor.

(3) Reduce the resistance of the varistor to increase the excitation current of the diesel generator set.

4. Insulation breakdown and short circuit of stator winding

(1) The stator winding is damp. For diesel generator sets that have been out of service for a long time or have been overhauled for a long time, the insulation resistance should be measured before being put into operation, and those that fail to pass are not allowed to be put into operation. The damp generator should be dried.

(2) Defects of the winding itself or improper maintenance process, causing winding insulation breakdown or mechanical damage. The insulation material should be selected according to the specified insulation grade, and the embedded winding and dipping and drying should be carried out in strict accordance with the process requirements.

(3) The winding is overheated. After the insulation is overheated, the insulation performance will be reduced, and sometimes it will quickly cause insulation breakdown at high temperatures. Routine inspections should be strengthened to prevent overheating of various parts of the diesel generator set and damage to the winding insulation.

(4) Insulation is aging. Generally, diesel generator sets have been operating for more than 15 to 20 years, and their winding insulation is aging, electrical performance changes, and even insulation breakdown. It is necessary to do a good job in maintenance and preventive tests of diesel generator sets. If the insulation is found to be unqualified, the defective winding insulation or windings should be replaced in time to extend the service life of the diesel generator set.

(5) Metal foreign bodies have entered the diesel generator set. Do not leave metal objects, parts or tools in the bore of the stator after the diesel generator set is overhauled; tighten the lashing line of the rotor and fasten the end parts to prevent the occurrence of damage. The centrifugal force will loosen.

(6) Excessive voltage breakdown:

1) The line is struck by lightning, and the lightning protection is not perfect, so the lightning protection facilities should be improved.

2) Misoperation, such as raising the rhythm voltage generated by members too high when there is no load. The diesel generator set should be boosted in strict accordance with the operating regulations to prevent misoperation.

3) The internal overvoltage of diesel generator set, including operating overvoltage, arc grounding overvoltage and resonance overvoltage, etc., should strengthen the winding insulation preventive test to find and eliminate the defects in the stator winding insulation in time.

5. Stator core slack

Due to improper manufacturing and assembly, the iron core is not fastened properly. If the entire iron core is loose, for small diesel generator sets, two iron plates smaller than the inner diameter of the stator winding end can be used, and studs can be used to tighten the iron core. After the original shape is restored, tighten the original clamping bolts of the iron core. If the local iron core is loose, you can first apply silicon steel sheet paint between the loose sheets, and then drive hard insulating materials into the loose parts.

6. Short circuit between iron chips

(1) The iron core lamination is slack, and the iron core vibrates when the generator is running, and the insulation is damaged; the insulation of individual parts of the iron chip is damaged or the iron core is locally overheated, which makes the insulation aging, and it is dealt with according to the method in the original plan.

(2) There are burrs on the edge of the iron chip or mechanical damage during maintenance.

Starlight Power was founded in 1974 and is one of the earliest manufacturers of generators and diesel generator sets in China. If you want get more information, welcome send email to sales@dieselgeneratortech.com we will pay highly attention on your question.