Diesel generator sets are mechanical equipment that converts other forms of energy into electrical energy. It is driven by water turbines, steam turbines, diesel engines or other power machinery, and converts the energy generated by water flow, airflow, fuel combustion or nuclear fission into mechanical energy and transmits it to the diesel generator set. And then converted into electrical energy by a diesel generator set. Diesel generator sets are widely used in industrial and agricultural production, national defense, science and technology and daily life.
1. The diesel generator set is overheated
(1) Diesel generator sets do not operate in accordance with the specified technical conditions. If the stator voltage is too high, the iron loss will increase; the load current is too large, and the stator winding copper loss will increase; if the frequency is too low, the cooling fan speed will slow down and affect the diesel. The generator set dissipates heat; the power factor is too low to increase the rotor excitation current and cause the rotor to heat up. Check whether the indication of the monitoring instrument is normal. If it is abnormal, necessary adjustments and treatments shall be carried out to make the diesel generator set operate in accordance with the specified technical conditions.
(2) The three-phase load current of the diesel generator set is unbalanced, and the overloaded one-phase winding will overheat; if the difference between the three-phase current exceeds 10% of the rated current, it is a serious unbalanced phase current, and the three-phase current unbalance will cause Generate a negative sequence magnetic field, thereby increasing loss, causing heating of components such as the pole winding and ferrule. The three-phase load should be adjusted so that the current of each phase is as balanced as possible.
(3) The air duct is blocked by dust and poor ventilation, which makes it difficult for the diesel generator set to dissipate heat. The dust and grease in the air duct should be removed to make the air duct unobstructed.
(4) The inlet air temperature is too high or the inlet water temperature is too high, and the cooler is blocked. The temperature of the inlet air or inlet water should be lowered to clear the blockage in the cooler. Before the fault is eliminated, the load of the diesel generator set should be limited to reduce the temperature of the diesel generator set.
(5) Bearing too much or too little grease should be added according to the regulations, usually 1/2~1/3 of the bearing chamber (the upper limit is taken for the low speed, and the lower limit is taken for the high speed), and should not exceed 70% of the bearing chamber is appropriate.
(6) Bearing wear. If the wear is not serious, the bearing will locally overheat; if the wear is serious, it may cause friction between the stator and the rotor, causing the stator and rotor avoidance to overheat. The bearings should be checked for noise. If friction between the stator and the rotor is found, the machine should be shut down immediately for maintenance or bearing replacement.
(7) The stator core insulation is damaged, causing a short circuit between the sheets, causing the local eddy current loss of the core to increase and heating. In severe cases, the stator windings will be damaged. It should be shut down immediately for maintenance.
(8) The parallel wires of the stator winding are broken, causing the current of other wires to increase and heat. It should be shut down immediately for maintenance.
2. There is an abnormal voltage between the neutral line of the diesel generator set and the ground
(1) Under normal circumstances, there is a very low voltage due to uneven air gaps and unequal magnetic potentials under each magnetic pole due to the influence of high-order harmonics or manufacturing processes. If the voltage is one to several volts, it will not be dangerous , Do not have to deal with.
(2) The windings of the diesel generator set are short-circuited or the insulation is poor to the ground, which causes the performance of the electrical equipment and the diesel generator set to deteriorate, and it is easy to generate heat. It should be repaired in time to avoid the expansion of the accident.
(3) When there is no load, the neutral line has no voltage to the ground, and when there is a load, the voltage appears due to the three-phase imbalance. The three-phase load should be adjusted to make it basically balanced.
The above are the part reasons for why the diesel generator no generation, we will continue introduced it in the next article.
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 firstname.lastname@example.org we will pay highly attention on your question.