Why Low Frequency is Harmful to Weichai Generator？
What is the meaning of the frequency reduction of Weichai generator and the impact on the equipment? We know that the low frequency of Weichai generator on the electrical equipment is unfavourable. Therefore, in order to maintain the rated value of the generator frequency, we need to use reasonable generator set maintenance methods to make necessary frequency adjustment. So, what impact does low frequency bring to Weichai generator?
When Weichai generator runs at low frequency, the turbine will generate mechanical vibration, and the turbine blades will be seriously damaged, which is very harmful to the turbine. Therefore, low frequency protection should be installed on large steam turbines. Low-frequency protection consists of low-frequency measuring elements and a time accumulation calculator. Because the harm of low frequency operation to the turbine is cumulative, it is related to the frequency drop value and duration.
1. The speed of the generator used by the user is related to the frequency of the system, and changes in the frequency of the generator will cause changes in the speed of the generator, which will naturally affect the quality of the product.
2. The instability of the frequency of the generator system will affect the normal operation of the electronic equipment.
3. The main plant mechanical equipment of the power plant, such as fans, the amount of air and water that can be supplied will decrease rapidly when the frequency of the generator is reduced, affecting the normal operation of the boiler.
4. The decrease of the frequency causes the rotation speed of the rotor to decrease, which reduces the amount of air blown by the two fans.The consequence is that the cooling conditions of the generator become worse and the temperature of each part increases.
5. Since the potential of Weichai generator is proportional to the frequency magnetic flux, if the frequency decreases, the magnetic flux must be increased to keep the potential constant. This will increase the excitation current, causing the temperature of the generator rotor windings to increase.
6. When the frequency decreases, in order to keep the machine voltage constant, it is necessary to increase the magnetic flux. This will easily saturate the stator core, the magnetic flux will escape, and some structural parts of the machine base will generate local high temperature, and some parts even spark.
7. The low frequency operation of Weichai generator will increase the pressure on the turbine blade, cause resonance of the blade, shorten the blade life, and even cause the blade to break.
8. When the generator is running at low frequency, the ventilation of the generator will decrease. In order to maintain the normal voltage, it is required to increase the generator excitation current and increase the temperature of the generator stator and rotor. In order not to exceed the temperature rise limit, the generator has to reduce the amount of electricity generated.
9. When the generator operates at a low frequency, the core loss and excitation current of the transformer will increase due to the increase of the magnetic flux density of the generator. In order not to exceed the temperature rise limit, the transformer load has to be reduced.
The speed of Weichai generator motor is closely related to the system frequency. Too low Weichai generator frequency will affect the normal operation of the equipment, reduce product quality, and even cause the entire system to collapse. Therefore, in order to avoid the impact of the system frequency drop, we need to set it according to the rated frequency of the system and adjust it in time when there is a frequency change, which has an important impact on the stable operation of Weichai power generator.
Weichai Generator is a Chinese brand diesel generator. Weichai Power not only produces Weichai series power generation engines, but also produces Baudouin series generating engines. Jiangsu Starlight Electricity Equipment Co.,Ltd. is authorised as Weichai diesel generator OEM supporting manufacturer, can provide 20kw to 3000KW Weichai (Baudouin) generators, including 50Hz and 60Hz generators.
Weichai diesel generator operating conditions and purposes under different power demand.
Continuous power (COP):
No operating time limited;
Running in constant 100% load ;
It does not have the ability of overload.
Purpose: Running in high temperature and high altitude conditions.
Prime Rated Power (PRP):
No operating time limited;
The average load factor shall not exceed 70% of the prime power in 250 continuous hours;
The time of running at 100% Prime Power no more than 500h each year;
It allow overload 10% power of 1 hour every 12 hours ,and the operating condition can't be more than 25 hours.
Purpose: For the power output has been agreed conditions, such as reduced utility power. The generator set can network to the utility grid.
Emergency Standby Power (ESP):
The time of running at standby power no more than 200h each year, include the operating condition of running over 25 hours in 100% load;
The average load factor shall not exceed 80% of the standby power in per 24 hours;
It does not have the ability of overload;
Starting the diesel engine without thermal process and from start to accelerate to rated speed required to be completed within 10s. When below ambient temperature 5°C, naturally aspirated diesel engines need to increase diesel preheat facility to ensure the water temperature is above 30°C; And on the way round when ambient temperature above 5°C. When the ambient temperature below 10°C, the turbocharged diesel engine need to increase diesel preheat facility to ensure the water temperature is above 30°C; And on the way round when ambient temperature above 10°C.
Purpose: Emergency power supply during power outages.