Daily maintenance of transformer and improvement of utilization rate
Writer： Hengfeng you electric Time：2023-04-20 views：times
The transformer in operation shall be inspected according to the regulations, the operation shall be supervised, and the operation specifications shall be strictly mastered to ensure safe operation.
1. Operation specification
(1) The allowable temperature is based on the operation of a 1600KVA dry-type transformer currently put into operation in the new plant. In the past two years, the maximum load in summer: when the current is 2100 amps and the temperature is about 105 degrees, the transformer operates normally, while the allowable temperature of dry-type transformer generally should not exceed 110 degrees and the maximum temperature should not exceed 120 degrees.
(2) It is allowed that the load in the operation of the transformer should be at the additional capacity, that is, the apparent power of the transformer. Generally, the transformer shall not operate beyond the additional capacity, but normal overload operation is allowed. During overload operation, it shall not exceed 10% of the transformer capacity, and pay attention to the temperature rise.
(3) Transformer three-phase unbalanced load when the three-phase is unbalanced, the maximum current of one phase shall be supervised. When the three-phase current is found to be seriously unbalanced, the average distribution of single-phase electrical equipment load shall be adjusted in time
(4) Generally, the power supply voltage of the voltage transformer shall not exceed 5% of the rated value, that is, the voltage of 10kV line shall not exceed 10.5kv and shall not be lower than 9.5kv.
2. Transformer maintenance
(1) The personnel on duty shall supervise the working load of the transformer according to the instructions of voltmeter, ammeter and thermometer, and report any abnormal conditions in time.
(2) During the peak load period in summer, strengthen the patrol monitoring of transformer load current and temperature, often check the working condition of cooling fan, and deal with abnormalities in time.
(3) Monitor whether the sound in operation is normal.
(4) Regularly check whether there is overheating, oxidation and corrosion at transformer lead joints, cables, buses, etc.
(5) In case of power failure of external network every year, the circulating air outlet at the top and bottom of the transformer room shall be vacuumed to ensure the smoothness of the air outlet. Wipe the dust on the surface of the winding pouring body with a rag, and check whether the winding pouring body has cracks and surface overheating damage. Check whether the fixing screw at the bottom corner of the transformer winding is loose.
(6) During normal operation, try to prevent opening the front and rear doors of the transformer room to prevent small animals (such as birds, mice, etc.) from entering the transformer room and causing accidents.
(7) Clean the environment around the transformer room frequently, and do not place any objects around the transformer.
(8) Frequently check whether there is water in the cable trench under the transformer room, resulting in the wet operation environment of the transformer. If found, deal with it in time to prevent moisture absorption of the transformer winding.
In recent years, with the continuous progress of society, electric energy has gradually become an indispensable energy in people's day and work. Therefore, in order to ensure the normal operation of the power system, it is necessary for the power department to carry out daily protection of electrical equipment. The operation task carried by the power transformer is increasing, which plays a very important role in the power system. Once there are shortcomings, the result is unimaginable, which will affect the operation of the whole power system and social stability. Therefore, the use efficiency of power transformer is also particularly important.
1. Select the transformer capacity according to the economic load rate. In addition to active power loss, there is also certain reactive power loss during transformer operation. In order to generate and transport these reactive power, active power loss will occur on generators, lines, condenser, capacitors and other equipment. Therefore, when considering the economic operation of transformer and recognizing the economic load rate, we should also consider the additional active power loss caused by no-load reactive power loss of transformer. In addition, when recognizing the economic load rate, we should also consider the fact that the load of the transformer is often changed.
2. Set different standard loss values for transformers with different load rates. Under different load conditions, the power of the transformer is different. To achieve economic operation, in addition to reducing the product of no-load loss and load loss of the transformer as much as possible, the appropriate ratio of no-load loss and load loss should also be selected to meet the economic load rate with the maximum power of the transformer as much as possible. Generator transformer. As the load rate is relatively high, in order to achieve economic operation, the manufacturer is required to reduce the load loss rate as much as possible. For Substation Transformers and distribution transformers, the load does not need to be large, and some are even small. The no-load loss value should be properly reduced and the load rate should be increased.
Therefore, the user should actually select the transformer capacity of the equipment according to the load rate recognized by the economic analysis. Sometimes, even if the "big horse and trolley" (i.e. the capacity utilization rate is less than 50%) is economical. It is necessary to investigate and guess the load change condition, and avoid the overload operation of the transformer, which is easy to cause the aging and damage of the transformer during the load paying operation.
3. Change cold standby to hot standby. In order to avoid the disadvantages of the transformer and its impact on the power grid, many users are equipped with standby transformer, which is called cold standby. For traveling power, the cold standby shall be changed to hot standby, that is, the normal transformer is also put into operation, but the load rate is not high. When one transformer is out of operation due to defects, others can still operate normally without overload. After changing cold standby to hot standby, the normal transformer load rate is close to the economic load rate and the operation power is increased.
For others, two different transformers are selected to separate the industrial power supply from the lighting power supply, which is also a good way to save energy.
4. Select parallel operation method. According to the actual situation, there is a great difference in seasonal load for the addresses with great changes in annual load, such as transformers used in drainage and irrigation stations, salt farms and other areas. In order to reduce no-load loss, in addition to selecting capacity regulating transformers, multiple (groups) of small capacity transformers can also be selected for parallel operation. All transformers are put into operation at the peak and only one (Group) is put into operation at the trough. Perhaps the \ "parent-child \" transformer is selected. At the peak, a large transformer is used, while at the low peak, the large transformer is automatically cut off and a small transformer is put into operation.
