How to increase 5 mva power transformer specifications overload capacity?
1.What is 5 mva power transformer specifications overload capacity?
For the overload capacity of the transformer, it is actually related to a variety of reasons, such as the ambient temperature of the transformer, the load value performance before overload (initial load), the insulation level and heat dissipation of the transformer, and the length of the heating time. .
The overload performance of the transformer can exceed 25%-30% in a short period of time. The other long time does not exceed 10%.
This includes the calculation conditions formed by parameters such as ambient temperature, initial load, geometric multiple of overload, transformer oil temperature and winding temperature rise and hot spot temperature.
In this way, the overload capacity of the transformer can be released as much as possible.
In addition, the relevant research data shows that the 500 kV large-capacity substation transformer can control the transformer oil temperature 100 ℃ and the winding hot spot temperature according to the ambient temperature of 35 ℃, the initial load ratio of 100%, and the overload formation multiple of 1.8 times. 150 ℃, the principle of overload for 20 min for production and operation.
Next, we are more willing to discuss with you the progress of the times with the improvement of living conditions and the improvement of living conditions under the current conditions. The industrial production and domestic electricity demand of residents in various countries in the world are growing very fast, so higher and stricter requirements are put forward for the power supply capacity of the power distribution system of the country or individual.
Transformers play a major and important role in power distribution systems.
However, at the same time, the problem of overweight and overload of distribution transformers often occurs. If we explore the reasons behind it, in addition to the main reason of the increasing electricity load, the number of three-phase phases is unbalanced, and the data of the equipment collection system is inconsistent. Other reasons such as normal can not be ignored.
Therefore, according to different situations, we should first analyze the main causes of the transformer overload and overload problems, and then propose targeted solutions according to the reasons, so as to achieve the goal of controlling this phenomenon at the same time, and at the same time reduce the cost in the entire governance process.
2.So what are the influencing factors of 5 mva power transformer specifications overload?
The distribution transformer load rate can be understood as the ratio of the maximum load carried by the transformer to the rated capacity of the equipment.
The normal annual maximum load rate of distribution transformers is between 20% and 80%.
Generally speaking, a light overload distribution transformer refers to a transformer whose annual maximum load ratio is less than 20%.
Severely overloaded distribution transformers refer to transformers whose annual maximum load ratio is between 80% and 100%.
The overload distribution transformer refers to the transformer whose annual maximum load rate is greater than 100%.
From the definition and introduction formula described above, it can be known that the load and capacity of the transformer directly affect the load rate of the transformer.
Then we will further analyze and summarize these two factors, and we can conclude that the influence factors of the light and heavy overload of the distribution transformer include two aspects: the capacity planning value of the transformer and the operation performance of the transformer. In terms of distribution and transformation capacity planning, a reasonable ratio of transformer capacity to the expected transformer load in the area of use can increase the proportion of normal load distribution and transformation. On the contrary, a relatively low ratio of distribution transformer capacity to regional load will cause the general distribution transformer overload phenomenon. The higher ratio of distribution transformer capacity to regional load will cause the general distribution transformer light load phenomenon.
In the aspect of distribution transformer operation, the sudden change of load, the difference between the predicted value and the actual growth value, and the three-phase imbalance can all cause the problem of distribution transformer load rate.
Among them, the sudden change of the distribution transformer load and the difference between the load forecast and the actual growth can lead to the problem of light and heavy overload of the distribution transformer. The problem of heavy overload, etc., and the three-phase unbalanced factors are more to cause the problem of heavy overload of the distribution transformer.
3.So what solutions of 5 mva power transformer specifications can we consider?
3.1 Transform the existing distribution transformer and replace the large-capacity transformer.
For the existing power distribution equipment with long operating years and poor state evaluation results, or small-capacity distribution transformers that are high energy-consuming equipment (such as S7 distribution transformers) and have low safety and reliability, capacity-enhancing transformation should be considered to solve the problem. Considering the transformation according to the specific situation, the power supply area is re-divided by adding new distribution transformers and changing the location of existing distribution transformers, and scientifically and rationally arranging the power supply mode. According to the evaluation results of distribution transformer status, choose to scrap or rotate the returned distribution transformer.
3.2 Data Accuracy Verification, Analysis and Overload Governance Process
(1) The transportation inspection department sends the load data to the equipment operation management unit. The equipment operation management unit verifies on site whether the capacity of the distribution transformer with a load rate exceeding 80% is consistent with the monitoring system. If not, the equipment operation management unit shall modify the equipment in the PMS. At the same time, measure the power distribution operation data (current) on site to check whether the equipment failure in the low-voltage station area has caused heavy overload. If the equipment is operating normally and the actual data is quite different from the monitoring platform data, the electricity consumption information collection system collection terminal shall be detected. Whether it is abnormal, if abnormal, replace the acquisition terminal, if there is no difference, calculate the actual load rate according to the actual capacity. At the same time, the equipment operation management unit regularly measures the equipment under its jurisdiction to prevent the abnormal data collection and monitoring platform, and timely feedback the information of the unmonitored equipment to the transportation inspection department.
(2) The equipment operation management unit cooperates with the transportation inspection department to analyze the three-phase current imbalance of the distribution transformer with a load rate of more than 80%, and the equipment operation management unit determines whether the corresponding station area of the severe three-phase unbalanced distribution transformer has phase adjustment, The cutting load addresses the possibility of heavy overloading.
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At the same time year-on-year and month-on-month data analysis of whether the station area is heavy overload for a long time or a short-term abnormal surge in load. If there is an actual (long-term) heavy overload, the transformer rotation process shall be activated, and the connection of low-voltage electricity loads in the station area shall be stopped.
（3）The equipment operation management unit cooperates with the transportation inspection department to analyze whether the distribution transformers with a load rate of 60%-80% have heavy overloads according to the previous heavy overload records, and analyze the recent load growth trend to demonstrate whether there will be actual heavy overloads. , and control the load access. The equipment operation management unit shall report to the Marketing Department that the expansion and installation of the low-voltage industry in the Taiwan area is restricted, and the emergency infrastructure project package for industry expansion shall be used for emergency treatment. If there is heavy overload in the same period, notify the equipment operation management unit to verify the data on site, and prepare for transformer rotation in advance if it is true.
(4) The equipment operation management unit cooperates with the transportation inspection department to analyze the load growth of distribution transformers with heavy overload and distribution transformers with a load rate of 60%-80% in the past year, and check the surge in load and serious three-phase imbalance. Whether the Taiwan District has been included in the next year's overhaul and technical transformation project reserve, if not included in the reserve, the Transportation Inspection Department will propose an implementation plan and organize the design unit to compile the project reserve data, and report it to the Development and Construction Department and Transportation Inspection Department of the listed company for review. The municipal company shall report it to the provincial company for review and be included in the project reserve for the next year. At the same time, it is checked whether the Taiwan districts that have started the emergency process for business expansion due to emergencies have been included in the reserve for the next year. If they have been included in the emergency projects, they shall be reported to the relevant departments of the listed company to adjust the reserve project database at the end of the quarter to prevent duplication of projects. After the project is issued, the old equipment can be returned to the warehouse for storage and regular electrical tests are carried out, and the equipment can be used for later use.
3.3 Add distribution and transformation points to reasonably divide the power supply area
For the power supply area where the existing distribution transformer capacity is small, the average household capacity is low, and the existing distribution transformer operating conditions are good, priority should be given to the new distribution transformer distribution points, and the purpose of reducing the distribution transformer load rate is achieved by rationally distributing the load. New distribution transformers should be as close as possible to the load center in accordance with the principle of "small capacity, densely distributed points, and short radius". According to the load density, reasonably reduce the large-capacity distribution transformers above 400kVA and avoid long-distance power supply. 100kVA and 200kVA distribution transformers should be used first, scientifically divide the power supply area, shorten the power supply radius, and try to make the distribution transformers as close to the load center as possible, and scientifically determine the distribution transformers Place the address.
3.4 The light and heavy overload control method of distribution transformer based on resource optimization
In view of the coexistence of light and heavy overload problems of distribution transformers and the large base of distribution transformers, this paper proposes a management method for light and heavy overload of distribution transformers based on resource optimization. The main purpose of the resource-optimized distribution transformer management method is to comprehensively optimize the distribution transformer resource allocation in the region, and reduce the problem of light and heavy overload caused by the mismatch between the distribution transformer capacity and the load in the region. It takes the heavy overload transformer as the starting point, carries out the operation and maintenance of the distribution transformer, reduces the operation risk of the heavy overload transformer, and takes into account the transformer under light load, so that the distribution transformer load rate complements the advantages and disadvantages, and improves the utilization of the overall distribution transformer resources. Rate. The following factors should be considered in the light and heavy overload control method of resource-optimized distribution transformers.
The matching factor of the distribution transformer capacity, the heavy overload distribution transformer capacity should be smaller than the light load distribution transformer capacity, and after the operation and maintenance exchange, the load rate is in the normal load rate range.
The basic matching factors of distribution transformers, and the types of distribution transformers are the same, that is, the distribution transformer types (distribution room, column, box type), and distribution transformer insulation cooling methods (dry type, oil immersion) are the same to ensure that the basic structure is consistent. applicability.Load growth factor, the load growth of the two distribution transformers to be optimally allocated should be considered, and the distribution transformers with stable or small increase in load should be selected for replacement, so as to avoid re-distribution due to short-term load growth after replacement. Overload problem. The resource optimization management method is based on the optimization of distribution transformer resources, matching and exchanging large-capacity and light-load distribution transformers with small-capacity, heavy-load and overload distribution transformers, reducing the operation risk of heavy-load distribution transformers and improving the load rate of light-load distribution transformers. , to achieve the optimal allocation of distribution transformer resources, and the overall distribution transformer runs at a good load rate level.
