load of dry transformers

Loading of dry-type transformersis a topic that often raises questions, especially for those who are just starting to work in the electric power industry. Many people think it comes down to simple design power, but the reality is much more complex. During my work with various models, from simple household ones to large industrial ones, I became convinced that the “dryness” of a transformer is only part of the picture that determines its real performance and service life. The question is not only permissibleload, but also in its nature, impact on components, and, of course, in the correct design of the system as a whole. Let's try to figure out what we are talking about and what pitfalls should be taken into account.

What is a dry distribution device and why is it important?load?

A dry switchgear (DSD) is an electrical installation designed for distributing electricity under voltage up to 10 kV. It differs from traditional control systems, which use oil transformers, in the absence of oil. This certainly simplifies maintenance and reduces the risk of fire. But, like any other equipment, dry SRU has its limitations, andloadis one of the key parameters. Incorrect calculation or exceeding the permissible load can lead to overheating, premature failure of insulation and even an emergency.

Importanceloadsdue to the fact that it directly affects the heat dissipation in the transformer. Heat generation is the main enemy of electrical equipment. Overheating leads to insulation degradation, reduction in voltage rating and ultimately failure. Therefore, when designing a dry control system, it is necessary to carefully evaluate all possible scenariosloads, including peak values and variable operating modesload. We often encounter situations where the customer underestimates the expectedload, counting on future production growth, and this leads to serious problems already at the operational stage.

Factors influencing permissibleloaddry transformer

Acceptableloaddry transformer is not just a number from a passport. It is influenced by a whole range of factors that must be taken into account during design and operation. Firstly, these are climatic conditions. The higher the ambient temperature, the lower the permissibleload. Secondly, this is the altitude above sea level. At high altitudes, the air is less dense, which reduces the cooling efficiency of the transformer and requires reductionloads. Third is the type of cooling used in the transformer. There are transformers with natural air circulation, as well as with forced cooling by fans.

I remember one case when we were working on a project for a ceramics factory in the Caucasus region. The customer insisted on using a transformer of a certain capacity, citing future plans to expand production. We carefully analyzed all factors, including climate and altitude, and concluded that the proposed transformer would be overloaded. Following our recommendation, the customer chose a higher power transformer, which avoided problems in the future. This is a good example of how important it is not to skimp on calculations and take into account all the factors influencingload.

Influence of operating mode on durabilityloads

It is important to consider the operating mode of the transformer. Constantload, operating mode with variableloador operating mode with cyclic overloads - all this has different effects on the durability of the transformer. Cyclic overloads, for example when turning on powerful equipment, can lead to increased thermal stress in the insulation, which will eventually lead to its destruction. Therefore, when designing a system, it is necessary to provide soft start circuits to reduce peakloads.

Our engineering calculations often involve simulating various transformer operating conditions to determine the optimalloadand avoid overloads. We use specialized software that takes into account the influence of various factors on heat generation and voltage distribution in the windings.

Recommendations for calculation and monitoringloads

When calculatingloadsIt is necessary to take into account not only the rated power of the connected equipment, but also the simultaneity factor. The simultaneity factor is the ratio of the total power of the connected equipment to the rated power of the transformer. If the simultaneity coefficient exceeds 1, then it is necessary to reduceloadto the transformer to avoid overload. We recommend using modern monitoring systemsloads, which allow you to monitor heat generation, voltage and current in the windings of the transformer. This allows you to promptly identify signs of overload and take measures to prevent accidents.

Wenzhou Qiaonasen Electrical Equipment Co.,Ltd. specializes in the supply and installation of dry-type control systems of various capacities. We always pay special attention to calculationloadsand advise our clients on the operation and maintenance of equipment. We have many years of experience working with various transformer manufacturers and can offer the optimal solution for any project.

Common mistakes and how to avoid them

The most common mistake when designing a dry switchgear is underestimating the peakloads. Often, customers rely on average equipment power values, without taking into account possible short-term overloads. Another common mistake is choosing the wrong transformer. The transformer must be designed not only for the ratedload, but also for possible overloads and voltage fluctuations. You should not skimp on the quality of the equipment and the qualifications of the specialists who design and install the system.

We regularly encounter situations where customers try to use transformers rated for lessloadthan required. This leads to premature equipment failure and costly repairs. Therefore, when choosing a transformer, it is necessary to carefully study the technical documentation and consult with specialists.

The influence of insulation quality on the permissibleload

The quality of the insulation of the windings of a dry-type transformer is one of the key factors determining its permissibleload. The insulation is exposed to thermal and electrical stress, and its degradation leads to reduced strength and an increased risk of breakdown. Regular monitoring of the quality of insulation allows you to promptly identify signs of its degradation and prevent emergency situations. We offer services for diagnostics of transformer insulation using modern equipment.

When choosing a transformer, you need to pay attention to the insulation material and its characteristics. It is best to choose transformers with insulation made of polymer materials that have high heat resistance and resistance to chemical influences. Particular attention should be paid to the quality of insulation installation, since improper installation can lead to damage.