The Key Selection points of Oil-Immersed Distribution Transformer.
Load Properties of Distribution Transformer:
1) When there are a large number of primary or secondary loads, it is advisable to install two or more transformers. When one transformer is disconnected, the capacity of the remaining transformers can meet the demand of primary and secondary loads. First, the secondary loads should be concentrated as far as possible and should not be too dispersed.
2) When seasonal load capacity is large, special transformer should be installed. For example, in large civil buildings, the load of air conditioning refrigerators, heating electricity and heat, etc.
3) When the concentrated load is large, special transformer should be installed. Such as large heating equipment, large X-ray machine, electric arc furnace, etc.
4) When the lighting load is large or the power and lighting use common transformer seriously affects the lighting quality and lamp life, special lighting transformer can be set up. In general, power and lighting share transformers.
The Use Environment of Distribution Transformer:
Under normal medium conditions, oil-immersed transformer or dry-type transformer can be selected, such as industrial and mining enterprises, agricultural independent or attached substations, residential independent substations, etc. The transformers available are S8, S9, S10, SC (B) 9, SC (B) 10, etc.
(1) Maintaining long-term stability at 220℃
(2) It can withstand short-term operation at 350 ℃.
(3) Stable performance in a wide range of temperature and humidity.
(4) At 250 ℃, it will not melt, flow and combustion-supporting.
(5) No toxic or corrosive gases will be released at 750℃.
Electric Load of Distribution Transformer
1) The capacity of distribution transformer should be integrated with the facility capacity of various electrical equipment, and the calculated load (generally excluding fire load) should be calculated. The apparent capacity after compensation is the basis for selecting the capacity and number of transformers. The load rate of general transformer is about 85%. This method is simple and can be used to estimate capacity.
2) In GB/T17468-1998 “Guidelines for Selection of Power Transformers”, the recommended capacity selection of distribution transformers should be determined according to GB/T15164-94 “Guidelines for Load of Oil-immersed Power Transformers” or GB/T17211-1998 “Guidelines for Load of Dry Power Transformers” and calculation load. These two guidelines provide computer programs and normal periodic load diagrams to determine the capacity of distribution transformers.