Minimum allowable insulation distance in dry transformer
The price of insulation is a major part of transformer price. In high voltage transformers of 110 and 220 thousand volts, the price of insulation can reach 18-25% of the entire transformer price. When the insulation gap in the insulation, the improper selection of material and size, if these gaps are fixed, the transformer can be damaged. If it is fixed, the insulation and other materials are wasted greatly, and the price of the whole transformer is improved. In order to correctly select the insulation structure, material, size and manufacturing technology, and to determine the length of the effective insulating gap correctly, it is necessary to know the effects of the insulation of the transformer in operation.
The influence of electric power: the power transformer is usually in the case of connection when it is used, so its insulation is under the influence of the rated working voltage for a long time, and he should bear the voltage without any damage in time. In a power system operating in a transformer, the overvoltage is nearly four times the value of the phase voltage in a few cases, due to a normal switching operation or an accidental accident. These voltages are measured in one percent seconds, usually less than 0.1 seconds. The overvoltage rating of the operating voltage and the switching operation is mainly affected by the main insulation of the coil, that is, the part of the coils and the insulation between the other coils.
The main insulation of dry type transformers often uses the same insulating parts as oil immersed transformers, such as insulated paper cartons, angle rings, component partitions, etc. In the design of dry type transformer insulation, in addition to ensuring insulation strength, special attention should be paid to adequate air cooling between the coils. Also, attention should be paid to the placement of insulation parts to ensure that air is exposed to the coil most smoothly.
The influence of electric power: the power transformer is usually in the case of connection when it is used, so its insulation is under the influence of the rated working voltage for a long time, and he should bear the voltage without any damage in time. In a power system operating in a transformer, the overvoltage is nearly four times the value of the phase voltage in a few cases, due to a normal switching operation or an accidental accident. These voltages are measured in one percent seconds, usually less than 0.1 seconds. The overvoltage rating of the operating voltage and the switching operation is mainly affected by the main insulation of the coil, that is, the part of the coils and the insulation between the other coils.
The main insulation of dry type transformers often uses the same insulating parts as oil immersed transformers, such as insulated paper cartons, angle rings, component partitions, etc. In the design of dry type transformer insulation, in addition to ensuring insulation strength, special attention should be paid to adequate air cooling between the coils. Also, attention should be paid to the placement of insulation parts to ensure that air is exposed to the coil most smoothly.