河北铁芯厂

一、 允许温度

1. Permissible temperature

变压器运行时，它的线圈和铁芯产生铜损和铁损，这些损耗变为热能，使 变压器的铁芯和线圈温度上升。若温度长时间超过允许值会使绝缘渐渐失去机 械弹性而使绝缘老化。

When the transformer is running, its coils and core produce copper and iron losses, which turn into heat to increase the temperature of the core and coil of the transformer. If the temperature exceeds the allowable value for a long time, the insulation will gradually lose the mechanical elasticity and make the insulation aging.

变压器运行时各部分的温度是不相同的，线圈的温度最高，其次是铁芯的 温度，绝缘油温度低于线圈和铁芯的温度。变压器的上部油温高于下部油温。 变压器运行中的允许温度按上层油温来检查。对于 A 级绝缘的变压器在正常运 行中，当周围空气温度最高为 400C 时，变压器绕组的极限工作温度是 1050C。 由于绕组的温度比油温度高 100C，为防止油质劣化，规定变压器上层油温最高 不超过 950C，而在正常情况下，为防止绝缘油过速氧化，上层油温不应超过 850C。对于采用强迫油循环水冷却和风冷的变压器，上层油温不宜经常超过 750C。 (这种变压器上层油温最大允许值为 800C)

When the transformer is running, the temperature of each part is different. The temperature of the coil is the highest, followed by the temperature of the core, and the temperature of the insulating oil is lower than the temperature of the coil and the core. The upper oil temperature of the transformer is higher than the lower oil temperature. The permissible temperature in the operation of the transformer is checked according to the temperature of the upper oil. For a class a transformer in normal operation, when the ambient air temperature is up to 400C, the ultimate working temperature of the transformer winding is 1050C. Because the temperature of the winding is 100C higher than that of the oil, the upper layer oil temperature of the transformer shall not exceed 950C, in order to prevent the deterioration of the oil quality. Under normal circumstances, to prevent the oxidation of the insulating oil from overheating, the upper layer oil temperature should not exceed 850C. For the transformer using forced oil circulating water cooling and air cooling, the upper oil temperature should not be more than 750C. (the maximum permissible value of the upper oil temperature of this transformer is 800C)

二、 允许温升

Two. Allow temperature rise

只监视变压器运行中的上层油温，还不能保证变压器的安全运行，还必须 监视上层油温与冷却空气的温差—即温升。 变压器温度与周围空气温度的差值， 称为变压器的温升。对 A 级绝缘的变压器，当周围最高温度为 400C 时，国家 标准规定绕组的温升 650C， 上层油温的允许温升为 550C。 只要变压器温升不超 过规定值， 就能保证变压器在额定负荷下规定的运行年限内安全运行。 (变压器 在正常运行时带额定负荷可连续运行 20 年)

Only monitoring the upper oil temperature in transformer operation can not guarantee the safe operation of transformer. We must also monitor the temperature difference between the upper oil temperature and the cooling air, that is, the temperature rise. The difference between the temperature of the transformer and the ambient air temperature is called the temperature rise of the transformer. For a class a transformer, when the maximum temperature around is 400C, the national standard stipulates the temperature rise of 650C, and the permissible temperature rise of the upper oil temperature to 550C. As long as the temperature of the transformer does not exceed the specified value, it can ensure the safe operation of the transformer within the specified operating period under the rated load. (the transformer can run continuously for 20 years with the rated load in normal operation)

三、 合理容量

Three. Reasonable capacity

在正常运行时，应使变压器承受的用电负荷在变压器额定容量的 75—90% 左右。

In normal operation, the power load of the transformer shall be about 75 - 90% of the rated capacity of the transformer.