Measuring Method of Transformer DC Resistance Tester

Measuring DC resistance is an important item in the oil immersed distribution transformer test. Through the measurement, you can check out the conductive circuit of the device whether the bad contact, poor welding, coil fault and wiring errors and other defects. In the actual measurement of small and medium-sized three phase pad mounted transformer, most of the DC bridge method, when the resistance of the coil in the test more than 1 European commonly used single-arm bridge measurement, 1 euro below the double-arm bridge is measured. In the use of double-arm bridge wiring, the potential of the bridge pile head close to the measured resistance, the current pile head to be connected to the top of the potential pile head. Before measuring, should first estimate the resistance of the coil under test, the bridge override button placed in the appropriate position, the non-measured coil shorted and grounded, and then turn on the power switch charging, to be fully charged after pressing the galvanometer switch, Quickly adjust the measuring arm so that the galvanometer pointer to the middle of the galvanometer scale zero line direction, fine-tuning, to be stationary when the pointer stopped at zero when the resistance value is recorded, this time, the measured coil resistance ratio = × Measure arm resistance. Measurements are completed, the first open galvanometer button, then release the power switch

Analysis of Cooling Mode of Dry - Type Transformer

substations and transformers cooling method is divided into natural air cooling (AN) and forced air cooling (AF). Natural air cooling, the transformer can be rated capacity under long-term continuous operation. Forced air cooling, the transformer output capacity can be increased by 50%. It is suitable for intermittent overload operation or emergency overload operation. The load loss and impedance voltage increase greatly due to overload, and it is in non-economic running state. Therefore, it should not be put into continuous overload operation for a long time.

The exhaust of the transformer

Inside the single phase step down transformer, there are two main parts: one is the insulation inside the transformer body and the gas inside the coil, and the other is the gas inside the transformer accessories, including the radiator, oil purifier, pressure relief valve, oil storage Cabinet, etc .; transformer body vacuum, their space and isolation of the oil immersed distribution transformer body internal space to be exhausted. Therefore, the implementation of the vacuum oil filling transformer and replenishment must be exhaust, exhaust is a very important step of the work, the specific approach is: "first on the next, the isolation tank, respectively, net."

Dry - type transformers to reduce the loss of the method

Dry-type transformers, we know that is a very wide range of current applications of a pole transformers, in many occasions has its wide range of applications, it is a very important power system transformers, but can not be ignored is that it is also a large energy consumption , Its loss accounts for half of the entire network loss, so that reduce the loss of the transformer is imminent. So, how do we reduce the energy consumption of dry-type transformers it? Here we analyze together.
On the one hand is to reduce the transformer material loss. Silicon steel sheet, steel, insulating material, magnet wire, transformer oil and so on are the necessary materials for transformers, these materials must consume a lot of energy, these materials save, indirect also save energy.
On the other hand is to reduce the loss of the transformer. Transformer losses include no-load losses and load losses. To reduce the load loss, need to use more copper or transposition wire and other measures; to reduce the no-load loss, the use of reduced flux density, the use of silicon steel or silicon steel, etc., thus increasing the three winding transformer manufacturing costs, the corresponding Sales prices also increased, it is necessary to consider the need to spend more money to run back to how long (that is, recovery period).
Can be said that you want to reduce the energy consumption of dry-type transformers is not an easy thing, the specific implementation of the relevant parties also need to carry out professional analysis to develop better energy-saving methods to achieve more energy efficient use of dry-type transformers.