BaktapurScb13 
MahendranagaHo
PatanOld box t& ldquo; YN, D11 & rdquo;, in which 11 indicates that when the working voltage phasor of the primary side line, refers to the position at 12 o'clock, the phase voltage phasor of the secondary side is at 11 o'clock. That is, the phase voltage UAB of the secondary side lags 30 degrees behind the working voltage uab330 of the primary side line (or 30 degrees ahead).
In order to better carry out the experiment of power transformer oil, it is necessary to sample the power transformer oil. The sampling work should be carried out on a dry sunny day. The commonly used containers and sampling methods during sampling do immediate harm to whether the specific quality of the oil can be truly reflected. The oil sample for AC voltage withstand test shall not be less than 0.5kg, and the oil sample for simplified experiment shall not be less than 1kg.
Grenoble.The rate of transformer is: n = P2 / p1x1o%, that is,GrenobleProduction process of oil immersed transformer, when the copper loss of transformer is equivalent to iron loss, the rate is very large. Therefore, the load of transformer is: 0 = P / PK. Fully consider the active power loss caused by reactive power in the system software during transformer operation. The load adjustment is: it can be seen from the calculation of load formula that the large rate of transformer does not occur when the load is full, Generally, it is about 50%, but when selecting the transformer capacity, we should select effective transformers according to the load condition and load, so as to make the transformer in the situation of economic development and achieve the goal of power saving.
Sound insulation treatment of main engine room the key to sound insulation treatment of dry-type transformer room is to start from three levels: window, ventilation and air exchange port and road surface, and apply sound insulation window, silencing cylinder, floating concrete floor damping pad and other sound insulation and noise reduction commodities to achieve sound insulation effect.
.When the power transformer operates at full load, it needs a large reactive load. This reactive load shall be provided by the power supply and distribution system. If the transformer volume is too large, it will not only increase the initial project investment, but also make the transformer operate at full load or load for a long time, expand the proportion of full load loss, there are few manufacturers of dry-type transformer that can reasonably guarantee the instantaneous step-up in China. The step-up dry-type transformer has strong step-up capacity and good practical effect. The difference depends on that the transformer power switch without excitation regulator does not have the ability to change gear with load. Because this kind of tap power switch can cut off the whole process in a short time during the whole process of gear change, cutting off the load current will cause arc burning between circuit breakers, so the dry-type transformer shall be powered off during regulation. Therefore, it is generally used as a dry-type transformer that is not very strict in voltage regulation and does not need to be adjusted frequently.
When the transformer is out of phase,GrenobleHow much is a 250kVA box transformer, if the second phase is blocked, there is still no sound when the second phase is sent and there is sound when the third phase is sent; If the third phase is blocked, the sound will not change as in the case of the second phase. There are three reasons for phase deficiency:
Installation requirements.What is the important role of power transformer
The input and output three-phase power lines shall be connected to phase a, phase B and phase C respectively according to the color of yellow, green and red bus duct of transformer terminal board. The zero line shall be connected to the neutral zero line of transformer voltage, and the grounding wire transformer casing and its transformer point shall be connected to each other. At ordinary times, the ground wire and zero wire are led out by the neutral wire of the transformer. (for example, the transformer box shall be matched with the ground wire mark of the shell and connected with each other). Check the input and output lines to ensure they are appropriate and accurate.
Different diversion methods,GrenobleEuropean box type transformer, dry-type transformers mostly use silica gel waterproof casing, while oil transformers mostly use porcelain waterproof casing;
After no-load test run is normal for 24h, it can be transferred to on-load operation, and the load shall be gradually increased from 25%, 50% and 75% by grade.
The cost is reasonable.Generally speaking, the ignition emergency treatment method of oil immersed transformer is mainly to disconnect the oil immersed transformer, disconnect the switching power supply on each side, quickly invest the reserved oil immersed transformer and start the power supply system from scratch. Stop the operation of refrigeration equipment. Key oil immersed transformer ignition. When L-type oil immersed transformer and high voltage station oil immersed transformer are ignited, the generator set must be disassembled first.
The rate of transformer is: n = P2 / p1x1o%, that is, the load of transformer is: 0 = P / PK. Fully consider the active power loss caused by reactive power in the system software during transformer operation. The load adjustment is: it can be seen from the calculation of load formula that the large rate of transformer does not occur when the load is full, Generally, it is about 50%, but when selecting the transformer capacity, we should select effective transformers according to the load condition and load, so as to make the transformer in the situation of economic development and achieve the goal of power saving.
The switching power supply lacks one phase of power;
Grenoble.When the power transformer operates at full load, it needs a large reactive load. This reactive load shall be provided by the power supply and distribution system. If the transformer volume is too large, it will not only increase the initial project investment, but also make the transformer operate at full load or load for a long time, expand the proportion of full load loss, reduce power factor and increase Internet loss. Such operation is neither economic development nor scientific.
The sampling container is a colorless glass bottle with a wide mouth ground glass plug with a volume of 0.5kg or 1kg. 2-3 bottles shall be collected at a time for analysis and experiment. Labels shall be attached during sampling. Pay attention to the name, source, sampling date, sampling person, weather conditions and other materials of the oil sample.
If you want to check the activated carbon fiber for the hanging cover, first take out the low-voltage waterproof sleeve and the on load transformer power switch, then lower the bell cover anchor bolt of the large cover slowly hang the galvanized steel wire rope with sufficient lifting net weight on the commonly used earrings, wear 4 round steel from top to bottom in the surrounding screw holes, and count the spacing and specifications for easy reinstallation. At the same time, the cable wind shall be added on all sides to ensure that the core international body will not be damaged during the whole lifting process. After lifting for 100mm, stop the lifting, stabilize the bell cover, and check the bearing capacity of the lifting core, center of gravity and Jack. After everything is normal, lift it again until the bell cover exceeds the relative height of the body, and rotate the crane to place the bell cover on the clean skid.