There is a magnetic induction line crossing in the transformer core， which will cause induced electromotive force on the plan perpendicular to the magnetic induction line. Because this electric flow creates a closed loop to generate an electric field and forms a vortex， it is called vortex. The existence of vortex makes the transformer core hot and consumes kinetic energy. This kind of loss is called vortex loss.
1The efficiency of transformer is closely related to the output power level of transformer. Generally， the greater the output power， the smaller the loss to output power ratio and the higher the efficiency. On the contrary， the smaller the output power，Products Show the lower the efficiency.
yZhangui NoraCommon problems of tap changer of power transformer
It is understood that in China，Ka-thia-war Characteristics of oil immersed transformerHow to buy cost-effective transformers have experienced the whole process of replacing many series products such as S. As early as the middle and late s， S Series lossless distribution transformers were selected in China to replace the high energy consumption transformers of jb- and jb - Specifications operating in the power network at that time. Since the th century， urban power grids have been transformed all over the country， and S series distribution transformers have been used to replace S Series. In recent years， S and S commodities are gradually selected in large quantities in the transformation of urban and rural power networks in China， low noise， fire safety and explosion-proof and high reliability. There are two key development prospects: one is the development trend of high voltage and high voltage， especially kV and kV. The second is the development trend towards environmental protection， energy conservation and miniaturization. The former key is applied to the long-distance substation project route，Products Show and the latter key is applied to the substation project route in big cities.
UlThe appropriate power saving calculation formula should be derived from the following process: active power loss of large capacity transformer: load of large capacity transformer; PDK - short-circuit fault loss of large capacity transformer， kW. Active power loss of small capacity transformer: when a pump room is in normal operation， two pumps are started separately and each pump is driven by kW motor， so the usual load is KW， CST = . One kva transformer was originally configured
Overtemperature alarm and trip: collect winding or iron core temperature data signals according to the temperature measurement resistor of PTC discrete system thermistor embedded in the bottom voltage winding. When the transformer winding temperature rises again， if it reaches ℃， the overtemperature trip data signal must be transported to the secondary maintenance circuit， and the transformer shall be tripped quickly.
The grounding resistance of， high voltage and bottom voltage shall not be less than % (m & omega;) of the original value. The difference between the three-phase mean value of winding resistance measurement at the same temperature shall not exceed %， which shall not exceed % compared with the last accurate measurement result.
dThe time difference between different steps of three-phase power switch of switching power supply shall be less than ms，Products Show the closing shall be maintained by high-voltage arrester， and the neutral line of transformer shall be reliably grounded (it shall be grounded immediately).
AOvertemperature alarm and trip: collect winding or iron core temperature data signals according to the temperature measurement resistor of PTC discrete system thermistor embedded in the bottom voltage winding. When the transformer winding temperature rises again，Ka-thia-war Characteristics of oil immersed transformerHow to buy cost-effective if it reaches ℃， the system software outputs the overtemperature alarm system; If the temperature rises to ℃ again and the transformer can no longer operate， the overtemperature trip data signal must be transported to the secondary maintenance circuit， and the transformer shall be tripped quickly.
QWhere is goodDuring the operation of the transformer， the resistance value of the grounding wire shall be measured accurately every two years.
mPDry type transformer is a common electrical equipment which can be used to convert the alternating voltage of one standard value into another standard value of the same frequency. The step-up dry-type transformer is used to convert the low-grade alternating voltage into another high-grade alternating voltage of the same frequency. It is widely used in high-frequency industries， such as variable frequency power supply.
Dry type transformer， a static electrical equipment， is used to change the AC current (current) of a certain standard value into another or several types of working voltage (current) with the same frequency and different standard values. According to the supervision sampling inspection data released by AQSIQ in the third quarter of last year，Power transformer price: 1000KVA, 33kV, 25kV, power transformer, oil immersed transformer, dry-type transformer factory among the kinds of dry-type transformer commodities produced and manufactured by companies in provinces and municipal districts across the country， kinds of commodities were found to be inconsistent with the provisions of relevant specifications， with a compliance rate of %& ldquo; This result mostly shows the quality level of Chinas dry-type transformer industry at the present stage.
Transformer manufacturers generally adopt IP protective casing， which can avoid the entry of solid dirt with a diameter of more than mm， rats， cats， birds and other animals， resulting in vicious common faults such as short-circuit fault and power failure， and provide a safe natural barrier for the energized part. If the transformer equipment must be outdoors， IP protective casing can be adopted， which can avoid being equally divided with the above IP protective effects However， IP casing will reduce the refrigeration capacity of the transformer， so pay attention to the reduction of its operating volume.
Application processdThe transformer manufacturer said that the temperature display equipment: the temperature change value is measured according to the PT temperature sensor embedded in the bottom voltage winding to immediately indicate the winding temperature of each phase (three-phase safety inspection and Zui large value indication， and the historical time Zui high temperature can be recorded). The Zui high temperature can be input and output as mA analog quantity. If it is to be transmitted to a distance (the distance can reach m， the electronic computer can be equipped with an electronic computer socket， an intelligent transmitter and transformers can be detected. The over temperature alarm and trip of the system software can also be signaled by the resistor data of Pt thermistor sensor， so as to further improve the stability of the temperature maintenance system software.
PWhen we apply oil immersed transformer， we all know that it operates with the help of oil，
Hand touch method for transformer inspection
yZhangui NoraOil sample inspection & mdash; & mdash; the performance parameters such as compression resistance and residue shall be carried out every three years. The long-term overload or overload of the transformer can reduce the cycle time.
jSVisual inspection method for transformer inspection
The fundamental reason for this kind of inaccuracy is that when the transformer & ldquo; Dalar trolley & rdquo; is considered according to the size of capacity utilization rate， and then the iron loss is considered and the copper loss is ignored. In fact for a certain load， the active power loss of small capacity exceeds that of large capacity The active power loss of the transformer， so it consumes electromagnetic energy.