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36kv potential transformer 36kv voltage transformer magnetic voltage transformers, View 36kv potential transformer, SAGHU Product Details from Zhejiang Shanghu Electrical Co., Ltd. Electrical Engineering Stack Exchange is a question and answer site for electronics and electrical engineering professionals, students, and enthusiasts. If the two parallel straight wires are infinite in length and with zero thickness, the distance between the two doesn't matter at all, and therefore will not appear in any equation.
If you put two inductors close to each other, the changing (Credits to Curd) field generated by one will induce (sorry for the pun) a current in the other one, with the proportion given by the number of windings (because of Faraday's law of induction). This translates in a higher efficiency of the coupling, as almost all the magnetic field is induced in the secondary, as opposed to the previous case. Since this field is distributed through all the wire, it will be much weaker than using windings, because these have the effect to concentrate this field into the inner space (where is the core). As for inductors, distance reduces the portion of the magnetic field that the wires share, and with it the power transferred. With no core, distance decreases the coupling inductance and increases the leakage inductance. As coupling is decreased, such as by increasing distance, more of the primary's impedance comes from leakage inductance and the series component that is the resistor accross the secondary reflected to the primary gets less and less. Knowing you are an engineering student with a brilliant imagination, and you know how iron filings collect around a wire to show the magnetic flux, you need to use laminated iron steel to couple the high power low frequency power to the secondary wire, or a ceramic ferrite core for higher frequencies that have smaller size and less loss than iron. There are many shapes and sizes depending on whether you need a fire hose or a garden hose or a sewer hose.
But if you own a soldering gun, you have a transformer with many primary turns and only 1 secondary turn that will heat the heavy copper tip enough to melt solder in a second. In this expression the dimensions \\$l\\$ and \\$d\\$ are centimeters and the inductance is microhenrys. Not the answer you're looking for?Browse other questions tagged transformer theory or ask your own question. Primary re-connectable means that the primary circuit connection has to be changed to change the ratio. Secondary re-connectable means that the ratio can be changed by utilizing tappings in each of the secondary cores. With an ideal current transformer under short-circuited conditions, there is always a balance with the ampere turns, meaning that the product of primary current and primary winding turns equals the product of secondary current and secondary winding turns.
The behavior of current transformers and the conformities to basic electrical laws can be demonstrated by the use of equivalent circuit shown below. From the above equivalent circuit, it can be seen that with a non-ideal transformer there are always some errors included in the measurement. It can also be further observed that if the CT secondary side is left open-circuited (infinite burden connected), the whole primary current starts to excite the CT, resulting in overloading and induced dangerous voltage in the secondary terminals. The detailed core data describes the core performance with respect to the intended application. The transformer has dual-ratio re-connection (from secondary) possibilities and two second-ary cores. If not otherwise stated, the maximum continuous allowed primary current is the same as the rated primary current. The instrument security factor (Fs) describes the transformer’s saturation with rated primary current multiples.
Primary current of magnitude five times (Fs 5) the rated primary current causes a combined error of at least 10%. The secondary rated burden of the measurement core changes according to the used secondary re-connection (tapping).
The marking 5P10 is a combination of two things, namely the accuracy class of 5P and accuracy limit factor of 10. Electrical Corner StoreCheck out our new #Electrical Corner Store with selected Electrician's Books, Testing and Safety equipment and other electrician's stuff! Science at GlanceOur mission is to be the leading provider of scientific information in the field of power and engineering in general.

Unlike cooling-fan or pump noise, the sound radiated from a transformer is tonal in nature, consisting of even harmonics of the power frequency. The low frequency, tonal nature of this noise or buzzing makes it harder to mitigate than the broadband higher frequency noise that comes from the other sources. To address this problem, most noise ordinances impose penalties or stricter requirements for tonal noise. Even though the core is the principal noise source in transformers, the load noise, which is primarily caused by the electromagnetic forces in the windings, can also be a signi?cant in?uence in low-sound-level transformers. The cooling equipment (fans and pumps) noise typically dominates the very low-and very high-frequency ends of the sound spectrum, whereas the core noise dominates in the interme-diate range of frequencies between 100 and 600 Hz. ABB Distribution Transformers are manufactured in the range 50 – 30000 kVA, for operating voltages up to 72,5 kV. When a strip of iron is magnetized, it undergoes a very small change in its dimensions (usually only a few parts in a million). The change in dimension is independent of the direction of magnetic ?ux; therefore, it occurs at twice the line frequency. Flux density, core material, core geometry, and the wave form of the excitation voltage are the factors that in?uence the magnitude and frequency components of the transformer core sound levels. Load noise is caused by vibrations in tank walls, magnetic shields, and transformer windings due to the electromagnetic forces resulting from leakage ?elds produced by load currents.
The load noise is predominantly produced by axial and radial vibration of transformer windings.
However, marginally designed magnetic shielding can also be a signi?cant source of sound in transform-ers. Studies have shown that except in very large coils, radial vibrations do not make any signi?cant contribution to the winding noise.
The compressive electromagnetic forces produce axial vibrations and thus can be a major source of sound in poorly supported windings. Through several decades, the contribution of the load noise to the total transformer noise has remained moderate. However, in transformers designed with low induction levels and improved core designs for complying with low sound-level speci?cations, the load-dependent winding noise of electromagnetic origin can become a signi?cant contributor to the overall sound level of the transformer. In many such cases, the sound power of the winding noise is only a few dB below that of the core noise. Power transformers generate considerable heat because of the losses in the core, coils, and other metallic structural components of the transformer. Cooling fans usually contribute more to the total noise for transformers of smaller ratings and for transformers that are operated at lower levels of core induction. Factors that affect the total fan noise output include tip speed, blade design, number of fans, and the arrangement of the radiators. Hi Edward, How about determine transformer losses and efficiency using nameplate data or rule of thumb.
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DescriptionThe voltage transformer of the type JDJ(J)2-35 is single phase and oil-filled product. If you require further details regarding the transaction data, please contact the supplier directly.
But this coupling will be limited to the portion of the field which falls in the area of the second inductor, which can or cannot be a limited portion of the total.
Note that with the core, in the ideal case in which all the flux is convoyed the distance doesn't matter, as all the flux is into the core. The transformer’s secondary circuits usually consist of several units, each of them having its own magnetic core and winding. This can mean that all or some of the windings have more than one ratio from which to choose. These errors are mainly caused by the excitation current (Ie) and the load current (I2), which introduces both ratio errors and angle errors between the reduced primary current and the actual secondary current.

This data can be expressed according to guidelines of one of the several international standards, like IEC, British Standards or IEEE. It is assumed here that a three-phase current transformer set, having the below shown data labels, is used for energy measurement and overcurrent protection. In some cases, it is specially stated that the maximum allowed continuous current is for example 120% of the rated primary current.
To comply with this accuracy class, the transformer has to fulfill certain requirements regarding current error and phase displacement error as shown below.
This is an important factor for securing the capability of the connected measuring devices to withstand the injected currents during power system faults. The protective feature for measurement devices is the better the lower the overcurrent limit factor is.
The complete marking 5P10 indicates that the composite error will not exceed 5% with ten times the rated primary current when the rated secondary burden is connected.
Highly specialized for design of LV high power busbar trunking (<6300A) in power substations, buildings and industry fascilities.
Every day, the generation and usage of energy produces more pollution than any other single industry.
Also, tonal noise can be perceived more acutely than broadband levels, even with high background noise levels. Transformers are three phase, mineral oil filled, naturally cooled (ONAN) and can be used in indoor and outdoor operations. Because the magnetostriction curve is nonlinear, higher harmonics of even order also appear in the resulting core vibration at higher induction levels (above 1.4 T). The mechanical resonance in transformer mounting structure as well as in core and tank walls can also have a signi?cant in?uence on the magnitude of transformer vibrations and, consequently, on the acoustic noise generated. A rigid design for laminated magnetic shields with ?rm anchoring to the tank walls can greatly reduce their in?uence on the overall load sound levels. An appropriate mechanical design for laminated magnetic shields can be helpful in avoiding resonance in the tank walls. In some cases, the natural mechanical frequency of winding clamping systems may tend to resonate with electromagnetic forces, thereby severely intensifying the load noise.
Transformer noise is sometimes very hard to remove or mitigate without actually repairing it.
The secondary core data, except for the ratio, remains the same with either of the ratio selections.
The underlined value shows the presently utilized ratio, where the selection possibility exists. It should be further noticed that the given overcurrent limit factor value applies with the stated rated burden and is subject to change if the actual burden differs from the rated burden. This combination of low attenuation and high perception makes tonal noise the dominant problem in the neighboring communities around transformers.
The design of the magnetic shields should take into account the effects of overloads to avoid saturation, which would cause higher sound levels during such operating conditions. The difference between low voltage kwh meter and utility company kwh meter difference is up to 30%. I have been asked this Question in the Electric machines lab .Where our Lab engineer asked us to tell what is the source of sound in Transformers ! The presence of harmonics in load current and voltage, most especially in recti?er transformers, can produce vibrations at twice the harmonic frequencies and thus a sizeable increase in the overall sound level of a transformer. This product could supply standard volt to voltage meter’ power and wait -hour meter, besides, it also can supply volt to earthing relay and earthing leak hunting device, so as to realize earthing alarm and leak-hunting function, consequently, it will replace earthing voltage transformer composed of JSJW and JDZJ model product.