Transformer structure principle

General structure of the current transformer principle: simple structure of the current transformer, a primary winding insulated from each other, the secondary winding, core and frame, the housing, terminals and other components. Its working principle is basically the same transformer, circuit breakers the primary winding turns (N1) representing

Less directly connected in series in the power circuit, a load current () through a winding, the generated alternating magnetic flux induces a secondary current reduced proportionally (); number of turns of the secondary winding (N2) higher, and meters, relays, transmitters and other negative secondary current coil

Dutch (Z) in series to form a closed loop, because the primary winding and the secondary winding have equal ampere turns, I1N1 = I2N2, current electric transformer rated current ratio current transformer load impedance actual operation is very small, close to the secondary winding shorted state equivalent to a short-circuit

Operation of the transformer.
Feedthrough current transformer does not have its own structure of the primary winding, the carrier (load current) wires from the L1 to L2 through the rolling silicon steel coil made of round (or other shapes) from the core role of the primary winding. Secondary winding wound directly evenly on round cores, and instrumentation

, Relays, transmitters and other secondary load current coil in series to form a closed loop, since no feedthrough current transformer primary winding, the primary winding turns ratio based on the number of turns through the transformer iron hearts determined mandrel turns The more change than the smaller; contrary, wear

Heart turns less variable ratio greater than the rated current: where I1 - Peg one turn at a time rated current; n - mandrel turns.
Multi-tap current transformers. This type of current transformer primary winding unchanged during wound secondary windings, increasing the number of taps in order to obtain a plurality of different ratios. It has a fixed core and a number of turns of the primary winding, the secondary winding is insulated copper wire

Around the suit on the insulating core barrel, the different ratio of the secondary winding tap leads, then the wiring terminal block, each tap set their own terminals, thus forming a plurality of variable ratio, such current The advantage of transformer load current is changed according to

Ratio, secondary electrical wires swapped to change the ratio, without the need to replace the current transformer, to use more convenient.
Different current transformer turns ratio. This model has the same current transformer core and primary winding, and the number of turns of the secondary winding is divided into two different, separate windings, in order to satisfy the same load current ratio different circumstances, different levels of accuracy required

, For example, under the same load conditions, in order to ensure accurate measurement of energy required becomes relatively small number (to meet the load current in a rating of 2/3), the accuracy level higher (eg 1K1.1K2 of 200/5.0. 2); and protection of electrical equipment, test

Into account the large fault current protection factor, requires relatively large number of variables, the level of accuracy can be slightly lower (eg 2K1.2K2 as 300/5.1 level).
Adjustable primary winding, the secondary winding of the current transformer and more. This current transformer turns ratio range is characterized by numerous and can be changed, more common in high-voltage current transformer. Its primary winding is divided into two sections, respectively, through the transformer core, the secondary winding is divided into two with

Taps, the different level of accuracy independent windings. Transformer with a primary winding means connected to the outer connection piece, by changing the position of connection piece, that the primary windings connected in series or parallel connection is formed, thereby changing the number of turns of the primary winding in order to obtain a different ratio

. Tapped secondary winding is divided into two different ratios, their different level of accuracy winding, with a change in position of the winding connection piece, a corresponding change in number of turns, the ratio is changed, so that the formation a multi-span ratio. Tapped

Independent secondary windings with different ratios, and different level of accuracy, can be applied separately to energy measurement, indicating instruments, transmitters, relay, etc., in order to meet their different requirements.
Combined current and voltage transformers. Combined transformer by the current transformer and voltage transformer combination, multi installed in high-pressure metering boxes, cabinets, or used as a measurement of electrical equipment, power protection devices. Combined current and voltage transformers are the two

Or three current transformer primary and secondary windings and core and voltage transformer primary and secondary windings and iron core, steel body frame fixed on the transformer oil immersed fitted cabinets, first, the secondary winding outlet all leads, then in the box outside the high and low voltage porcelain

, The formation of an insulating, closed whole. Power line connecting the primary and secondary side protection devices and metering device or connection. Depending on the needs of current and voltage transformers combined into V / V wiring and Y / Y connection both, for the measurement of three-phase load balancing or

Imbalance of power.