DE102004029434A1 - Transformer for wattless operation, employs five-limb core with secondary in center and balanced primaries closely adjacent on each side, fed in parallel - Google Patents

Abstract

Wattless operation of the transformer with loaded secondary, is achieved by inductive compensation of the primary working current, whilst fulfilling the following conditions. The transformer comprises two primary windings and one secondary, three windings in all. A five-limb core is used, the yokes (J1, J2) being connected to each other. All limbs are of the same thickness, and they are brought as closely together as possible. The secondary is located on the central limb. The primaries are on adjacent limbs, leaving the outer limbs coil-free. Primaries have the same number of turns and are connected to the power source in parallel. An independent claim is included for the corresponding method of operation.

Description

at known transformers, the wattless operation is only in the unloaded Condition possible, at the secondary side remains open.

Becomes a transformer on the other hand with Loads consumers of any kind, then arises in the secondary coil Secondary current of magnetic flux retroactively in the primary coil induces an active current, which causes the energy consumption becomes.

The However, experiment clearly shows that the inductive compensation the above-mentioned active current is basically possible without negative impact on the secondary performance to have.

at maximum load on the secondary side becomes no appreciable warming the transformer core observed.

In summary to lead these features to the invention specified in claim 1, the the problem of inductive compensation of the primary active current is based.

This Problem is solved by the features listed in claim 1 solved.

The iron core K of the in 1 illustrated transformer existing magnetic fluxes.

1. unloaded Status

In the transformer core K are only represented by Φ Φ _P1 and _P2 indicated Primae magnetic fluxes present Φ _P1 / 2 and Φ _P2 / 2 induce in the secondary coil, the secondary voltage U S _{S S}

2. Weighted condition

In the transformer core K, the magnetic fluxes Φ _P1 and Φ _P2 from (1) and the secondary magnetic flux indicated by Φ _S are present in this case.

3. Inductive compensation of the primary Active current.

The secondary partial flux Φ _S / 2, which acts on the primary coils P _S1 and P _S2, induces an active current in each (J "/ P1, J" / P2) and is due to the attractive effect of Φ _P1 / 2 and Φ _P2 / 2 which is exerted on him to the coil-free thighs over as in 1 shown.

During the transition, the P _S1 and P _{S2 are} completely cut by the secondary partial flux Φ _S / 2, so that in each coil an equally strong and the (J '' / P1, J '' / P2) opposite active current ('' / P1J, '' / P2J) is compensated for (J '' / P1, J '' / P2).

On the five-leg transformer core K three windings are mounted. (please refer 2 )

The primary coils P _S1 and P _S2 with the same number of turns and wire thickness are on the legs (b) and (d) and are connected in parallel in the correct sense, as in ( 1 ) or ( 2 ).

On the leg (c) is the secondary winding S _S.

The outer legs (a) and (e) each act as a magnetic shunt to leg (c), so that only a part (half) of the magnetic flux of the primary coil P _S1 and P _S2 passes through the secondary coil S _S.

The other half spreads on the legs (a) and (e) and magnetizes them.

The retroactive magnetic flux generated by the secondary winding S spreads to the legs (b) and (d), so that only a part (half) of this magnetic field passes through the primary winding P _S1 and P _S2 .

His Direction in the legs (b) and (d) agrees with the, through the legs (a) and (e) continuous primary Magnetic field match.

This results in the effect described in (S.1) under (3).

For transformation of the three-phase current must three identical transformers, primary and secondary interconnected be.

P _S1

primarily coil 1

P _S2

primarily coil 2

S _S

secondary coil

Φ _P1

primary magnetic flux of the coil P _S1

Φ _P2

primary magnetic flux of the coil P _S2

Φ _S

secondary magnetic load flow of the coil S _S

R

resistance

 G

power generator

I '' / P1

Primary active current of the coil P _S1

 '' / P1I

primary opposing active current of the coil P _S1

I '' / P2

Primary active current of the coil P _S2

 '' / P2I

primary opposing active current of the coil P _S2

K

iron core of the transformer

Claims (3)

The wattless operation of the secondary-loaded transformer is achieved by inductive compensation of the primary active current under the following conditions: 1.1 The transformer must consist of two primary windings and a secondary winding, ie a total of three coils. 1.2 The iron core of the transformer must consist of five legs which are connected to the J ₁ and the yoke J ₂ . 1.3 All thighs must be equally strong and should be brought together as close as possible. 1.4 The secondary coil must be placed on the middle leg. 1.5 The primary coils must be placed on the adjacent leg. 1.6 The outer legs must remain coil-free. 1.7 The primary coils must have the same number of turns. 1.8 The primary coils must be connected in parallel at the voltage source. Transformer according to claim 1, wherein the iron core from three thighs and one primary and a secondary one Coil exists. 2.1 The secondary coil must be on an outer leg be placed 2.2 The primary Coil must be mounted on the adjacent middle leg. 2.3 The second outer thigh must remain coil-free. Inductive compensation of the primary active current according to claim 1. By magnetic reaction of the secondary circuit of a transformer on the primary circuit must equal two in the primary coil strong opposing currents are induced.