SN EN 61378-1 : 1998

1 General
    1.1 Scope
    1.2 Classification
    1.3 Normal service conditions
2 Normative references
3 Definitions
4 Ratings
    4.1 Rated power at rated frequency and load capability
    4.2 Rated and service voltages
    4.3 Rated current
5 Load loss and voltage drop in transformers and reactors
    5.1 Determination of transformer load loss under
          distorted current loading
    5.2 Effect of geometrical arrangement of windings on
          their eddy current losses due to harmonics
    5.3 Loss in interphase transformers, current-balancing
          reactors, series-smoothing reactors and transducers
    5.4 Voltage drops in transformers and reactors
6 Tests for convertor transformers
    6.1 Measurement of commutating reactance and determination
          of the inductive voltage drop
    6.2 Measurement of voltage ratio and phase displacement
    6.3 Load loss test
    6.4 Temperature rise tests
Table 1 Connections and calculation factors
Annexes
A Determination of transformer service load loss at rated
    non-sinusoidal convertor current from measurements with
    rated transformer current of fundamental frequency
B Short-circuit test currents and load losses in transformers
    for single-way convertors (total loss injection)
ZA Normative references to international publications with
    their corresponding European publications
Figures
A.1 Cross-section of a winding strand
A.2 Terminal identification for winding connection Y yyO
A.3 Terminal identification for winding connection D d y

Covers the specification, design and testing of power transformers and reactors intended for integration within semiconductor convertor plants. Does not apply to transformers designed for industrial or public distribution of a.c. power generally.