New Testing Method of the Shielding Effect of Heavy Current Transformer With Shielding Coils

Design of equivalent coils for anti- interference testing of heavy current transformers

“…The two-segment testing coil design is firstly proposed in [11], as shown in the right diagram of Fig. 2.…”

“…In [11], a method is proposed to simplify the multi-phase interference into a stray field produced by a single large current, but still a large current source as well as bulky bus-bars are required in the testing [12][13][14]. On the other hand, the principle of shielding coils can also be applied, i.e., introducing a set of partial testing coils to generate an equivalent interfering magnetic field.…”

“…The method is referred to as "Non-uniformly Distributed Ampere-turns Method" [11], where the testing coils need much lower current to work and thus significantly ease the difficulty of the testing.…”

“…Previous works are mostly based on finite-element analysis (FEA) or experiments [4][5]15], which are accurate enough, but not efficient enough for such optimization-oriented analysis. In [11], an equivalent circuit method is used to determine the parameters of the testing coils, but the highly-simplified model is insufficient to certify a full-range magnetic equivalence in the core.…”

“…In section 2, an improved design method for the twosegment testing coil presented in [11] is introduced. Then, a new multi-segment testing coil configuration is proposed in section 3.…”