抄録
Severe Transient Recovery Voltage (TRV) after the current interruption may appear when a fault occurs in the immediate vicinity of a power transformer without any appreciable capacitance between the transformer and the circuit breaker. These faults are called Transformer Limited Fault (TLF) that may cause higher Rate-of-Rise of TRV (RRRV) than the standard values specified for terminal fault test duties T10 and T30 of IEC 62271-100. TRVs for TLF conditions with large capacity and high voltage shell type power transformer were measured by the capacitor current injection method. The impedance frequency responses were also measured by the Frequency Response Analysis (FRA) and then TRVs were reproduced with the simplified transformer model consisting of a series connection of parallel circuit of inductance, capacitance and resistance whose parameters were evaluated by the FRA measurements. The reproduced TRV showed good agreement with the measured TRV even though deformation from a sinusoidal shape wave was observed due to superposition of higher frequency components on the TRV.
