T/CI 086-2022 Active

Scope: This document specifies the requirements for high-temperature superconducting on-board traction transformers applied to locomotives, including terminology, definitions, test items, and test methods. This document applies to on-board traction transformers for locomotives where both high- and low-voltage windings are made of high-temperature superconducting materials. Main technical content: - The windings are made of high-temperature superconducting materials and installed on electric locomotives or electric trainsets. Under the same frequency, they use the principle of electromagnetic induction to convert the AC voltage and current supplied by the traction network into the AC voltage and current required by the train traction system. - The cooling system uses physical methods to remove the heat generated by the AC losses of the superconducting traction transformer and system leakage heat, thereby maintaining the operating temperature of the superconducting windings at the design value. - The critical current of the superconducting windings is the maximum DC current that is considered to pass almost without resistance in the superconducting windings. Note: The critical current is a function of magnetic field strength, temperature, and stress. - The AC losses of the superconducting windings refer to the power loss in the composite superconductor due to time-varying magnetic fields or currents. Note 1: AC losses include the time-averaged hysteresis losses of the superconductor, the coupling current losses of the conductors, and eddy current losses. Note 2: Conventionally, AC losses also include the power loss in the composite superconductor due to externally applied transient magnetic fields or currents. - The total loss of the superconducting transformer is the sum of the no-load loss, load loss, and cooling system loss during operation of the superconducting transformer. - The loss of superconductivity of the superconducting windings refers to