Influence of Magnetic Field Generated by Terminal Current on Critical Current of DC HTS Cable Conductor With Large Current Capacity

DC HTS cable has attracted more and more attention in recent years due to its high efficiency in electric power grid and some locations with large current and short distance. If it is applied in the power transmission with current lower than 2 kA, the magnetic field at the position near the termination is usually neglected. Conventionally, most of the current lead is perpendicular to the cable conductor; the magnetic field generated by the current lead may affect the local critical current of the cable, particularly near the termination where the magnetic field is the superposition of the magnetic field created by the current lead and the cable conductor when the transport current is large. There are few papers calculating the influence of external magnetic field on the HTS cable by taking the current lead into account. This paper describes a method for calculating the influence of magnetic field created by the terminal currents on the critical current of the cable conductor. Based on the proposed method, two types of DC HTS cable by conventional design with large current capacity are analyzed, which confirms that terminal influence cannot be neglected when the cable carries large current. This method can also provide a useful reference when designing an HTS cable.