Use of Second Generation HTS Wire in Filter Inductor Coils

AMSC´s process for manufacturing Second Generation (2G) YBCO High Temperature Superconductor wire provides the flexibility to engineer practical 2G conductors with various architectures. For applications with high frequency ac components, a stainless steel stabilizer is used to minimize eddy current losses. An example of such an application is the so-called Buck Inductor, a filter inductor carrying a DC current onto which a 5 KHz ac current is superimposed. Previously we reported on the development and initial testing of the first 2G HTS toroid for this application. We demonstrated a strong reduction of the ac losses with a DC bias current. In this work, we present results on a toroid using a different double pancake design with better cooling. This design allows operation of the double pancake in liquid nitrogen at high frequencies without heating effects.