Implementation of the supercapacitor-assisted surge absorber (SCASA) technique in a practical surge protector

Their combination of large continuous energy ratings and very large time constants allows supercapacitors to be used in surge protection circuits. This fact, supported by recent research publications and laboratory tests, has assisted the authors to propose a new surge protection circuit topology known as the supercapacitor-assisted surge absorber (SCASA). This technique utilizes a multi-winding transformer, common surge protector devices such as metal oxide Varistors (MOV) and/or semiconductor types combined with a supercapacitor sub-circuit to absorb part of the surge energy usually expected to dissipate within the MOV or the semiconductor. The paper presents design details and test results for a differential mode surge protector based on the SCASA technique where the test device was subjected to lightning-type surges defined in international standards for Class-A and Class B type protectors. The performance of a prototype based on Class-B waveforms of up to 6.6 kV surges generated from a lightning surge simulator are discussed in the paper. Its performance is compared with two commercially available surge protectors.