Study on the Improved Transformer Protection Scheme Based on The OCT

Abstract

This paper presents a new scheme for transformer differential protection based on the OCT. The scheme can operate reliably when internal faults occurred and do not operate in the condition of external faults, inrush and overexcitation. This scheme combines harmonic restraint and blocking methods with dc content blocking. In this paper, the digital signal processor (DSP) is applied to improve computation and render fast protection feasible. The novel transformer protection system interface construction, hardware structure, software algorithm are discussed. Performance analysis shows its has distinguish advantages over the traditional transformer protection