Improvement of Current Transformer Accuracy by Digital Compensation Technique

Current transformer error compensation unit (CTECU) is developed which is specially intended for providing compensation to all types of measurement current transformers (CTs). The proposed CTECU is based on determination and application of correction coefficients, which are computed by the ratio and phase angle errors data provided by CT manufacturer. Analytical foundation is effectively expressed along with the development of CT error compensation algorithm. CTECU is implemented online in laboratory on 1.0 and 0.5 accuracy class of CTs. The experimental performance is found satisfactory under various operating conditions.