Online Measurement Scheme and Solution for Frequency Response Characteristics of CVT

An online measurement scheme and an algorithm for solving capacitor voltage transformer (CVT) frequency response characteristics are proposed to solve the problem of the CVT not being able to measure harmonic voltage. Firstly, impulse excitation is applied through the carrier port of CVT to excite the impulse response of CVT. Then, by truncating the CVT secondary response signal sequence based on the principle of minimum fluctuation energy increment, and the frequency response characteristics of CVT are estimated based on iterative reweighted ridge regression. The algorithm can suppress the adverse effects of matrix sickness, measurement errors and abnormal samples on regression calculation. Finally, the simulation platform based on MATLAB and a field test verify the effectiveness of the proposed method.