Improved sampled value adjustment algorithm increasing measurement precision of smart substation PMU

An improved adjustment algorithm of sampled value is proposed to increase the measurement precision of smart substation PMU,which applies the cubic spline interpolation and time scale transformation to realize the seamless join of the values sampled by process bus with the PMU algorithms. The spectrum leakage error of DFT algorithm due to system frequency deviation with fixed frequency sampling at process level is thus reduced and the influence of transmission data loss on the precision of PMU algorithm is also weakened. The proposed algorithm is simulated with MATLAB in smart substation environment and the results demonstrate that it is immune to the frequency deviation and transmission data loss and can guarantee precision of PMU measurement.