Generalized Harmonic State Estimation: An Approach Considering Measurement and Parameter Errors

Harmonic state estimation (HSE) is an useful technique for determining harmonic voltages and currents in electric power systems based on synchronized measurements and network impedances parameters. However, measurements and parameters data can be corrupted by gross errors yielding unsatisfactory estimation results. Despite recent methods have been proposed for HSE in power systems, there are few works considering both harmonic state variables and parameters estimation. In order to solve this problem, this paper presents a generalized harmonic state estimation considering uncertain network parameters and synchronized measurements. In the proposed approach, harmonic voltage and current phasors are obtained by measurement units allocated along the system. Network parameters, such as line and load impedances, are treated as inequality constraints in an optimization problem formulation considering both system state variables and parameters to be determined by the proposed HSE. The main contribution of this research paper is the use of a deterministic approach for estimating both harmonic state variables and parameters with reduced estimation errors when compared with the traditional weighted least squares (WLS) technique. Computational simulations are carried out using the IEEE test systems and results are also validated using RSCAD (Real-Time Simulation Software Package) software.