A two-sample algorithm for three-phase voltage parameters estimation under abnormal grid conditions

Accurate estimation of grid voltage parameters such as amplitude, phase angle and frequency is crucial for advance control and protection in power systems. There are different estimation techniques in the specialized bibliography, so the selection for their implementation involves analyzing a trade-off of operating characteristics such as accuracy, response time or complexity. This paper proposes a three-phase estimation algorithm with high fidelity performance during abnormal grid conditions. The proposed algorithm combines a new Two -Sample Sequence Extractor (TSSE) and a Recursive Least Mean Square (RLMS) frequency estimator in a mutual feedback mode to improve its operation. To estimate the amplitude and phase of the positive and negative sequence components, the TSSE performs a linear approximation between two voltage samples. Furthermore, a slide window approach RLMS is used to estimate the system's frequency. Simulation and experimental results are presented to analyze and validate the performance of the TSSE-RLMS. In addition, the proposed algorithm is compared with other four kinds of estimation methods under different grid conditions.