tailieunhanh - Kalman Filter_2

Tham khảo sách 'kalman filter_2', công nghệ thông tin, kỹ thuật lập trình phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Electrical Engineering 16 Estimation of Electrical Power Quantities by Means of Kalman Filtering Alberto Pigazo and Victor M. Moreno University of Cantabria Spain 1. Introduction The presence of non-linear loads and the increasing number of distributed generation power systems DGPS in electrical grids contribute to change the characteristics of voltage and current waveforms in power systems which differ from pure sinusoidal constant amplitude signals. Under these conditions advanced signal processing techniques are required for accurate measurement of electrical power quantities. The impact of non-linear loads in electrical power systems has been increasing during the last decades. Such electrical loads which introduce non-sinusoidal current consumption patterns current harmonics can be found in rectification front-ends in motor drives electronic ballasts for discharge lamps personal computers or electrical appliances. Current harmonics reduce the efficiency of low and medium voltage electrical grids Dugan et al. 2003 . It must be also considered that renewable energy sources in electrical grids can also deteriorate the electrical power quality. For instance wind turbines can introduce flickering Larson 2000 and PV systems due to solar radiance variations generate variable output power. Moreover such resources especially in low-voltage systems change their status grid connection or disconnection continuously contributing to the electrical system instability. Diverse approaches can be applied to characterize electrical signal waveforms in real-time windowed or recursive Fourier transforms wavelets artificial neural networks ANN Bollen Gu 2006 . Kalman filtering can be applied to estimate electrical quantities in power systems such as voltage and or current magnitude grid balance and or frequency. The obtained signal measurements can be employed for revenue purposes electrical grid characterization and or active compensation of power system disturbances. This chapter