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ABSTRACT: This paper shows a new algorithm in the natural abc coordinates to calculate the current reference in a shunt active power filter. It modifies the Fryze's algorithm based on classical power theories for obtaining an optimal estimation in the current reference when the voltage in the utility is distorted. The aim of the method is twofold; first, to mitigate the harmonic components and second, to improve the power factor in the system blocking the reactive components. The feasibility of the algorithm in real-time applications has been tested with different waveforms and the results are compared by means of the total harmonic distortion in the grid current and the system power factor before and after the compensation. In addition, the results obtained in the experimental setup show the correct performance of the algorithm and demonstrate its easy implementation in industrial systems.
IEEE Transactions on Power Delivery 11/2007; · 1.35 Impact Factor
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H. Amaris
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ABSTRACT: Electrical utilities and system operators have specified in their grid codes that wind farms shall remain connected to the power system for voltage dips in their terminals. In this paper the application of power electronic systems for voltage dip mitigation is analysed.
Power Engineering Society General Meeting, 2007. IEEE; 07/2007
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ABSTRACT: This paper shows a new strategy to calculate the reference current in a power active filter used to mitigate harmonics injected by non-linear loads. The current is predicted with a Kalman filter a sampling period ahead to reduce and compensate the delay time effects caused by the acquisition times, the data processing and the performance of the filter. The validity of the algorithm is demonstrated by means of simulations in Matlab/Simulink. Several Kalman filters were studied and their capabilities compared to find out the best performance at the lowest computational cost.
Power Tech, 2005 IEEE Russia; 07/2005
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ABSTRACT: Wind turbines may have an important impact on power quality. Flicker is a more serious issue for fixed-speed wind turbines, because these turbines produce electric power following the variations of the incident wind. During continuous operation, wind variations will result in power fluctuations and consequently in voltage fluctuations. It is necessary to evaluate wind turbine flicker emission level, and traditionally time domain simulations have been used to perform the analysis. This paper presents a complete frequency domain model to study flicker produced during wind turbine continuous operation. The model includes a realistic wind speed model as observed by the wind turbine, and also a frequency domain induction generator model is presented. The frequency domain model is compared with a time domain model. The frequency domain approach, as shown in the paper, may be very useful for flicker analysis in electric networks.
IEEE Power Engineering Review 12/2002;
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ABSTRACT: Wind Energy Conversion Systems (WECS) produce fluctuating output power, which may cause voltage fluctuations and flicker. Flicker assessment in networks may be difficult, since its evaluation requires long computing time and special procedures to calculate the flicker severity index, Pst. A frequency domain method to study flicker propagation is presented. This method is based on propagation of frequency components from WECS output currents throughout the grid. In this way, a fast flicker analysis in a network of any size can be performed. An algorithm for flicker measurement in the frequency domain, which allows Pst calculation, is proposed. Several study cases were performed, and results are compared with time domain simulations, showing good agreement between them.
IEEE Power Engineering Review 06/2002;
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ABSTRACT: Wind energy conversion systems (WECS) may produce greater power
fluctuations than other forms of generation, resulting in voltage
fluctuations and flicker. This fact may become a serious limitation to
wind generation on weak networks. According to Standard UIE, for
quantifying flicker at the point of common coupling (PCC), and to obtain
the Pst parameter, it is necessary to measure the voltage for about 10
minutes. For this reason, time domain simulations require very long
solution times. In this paper, a frequency domain analysis method is
proposed, which allows to obtain the Pst parameter from the spectrum of
the RMS voltage fluctuation. Results of simulations of a wind turbine
MADE-AE41 in the time and frequency domains show good agreement
Harmonics and Quality of Power Proceedings, 1998. Proceedings. 8th International Conference On; 11/1998
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