A DSP Based Optimal Algorithm for Shunt Active Filter Under Nonsinusoidal Supply and Unbalanced Load Conditions

Dept. of Electr. Eng., Indian Inst. of Technol., Mumbai
IEEE Transactions on Power Electronics (Impact Factor: 5.73). 04/2007; DOI: 10.1109/TPEL.2006.890001
Source: IEEE Xplore

ABSTRACT The use of power electronic circuits in a wide range of applications has resulted in distorted current waveforms in the power system. This results in nonsinusoidal voltage drops across the transformers and transmission line impedances, resulting in a nonsinusoidal voltage supply at the point of common coupling. Asymmetrical distribution of large, 1-phi loads further complicates the issue by causing imbalance in the line currents of the 3-phi system. Not only should this imbalance be compensated, other parameters, such as the current total harmonic distortion and the power factor should also be maintained as per the norms. However, the requirements of harmonic free current waveforms and good power factor, under nonsinusoidal voltage conditions, are contradictory to each other. Under these conditions, an optimum performance is the best one can achieve. This paper proposes a new scheme for balancing the currents and obtaining the best compromise between the power factor and current distortion under nonsinusoidal voltage conditions. The technique does not use p-q theory and does not require sequence transformation for power calculations, even though the current is unbalanced. All the details of this work are presented

  • [Show abstract] [Hide abstract]
    ABSTRACT: In order to get an optimum power factor in the load compensation under distorted supply voltages, a new control strategy is proposed in this paper. In this strategy, the conductance factors for the compensated load are evaluated for the specified source current total harmonic distortion (THD) limit. The performance of this method along with perfect harmonic cancellation (PHC) and unity power factor (UPF) strategies is evaluated on a distribution system model developed using PSCAD 4.2.1. The effect of selection of control strategy in damping the harmonic resonance, which is one of the main problems for harmonic propagation in the distribution system, is verified. The simulation results are presented to evaluate the performance of these strategies in load compensation and diminishing the harmonic propagation in the distribution system.
    Power Systems, 2009. ICPS '09. International Conference on; 01/2009
  • [Show abstract] [Hide abstract]
    ABSTRACT: The main objective of this present paper is the study of the shunt active power filter (APF) compensations capability for different perturbations in AC power system such as current unbalance, phase shift current and undesired harmonics generated by nonlinear load and/or by the power system voltage. This capability is determined by the maximum rate of the apparent power that can be delivered. This study is based on the definition of the effective apparent power as defined in IEEE 1459-2000 which was proved to be the suitable amount to be concerned in the design process of different devices.
    Archives of Control Sciences 01/2010; 20(1).
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents the decoupled recursive-least-squares (DRLS) technique for extraction of instantaneous synchronized symmetrical components under fault conditions in power grids. The proposed DRLS technique demonstrates outstanding robustness during faults, subsequent circuit breakers operation, and transmission line reclosing. The proposed DRLS technique also significantly reduces the computational burden of the conventional RLS technique for implementation on digital signal processors (DSPs). The performance of the proposed DRLS technique has been evaluated through presetting selected simulation results in MATLAB-Simulink software. DSP implementation of the DRLS technique also confirms considerable computational efficiency improvement in comparison with that of the conventional RLS technique. The DRLS technique also shows better efficiency in comparison with the enhanced phase-locked loop (EPLL) technique under highly distorted power system due to harmonics according to our implementation on two different R&D DSP platforms.
    IECON 2011 - 37th Annual Conference on IEEE Industrial Electronics Society; 01/2011


Available from