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This study presents a low-cost thyristor-controlled LC compensator scheme for the improvement of overall power quality in the distribution system. The parameters of the compensator have been designed and optimal triggering angles for thyristor switching have been obtained for reducing the unbalanced condition and harmonic injection at a high power factor. Compared to the traditional static VAr compensator schemes, the proposed technique can significantly reduce the harmonic injection into the system. The particle swarm optimization technique has been applied to compute the optimal triggering angles, and different aspects of the power quality factor have been assessed through rigorous simulations. Power quality assessment has been further validated through an experimental setup in the laboratory. Finally, a comparison of the proposed scheme with other similar schemes has been carried out to highlight its efficacy. [ABSTRACT FROM AUTHOR]

Among the existing power quality problems, the reactive power compensation plays a key role once it helps to maintain the system stability and increases the efficiency. Currently, there are many solutions for reactive power compensation, which unfortunately present a wide variety of problems as large inrush currents, non-continuous compensation and harmonics injection in the system. The application of devices like static VAr compensator, static synchronous compensator or unified power flow controller has demonstrated to be an effective solution for reactive power compensation. However, it is important to note that these options are rarely used in distribution systems by companies that prefer to assimilate the drawbacks of switched capacitor banks instead of investing in more expensive, sophisticated and complex solutions. Despite the large number of proposed devices in distribution systems, there is a lack of solutions with emphasis on cost reduction. Therefore, this paper presents a new topology for reactive power compensation and voltage control in distribution systems. The proposed topology has several interesting features as reduced switching losses, small capacitors and simple control scheme. In addition, the proposed solution uses already existing capacitor banks which makes possible its usage in distribution companies with minimum modifications. Experimental results have been obtained on a 6-kVA prototype to demonstrate the feasibility of the proposed solution. [ABSTRACT FROM AUTHOR]

In this paper, a new continuously and linearly controlled capacitive static VAR compensator is proposed for the automatic power factor correction of inductive single phase loads in 220V 50Hz power system networks. The compensator is constructed of a harmonic-suppressed TCR equipped with a new adaptive current controller. The harmonic-suppressed TCR is a new configuration that includes a thyristor controlled reactor (TCR) shunted by a passive third harmonic filter. In addition, the parallel configuration is connected to an AC source via a series first harmonic filter. The harmonic-suppressed TCR is designed so that negligible harmonic current components are injected into the AC source. The compensator is equipped with a new adaptive closed loop current controller, which responds linearly to reactive current demands. The no load operating losses of this compensator are negligible when compared to its capacitive reactive current rating. The proposed system is validated on PSpice which is very close in terms of performance to real hardware. [ABSTRACT FROM AUTHOR]