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The objective of this paper is to propose a new approach for designing a passive LC filter of the full-bridge rectifier by using genetic algorithms (GAs). The performance of the cost-effective passive LC filter for a constant load depends on the appropriate inductor and capacitor selection. Several design methods are reviewed and a novel design methodology using GAs is proposed in this paper. By using the proposed GA program, designer can quickly find appropriate parameter values to meet the desired circuit performance. Experimental results show that an appropriate combination of the inductor and capacitor selected by the proposed GA program can meet the desired power quality requirement. Different cases of design examples are shown in this paper to verify the performance of the proposed design methodology. Index Terms--Genetic algorithms (GAs), harmonic distortion, passive LC filters, power-factor correction.

This paper presents a current-sensorless active rectifier specifically designed for low-cost applications. Both the control and the modulation use fuzzy logic. A simple model of the system is given in order to explain the current feedforward control using fuzzy logic and the fuzzy-logic-based modulation, then, the new algorithm is analyzed looking for high performance even using small passive elements and low switching frequency. Performance are compared with those of a closed-loop proportional-plus-integral (PI)-based rectifier with space-vector modulation (SVM). This comparison has been carried out either considering the whole systems or a combination of their components (PI control + fuzzy modulation or fuzzy feedforward control + SVM). The results show that even without current sensors, the low-frequency distortion of the line currents and the dc voltage oscillations produced by the proposed system are very limited, ensuring performance similar to those of PI-based closed loop active rectifiers. Index Terms--Feedforward systems, fuzzy logic control, power-factor control, switch-mode rectifiers.