Correção ativa do fator de potência em retificadores monofásicos de onda completa

Abstract

The design of robust electronic machines and equipment with high efficiency that preserves the quality of energy from the power grid has been one of the main goals of modern industry. Concern for the environment has led to developing increasingly compact and optimized devices for specific tasks. Many devices require direct current (DC) power and typically use conversion processes that transform the alternating current (AC) available in the power grid into direct current according to the load’s needs. This AC-DC conversion is achieved using a circuit known as a rectifier. The earliest rectifiers used only diodes in conjunction with a typically capacitive filter and were widely adopted due to their simplicity. However, the current drawn from the power grid is significantly distorted, reducing the power factor—an index that assesses the efficiency of the conversion process. Many modern devices hold certifications or comply with standards, such as the 80 Plus certification, which requires a power factor above 0.9 (1). This requirement is met through power factor correction strategies and active rectifiers that employ modern current control techniques, resulting in a sinusoidal current draw in phase with the power grid voltage and achieving a power factor close to unity. In this context, the objective of this work is to analyze active power factor correction mechanisms in single-phase rectifiers, as well as to study active rectifiers with a focus on controlling input current and output voltage. The results indicate that the rectifier with capacitive filter presented a power factor of approximately 0.498 and current peaks of 27.14 A, while the simulated Boost PFC converter achieved a power factor of 0.99, peak current of 5.69 A, and output-voltage regulation at 220 V.