Braz de Jesus Cardoso Filho

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Voltage sag is the most important power quality problem. The classical solution to protect industrial processes against voltage sags is based on the use of a large series voltage compensator (SVC), such as the dynamic voltage restorer. Although the SVCs are a general solution, in most cases alternative measures should be checked before purchasing such an(More)
Belt conveyors constitute an efficient and economical way for minerals and heavy load transportation from mines to their destination, they serve vital process units whose success depends on continuous operation. To meet important operational requirements, modern high capacity conveyor systems are equipped with medium voltage variable-speed induction motor(More)
The aim of this paper is to present a method to analyze the dynamic of the charge in a ball mill. The method is based on the mill torque estimated from angular position and motor electrical signals. The estimated torque signal obtained from a Luenberguer velocity observer is bandpass filtered to isolate the mill-filling-related component. The(More)
Voltage sag is one of the most important power quality problems affecting sensitive industrial equipment. Control panels consist of one or several units of Programmable Logic Controllers (PLC), Contactors and Adjustable Speed Drives. These devices are all sensitive to voltage sags. When a voltage sag occurs, a contactor could trip or a PLC could reset while(More)
This paper presents a case study of a medium-voltage three-phase capacitor bank (CB) energization, based on an unsynchronized switching scheme using three independent pole vacuum switches simultaneously commanded. The motivations are cost reduction and simplification of the switching scheme. The maximum current and voltage peaks during transients caused by(More)