Ernesto Ruppert Filho

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This paper proposes a method of modeling and simulation of photovoltaic arrays. The main objective is to find the parameters of the nonlinear I–V equation by adjusting the curve at three points: open circuit, maximum power, and short circuit. Given these three points, which are provided by all commercial array datasheets, the method finds the best I–V(More)
This paper presents the analysis, design, construction and ac test results of low voltage single-phase resistive superconductor electrical current limiters. Two different types of resistive superconductor current limiter are presented: the first one is built with three concentric, cylindrical and helicoidal coils connected in parallel and the second one is(More)
A three-phase induction motor direct torque control laboratory set-up for simulation and experimental activities is presented in this paper. It includes both PI controllers and sliding-mode controllers and uses a sensorless method to estimate rotor speed. The subject of this set-up is to present to the students a simulation tool based on Matlab(More)
The control of the input voltage of DC-DC converters is frequently required in photovoltaic applications. In this special situation, unlike conventional converters, the output voltage is constant and the input voltage is controlled. This paper deals with the analysis and the control of the buck converter with constant output voltage and variable input.
The Direct Torque Control (DTC) with Space Vector Modulation (SVM) and Self-Tuning PI-Type Fuzzy (STPIF) controller is proposed. This controller determines dynamically the load angle between stator and rotor flux vectors and in consequence the electromagnetic torque necessary to supply the motor load. The rule base for STPIF controller is defined in(More)
This paper proposes a design and tuning method for a complex gain controller, based on the three-phase induction motor mathematical model complex transfer function to be used in the direct torque control at low speed which is a problem so far. The design and tuning of the complex gain is done by using the closed loop system frequency-response function.(More)
Switched reluctance generator (SRG) has been covered in several researches in the last two decades. These kind of machine is very promising for wind power application due to their low cost, high efficiency and high power density per volume. On the other hand, lots of researches are dedicated to the study and project of traditional SRG (radial flux). This(More)
The term Smart Grid has become a term to represent the benefits of a smart and sophisticated electrical grid, which can meet various social expectations related to sustainability and energy efficiency. The Smart Grid promises to enable a better power management for energy utilities and consumers, to provide the ability to integrate the power grid, to(More)