XI Brazilian Power Electronics Conference

The paper illustrates the design of a white light solid state lamp, presenting a controlled quality of the emitted luminous flux in terms of both luminance and color temperature. Exploiting the same principle of color mixing adopted in RGB light sources, the designed fixture is based on three LED arrays implementing two primary color emitters (red and green) and a cool white light source. The regu... View full abstract»

The paper illustrates the design and operation of a line fed, solid state lamp driver based on the asymmetrical half bridge (AHB) flyback converter. The favorable converter's characteristics, in terms of soft-switching range and circuit complexity, allow it to operate at variable switching frequency in the range 300-450 kHz, supplying 6W to the load. The lamp is made up of 5 series connected high ... View full abstract»

In this article, a direct power control strategy for a doubly fed induction generation is presented. The control variables - d-axis and q-axis rotor voltages - are determined through a control system that consists of a neuro-fuzzy inference system and a Takagi-Sugeno fuzzy logic controller of first order. The input variables of the control system are the rotor speed, active and reactive power refe... View full abstract»

This paper deals with compensation algorithm schemes used in single-phase Uninterruptiple Power Supply (UPS) system, allowing harmonic suppression and sag/swell compensation of the input voltage. In addition, reactive power compensation and harmonic suppression of the input current are also carried out, resulting in an effective power factor correction. To compensate the input current and the outp... View full abstract»

This paper proposes a new dc-dc static power converter, designated Bidirectional Current-Fed Flyback-Push-Pull DC-DC Converter. Circuit operation, analysis, simulation, design example and experimental results are included in the paper. What distinguishes the proposed converter from the previous circuits is the existence of input and output inductors, which provides a significant reduction of both ... View full abstract»

This paper presents a direct power control strategy for a doubly fed induction generator using a Multilayer Perceptron controller. The controller generates the direct- and quadrature-axis rotor voltage signals without the necessity of current controllers. The proposed control strategy allows the converter that is connected to the rotor terminals to operate with constant switching frequency. Digita... View full abstract»

This paper proposes a wireless deadbeat power control scheme employing low density parity check coding for variable speed wind power generation (the wind industry is the huge driver behind the push for super-grids and cross-border infrastructure) to improve system robustness and reliability. The wind energy systems uses a doubly-fed induction generator and a deadbeat control. The performance impro... View full abstract»

In order to define the most appropriate power electronic converter topology for a specific application, several aspects must be analyzed, such as cost, efficiency, size, and volume of the chosen structure. However this may not be a trivial task in converters with high number of active and passive switches. This work introduces the concept of commutated power applied to six nonisolated dc-dc topolo... View full abstract»

In this paper is proposed modulation techniques for reducing leakage current in grounded photovoltaic panels for three-phase transformerless neutral point clamped inverters, which appear if there is no galvanic isolation between the photovoltaic system and the electric grid. The control is done by applying appropriate pulse width modulation techniques, that are capable of reducing the leakage curr... View full abstract»

This project presents 100W AC Module based on current fed push-pull converter applied to photovoltaic modules. The main goal is to demonstrate the functionality of the chosen converter topology for implementation on low power distributed generation from photovoltaic panels on the integrated module configuration. View full abstract»

The analysis and design of a single-stage three-phase high power factor rectifier, with high-frequency isolation and regulated load voltage are detailed in this paper. The circuit operation is presented, being based on the DC-DC SEPIC converter operating in the discontinuous conduction mode. This operational mode provides to the rectifier a high input power factor feature, with sinusoidal input cu... View full abstract»

A high step-up DC-DC converter based on the modified SEPIC converter is presented in this paper. The proposed topology presents low switch voltage and high efficiency for low input voltage and high output voltage applications. Two alternatives with and without magnetic coupling are analyzed. The magnetic coupling allows to increase the static gain with a reduced switch voltage. The theoretical ana... View full abstract»

Maximum Power Point tracking (MPPT) in photovoltaic (PV) systems may be achieved by controlling either the voltage or current of the PV device. There is no consensus in the technical literature about how is the best choice. This paper provides a comparative analysis performance among current and voltage control using two different MPPT strategies: the perturb and observe (P&O) and the incremen... View full abstract»

The Structural Health Monitoring - SHM method based on electrical impedance has been developed as a promising tool for structure failure identification in real time and is considered a novel non-destructive evaluation method. The piezoelectric - PZT impedance can be directly associated to the structure's mechanical impedance where de PZT is bonded. Assuming that the mechanical PZT properties do no... View full abstract»

This paper presents a procedure for high-level programming of a microcontroller using passivity-based control implemented in PFC (Power Factor Correction) boost converters. This is a non-conventional approach, where libraries are used to directly interface with the Texas's DSP 2812. Initially, the block diagrams that contain the control equations are constructed. Then, the codes are generated auto... View full abstract»

This work proposes an artificial neural network approach to estimate the induction motor speed. The induction motor has a great importance in many industrial sectors in which most control strategies are based on speed measurement of the motor axis. However, the direct measurement of this quantity reduces its robustness, compromises the driver system and control, besides increasing the implementati... View full abstract»

This paper presents a research about the harmful effects of partial shading on a photovoltaic panel. The analysis begins with the study of the electrical model of the solar cell and is extended to the module and the photovoltaic panel. The computational evaluations determine the relationship between the position of shade on the photovoltaic array and its electrical efficiency. An experimental phot... View full abstract»

This paper analyses the utilization of an energy regeneration circuit in a three-level NPC (Neutral-Point Clamped) voltage-fed inverter using a modified Undeland snubber. The regeneration circuit uses a QSC (Quasi-Square wave Converter) ZVS (Zero Voltage Switching) dc-dc auxiliary converter to restore the energy from the snubber capacitor to the dc bus. The regenerative circuit uses a single activ... View full abstract»

This paper presents a single stage three phase Buck-Boost AC-DC converter operating in continuous conduction mode (CCM). The converter operates with high power factor in wide input voltage range (60 - 140 VRMS line-to-neutral). It has three operations modes: Buck, Boost and a combination of both, named Buck+Boost. The original topology, operation stages, mains waveforms and equations fo... View full abstract»

This paper presents novel simulation tools to assist the lecturers about learning processes on renewable energy sources, considering photovoltaic (PV) systems. The PV behavior, functionality and its interaction with power electronic converters are investigated in the simulation tools. The main PV output characteristics, I (current) versus V (voltage) and P (power) versus V (voltage), were implemen... View full abstract»

This work deals with power quality analyses related to the effect of different drop transfer modes in Gas Metal Arc Welding (GMAW) processes. The different drop transfer modes of GMAW process could be classified into: short-circuiting, globular, spray and pulsed. The correct choice of GMAW parameters is essential for optimal performance of the welding process. On the other hand, optimal parameters... View full abstract»

This paper presents evaluations among the most usual MPPT techniques, doing meaningful comparisons with respect to the amount of energy extracted from the photovoltaic panel (PV) (Tracking Factor - TF) in relation to the available power, PV voltage ripple, dynamic response and use of sensors. Using MatLab/Simulink® and DSpace platforms, a digitally controlled boost DC-DC converte... View full abstract»

This paper presents an electronic AC power system, with power factor correction, to drive and control the current of LEDs (Light Emitting Diodes). The power factor correction and the controlled DC bus voltage are performed by a Buck stage. A transistorized linear regulator coupled to the Buck will drive and control the LEDs. A study is presented considering the variation of the current ripple of L... View full abstract»

This work presents a stability evaluation for a single-phase boost PFC converter employing digitally implemented input current self-control to achieve close to unity power factor. Both analog and digital approaches for the proportional compensator are studied and the effects of transport delays found in digital controllers are considered. It is verified that the use of a digital proportional contr... View full abstract»

Most design techniques for power factor correction converters considers the cascade control technique assumes that output voltage ripple is removed from the feedback path using a compensator with low-pass characteristic. This strategy allows power factor correction and output voltage regulation but result in voltage loop with a poor dynamic performance. In order to mitigate this problem many desig... View full abstract»