J. Doval

Shunt active power filter with harmonic current control strategy

This paper presents a single phase shunt active power filter for compensating the power factor and harmonics currents generated by two nonlinear loads, an AC controller with resistive load, and a rectifier with an inductive load. The topology of the filter is based on a single phase inverter with four IGBTs. The filter current is forced to follow a reference; this reference current must be the difference between the sinusoidal input current in phase with the sinusoidal voltage supplying the load and the load current; for calculating the reference current a frequency-independent method has been used. The calculus of the reference current and results of simulation are presented; finally experimental results obtained from a prototype confirm the feasibility of the proposed system.

E-learning system for power electronics converters

A multimedia and interactive system to help teaching power conversion techniques for AC/DC, DC/AC and AC/AC is described as a tool for both teachers and students. The tool include many different suitable topologies for the aforementioned power systems. In each different topology, the user can select among types of loads: resistive, inductive, capacitive and combinations. Firing angles and modulation schemes can also be selected to show different behavior of the topologies. Some values are selected by introducing the desired value, and remain fixed during simulations while other values can be dynamically adjusted with sliding rules during simulations. During the simulation the circulating current direction and the state of semiconductor switches is shown, by means of changing colors. The multimedia system includes documentation on all the subjects, showing basic concepts and equations, in pdf format and links to industrial manufacturers. One of the main contributions is that all the system is in Spanish language, becoming useful for classroom and laboratories duties without the need of translation. Once finished with the simulations, the students can auto evaluate themselves with an automated test set. This feature helps the students to establish the knowledge level acquired after employing the multimedia tool.

FPGA implementation of a fuzzy controller for automobile DC-DC converters

The design of synchronous multiphase DC-DC converters for automobile applications is now a very active field, because the automotive industry forecast that future power demands inside a car will oscillate between 2.5 kW and 3.5kW, keeping a dual system of 42/14V batteries. The design of controllers for the optimal behavior of such converters is a very delicate task. In this paper, an optimized fuzzy control algorithm has been developed to control a synchronous multiphase converter of 1.6kW. First, the fuzzy control algorithm is designed and verified, together with a non linear model of the converter power stage, by means of Matlab and Simulink. Then, the fuzzy controller hardware is developed through Xilinx System Generator for Simulink, and implemented in a Spartan 3 FPGA to achieve a real-time controller

An approach to real behaviour modeling for traction lead-acid batteries

At the present time, the batteries are the main obstacle in the race toward the total development of the electric vehicles. In this article we present a PSPICE model for lead-acid batteries of traction that represents an approach of the real behavior of these so that it can be analyzed directly from the PSPICE environment. This model is flexible and can be adjusted in function of the type of electrochemical battery.

Design, Analysis and Modeling of an Optimized Fuzzy Control Algorithm for Synchronous Multiphase DC-DC Converters in Automotive Applications

The design of synchronous multiphase DC-DC converters allows improvements of the characteristics of high power systems. The automotive industry forecast that future power demands inside a car will oscillate between 2.5 kW and 3.5kW, keeping a dual system of 42/14V batteries. In this paper, an optimized fuzzy control algorithm has been developed to control a synchronous multiphase converter of 1.6kW for dual voltage architecture in future vehicle applications. The proposed optimized fuzzy control algorithm is analyzed and simulated together with a non lineal model of the power stage, by means of Matlab and Simulink. This simulation platform also integrates tools for a future implementation of the controller embedded in a FPGA. The main contribution of this work is the implementation of an optimized fuzzy algorithm of control that can be used independently of the number of phases of the converter, making it suitable to be applied in a wide range of high power applications. This algorithm has been designed having in mind the goal of developing a real-time FPGA-based controller, so the complexity has been reduced to a minimum. Hybrid vehicles, aerospace and naval industry power systems can also benefit from the development of this algorithm.

DMX512 Controller for High Brightness RGB LED Matrix

DMX512 is the standard protocol used by lighting equipment in theatrical and entertainment data distribution systems. This paper describes a complete hardware and software solution for driving a high brightness 70 pixel RGB LED matrix from a computer and synchronized with environmental music, in addition to multiple running modes and possibilities achieved. Further possibilities of the developed device running as universal automation controller, are also mentioned.

Remote System of Design and Test of DC-DC Converters

The increasing interest in remote test and experimentation has allowed the incorporation to the educative system of new tools that improve the classic methods of education. In the field of the Power Electronics, the possibility of access of the engineering student through the development of this type of tools to equipment generally of high cost, and therefore of low availability in the educational laboratories, is very important. This work shows a Remote System of Design and Test of DC/DC Converters (RSDTC) that can be used either locally or remotely. The developed system is based on a test bench manufactured by Hewlett-Packard. Taking as its starting point this equipment, a software application has been developed using the visual programming language “LabVIEW”. This programming tool combined with CGI (Common Gateway Interface), allows the developed analysis system to be executed remotely using a web browser.

Considerations of DSP controlled VSC based STATCOM

The paper presents the analysis of the PWM static VAr compensator (STATCOM) when the pole assignment control method is used in order to improve the dynamic response. The STATCOM is based on a conventional six-switch bi-directional voltage source converter topology using insulated gate bipolar transistors (IGBTs). The sinusoidal pulse width modulation technique is used to control the converter output voltage (amplitude and phase). Two references DC voltage for DC voltage control are using and the trade-off between the value of the DC capacitor and the ripple voltage and the systems transient response time are investigated. The control system, has incorporated VAr calculator and synchronization, which, together the control algorithm, has been implemented on a digital signal processing (DSP) board, to achieve excellent overall performance. Experimental results for both leading and lagging VAr compensation, along with changes between them, confirm the good performance and the flexibility of the developed prototype.

Improving pulse width modulation in order to get a silent AC motor

When using sinusoidal PWM for controlling inverters feeding induction motors, the inverter operates with fixed switching frequency. If this frequency is under 20 kHz, the motor emits noise which is annoying for human beings. One solution is to use a triangular waveform with a frequency higher than 20 kHz, but this will result in increased losses in the electronic devices and the motor. Another solution is to spread out the harmonic spectrum. This paper describes two strategies for decreasing the acoustic noise of an induction motor by reducing the concentration of harmonic energy in distinct tones. The strategies implemented are generation of a triangular waveform with randomized frequency for each fixed subcycle and for each random subcycle of the output frequency. Simulation and experimental results show the absence of acoustic noise concentrated at specific tones. The motor emits a whistling sound which is not annoying to human beings.

Random modulation in inverters feeding induction motors

This paper proposes a random pulse width modulation scheme, where the frequency of the triangular waveform is generated in a random way, for decreasing the acoustic noise of an induction motor. Two different strategies have been implemented: generation of a triangular waveform with randomized frequency for each fixed subcycle and for each random subcycle of the output frequency.