PWM Techniques Research Papers - Academia.edu (original) (raw)

In this paper, two topologies are presented for solar PV system, namely voltage lifting ZSI and voltage lifting Improved ZSI. These proposed inverters possess very high voltage boost. By replacing the middle diode in one of the switched inductor (SL) cell of SL-ZSII2SL-qZSI with capacitor (Cvd high voltage gain can be obtained and also number of L, C and diodes gets reduced, which reduces weight, space and cost of the system. Very small shoot through duty cycle results in high voltage boost, thus efficiency can also be increased. Proposed topologies are analyzed in the steady state and their performances are validated using simulated results obtained in MATLAB/Simulink. This paper presents operating principles, analysis and simulation results, and compares them with SL ZSII2SL-qZSI. Keywords-ZSI, qZSI, VL-ZSI, VL-Improved ZSI, SL-ZSI and 2SL-qZSI.

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- Z Source Inverter, Photovoltaic Solar Systems, PWM Techniques

Pulse width modulation (PWM) is used to generate pulses with variable duty cycle rate. The rapid rising and falling edges of PWM signal minimises the switching transition time and the associated switching losses. This paper presents a DC motor speed controller system using PWM technique. The PWM duty cycle is used to vary the speed of the motor by controlling the motor terminal voltage. The motor voltage and revolutions per minutes (RPM) obtained at different duty cycle rates. As the duty cycle increases, more voltage is applied to the motor. This contributes to the stronger magnetic flux inside the armature windings and the increase the RPM. The characteristics and performance of the DC motor speed control system was investigated. In this paper, a PIC microcontroller and a DC-DC buck converter are employed in the DC motor speed controller system circuit. The microcontroller provides flexibility to the circuit by incorporating two push button switches in order to increase and to decrease the duty cycle rate. The characteristics and performance of the motor speed controller system using microcontroller was examined at different duty cycle rate ranging from 19% to 99%.

- by MGES Journals
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- Microcontrollers, Dc Motor, Dc-Dc Converters, Pulse Width Modulation

Neste projeto pretende-se utilizar os conceitos adquiridos na área dos sistemas digitais e sistemas eletrónicos embebidos, e utilizando o Microcontrolador PIC16F628A, desenvolver um projeto prático para possibilitar o desenvolvimento dos conhecimentos adquiridos.
O projeto que se desenvolveu permite realizar o comando de dois semáforos luminosos (um para a saída de carros de uma garagem e outro para possibilitar controlar o avanço de peões numa passadeira) e de uma cancela (através de PWM – Pulse Width Modulation).
As indicações luminosas para carros e peões possuem 2 leds cada um (um vermelho e outro verde), possibilitando assim a paragem (vermelho) ou o avanço (verde) respetivamente, quer se trate de um carro ou de um peão.
Associado ao sistema está também um display BCD/7Segmentos que mostra o número de vezes que o peão carregou no botão de pressão – BP - existente (display reiniciado com o valor zero ao passar o valor decimal 9).
A implementação foi realizada utilizando o Software MPLAB® IDE v8.88 da Microchip© e os esquemas apresentados foram elaborados utilizando o ISIS Profissional da Labcenter© Electronics v. 7.7 SP2 (Build 9089).

Pulse Width Modulation (PWM) is a common technique
used in many different applications of 3-phase voltage source
inverter. This paper presents a pulse generation of SPWM
technique for three-phase voltage source inverter using
dsPIC33FJ16GS402 controller. Logic for implementing SPWM
technique is described. The carrier signal frequency is designed
for 20 kHz with varied modulation index (Ma) and the
fundamental signal frequency is designed for 50Hz. Simulation
results of controller circuit, carried out in PROTEUS simulator
are shown, Also mentioned in developed driver and controller
cards in this paper. An experimental result presented in this
paper shows the effectiveness of pulse generation Technique.

In this paper we present a modulator for an all-digital pulsewidth modulated (PWM) transmitter based on switching amplification. In this approach, each symbol is represented by a sequence of pre-computed PWM pulse widths stored in a table that results in reduced Error Vector Magnitude (EVM), achieving low distortion with a reduced pulse-rate. The modulator is implemented in a field programmable gate array
(FPGA) device. The performance of this approach is compared to standard uniform PWM modulator. Measurements using 64-QAM signals show a reduction of EVM values from 11.61% (−18.7 dB) for uniform PWM to 2.41%(−32.4 dB) for the proposed approach.

In this paper the Synchronous Reference frame PI-based control method for generating the reference signals for the Voltage Source Converter of Shunt Active Power Filter (SAPF) is presented. The method relies on the performance of the Proportional-Integral (PI) controller for achieving the best control performance of the SAPF. To improve the performance of the PI controller, the feedback path to the integral term is introduced to compensate the winding up phenomenon due to the integrator. Using Reference Frame Transformation, reference signals were transformed from c b a   stationery frame to q d   0 rotating frame. Using the PI controller, reference signals in q d   0 rotating frame were controlled to get the desired reference signals for the Pulse Width Modulation. Using MATLAB/SIMULINK, the 5 th , 7 th , and 11 th harmonics were used to test the proposed Active Power Filter with improved PI controller resulting in harmonic content down to 3.87%.

- by Ankit Patel
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- Power Quality, Power Supply, Harmonic Elimination, PWM Techniques

In this paper, different sinusoidal pulse width modulation (SPWM) control strategies of multilevelflying capacitor inverter are presented. Three control strategies are studied; the triangular multicarrier SPWM, thesaw tooth multicarrier SPWM and the sinusoidal multicarrier SPWM. This work begins with a presentation of theflying capacitor inverter. Then a paragraph that gives a brief review of the triangular multicarrier SPWM, the sawtooth multicarrier SPWM and the sinusoidal multicarrier SPWM. A comparison between the three SPWM controlstrategies is established based on the simulation results. The comparison objects are the root mean square rms ofthe output voltage and the total harmonic distortion (THD). The results obtained demonstrate that the sinusoidalmulticarrier SPWM is better than the saw tooth multicarrier SPWM and the triangular multicarrier SPWM.Simulations are carried out by PSIM program.

In an electric drive vehicle, the available voltage on
a DC-link is limited, and so the inverter output voltage and,
consequently, the line motor maximum speed are limited. The
fundamental voltage of the inverter output is increased
approximately 27% using a square wave switching pattern
instead of a sine wave switching pattern. However, this pattern
can only be used at high speeds, and at lower speeds a pulse width modulation pattern should be used. In order to achieve proper control, the switching pattern should be changed seamlessly. In the present paper, a new pulse width modulation (PWM) scheme for single-mode seamless control of Vernier motors is proposed.
In the proposed scheme, the reference voltage is modified to
change the switching pattern continuously so that the voltage
changes smoothly from a high-frequency pattern to a square
wave and voltage discontinuity does not occur. Experimental
results reveal that the inverter-switching pattern changes
smoothly from a sinusoidal pulse width modulation pattern to a
square wave pattern, and so seamless control from the constant torque region to the constant-power region, and vice versa, is achieved. Since the proposed scheme is a single-mode control, it is much simpler than current technologies, which are based on multi-mode controllers. Also the proposed method has a lower total harmonic disturbance (THD) as well as a lower harmonic distortion factor (HDF) compared to some existing methods.

- by ahmad ghaderi
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- Motor Control, Electric Vehicles, Electric motor drives, PWM Modulation Converters

—Solar photovoltaic is one of the most promissing technologies for the non-carbon based electricity production. However, solar photovoltaic modules are both large and have a very low efficiency for producing the necessary voltage for an end-user applicaton. Using high efficient power electronics in power generation, e.g. step-up-down DC/DC converters could eliminate this demerit. The control features of such a new type of converter are discussed in this paper. The switching structures of a DC drive fed by the presented converter are analyzed, feedforward control based on solving the limit cycle is designed and some validated experimental results are given.

- by Dhaval Vyas
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- Power Quality, Power Supply, Harmonic Elimination, PWM Techniques
- by Ankit Patel
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- Power Quality, Power Supply, Harmonic Elimination, PWM Techniques
- by Mahesh Patel
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- Power Quality, Power Supply, Harmonic Elimination, PWM Techniques

This article presents the improvement of a PWM technique, called Space Vector PWM (SVPWM), using an Artificial Neural Network (ANN) to minimize the mathematic complexity involved with the SVPWM. The latter is a pulse-width modulation technique that is wide implemented to control AC electric motors. The results obtained from this research work will be used for further implementation of artificial intelligence techniques to control electric vehicle powertrains. Matlab is implemented for the ANN design and Labview for the FPGA programming and implementation.

- by Arturo Molina
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- Electrical Motors, Artificial Neural Networks, PWM Techniques