Pulse Width Modulation Signal Research Articles

AC PWM Control System in Induction Motor using Microcontroller

The demand for efficient and precise control of induction motors has led to the development of advanced control systems, among which AC PWM (Pulse Width Modulation) stands out as a prominent technique. This project focuses on the design and implementation of an AC PWM control system for an induction motor utilizing a microcontroller. The system employs a microcontroller to generate PWM signals, controlling the power electronics responsible for modulating the voltage supplied to the motor. The report details the architecture, components, and methodology employed in the project. A comprehensive discussion on the PWM control algorithm, motor drive circuitry, and sensor integration is presented. The microcontroller programming and experimental results showcase the effectiveness of the proposed system in achieving precise control over motor speed and efficiency. The challenges faced during the project are discussed, along with the corresponding solutions implemented. The report concludes with a summary of achievements and suggestions for future enhancements. Overall, this project contributes to the field of motor control systems, offering a reliable and efficient solution for induction motor control through AC PWM with microcontroller integration

An Optimization Algorithm for Embedded Raspberry Pi Pico Controllers for Solar Tree Systems

Solar photovoltaic (PV) systems stand out as a promising solution for generating clean, carbon-free energy. However, traditional solar panel installations often require extensive land resources, which could become scarce as the population grows. To address this challenge, innovative approaches are needed to maximize solar power generation within limited spaces. One promising concept involves the development of biological tree-like structures housing solar panels. These “solar trees” mimic the arrangement of branches and leaves found in natural trees, following patterns akin to phyllotaxy, which correlates with the Fibonacci sequence and golden ratio. By adopting an alternative 1:3 phyllotaxy pattern, three solar panels can be efficiently arranged along the stem of the solar tree structure, each rotated at a 120-degree displacement. Optimizing the performance of solar trees requires effective maximum power point tracking (MPPT), a crucial process for extracting the maximum available power from solar panels to enhance the overall efficiency. In this study, a novel metaheuristic algorithm called horse herd optimization (HHO) is employed for MPPT in solar tree applications. Moreover, to efficiently manage the generated power, a cascaded buck–boost converter is utilized. This converter is capable of adjusting the DC voltage levels to match the system requirements within a single topology. The algorithm is implemented using MATLAB and embedded within a Raspberry Pi Pico controller, which facilitates the generation of pulse-width modulation (PWM) signals to control the cascaded buck–boost converter. Through extensive validation, this study confirms the effectiveness of the proposed HHO algorithm integrated into the Raspberry Pi Pico controller for optimizing solar trees under various shading conditions. In essence, this research highlights the potential of solar tree structures coupled with advanced MPPT algorithms and power management systems to maximize solar energy utilization, offering a sustainable solution for clean energy generation within limited land resources.

Spectrally tunable light source based on deep neural network model

A spectrally tunable light source based on deep neural network (DNN) model is proposed in this work, which can reproduce arbitrary spectra accurately and rapidly. After calculating the scale factors using the trained DNN model, the target spectrum can be reproduced by regulating the combined monochromatic LEDs based on the pulse width modulation (PWM) signal with corresponding duty cycle. The standard solar spectrum and measured natural spectra at different times are reproduced using the proposed spectrally tunable light source. It is demonstrated that there is a good agreement between the target spectra and the corresponding reproduced spectra, with a fitted correlation index of above 0.9. Furthermore, the proposed spectrally tunable light source is able to transform spectrum at a frequency higher than 25 Hz and occupies only 750 KB memory space. As a result, the proposed spectrally tunable light source system can offer a high accuracy, fast speed and low cost approach to the development of specially light sources.

Nonlinear recurrence analysis of piezo sensor placement for unmanned aerial vehicle motor failure diagnosis

This paper is focused on the diagnostics of multicopter UAV propulsion system, in which the temporary transient states occur during operation in faulty conditions (eg. not all motor phases working properly). As a diagnostic sensor, the piezo strip has been used, which is very sensitive to any vibrations of the multi-rotor frame. The paper concerns the precise location of the sensor for more effective monitoring of the propulsion system state. For this purpose, a nonlinear analysis of the vibration times series was carefully presented. The obtained non-linear time series were studied with the recurrence analysis in short time windows, which were sensitive to changes in Unmanned Aerial Vehicle motor speeds. The tests were carried out with different percentage of the pulse width modulation signal used for the operation of the brushless motor and for different locations of the piezosensor (side and top planes of the multicopter arm). In the article, it was shown that the side location of the piezosensor is more sensitive to changes in the Unmanned Aerial Vehicle propulsion system, which was studied with the Principal Component Analysis method applied for four main recurrence quantifications. The research presented proves the possibility of using nonlinear recurrence analysis for propulsion system diagnostics and helps to determine the optimal sensor location for more effective health monitoring of multicopter motor.

Automatic Library Book Picker

Automatic Library Book Picker is an ambitious project that aims at digitizing and automating libraries by incorporating the power of robotics, automation, and IoT technologies. This project also aims to promote a new age of technology to innovate the age-old invention of libraries. A NodeMCU serves as the core control unit for this automated library book picker, utilizing its built-in WiFi connectivity and Arduino compatibility to provide smooth control and communication. It uses pulse width modulated (PWM) signals to send information to other components. The four wheels are controlled by L298N motor drivers, which allow the robot to move in the library. Furthermore, the system incorporates a 60 RPM side-shaft DC motor to enable arm lifting operations, and a servo motor governs the functioning of a robotic gripper mechanism necessary for book manipulation. Thus, by converging these components, technologies, and advanced control algorithms, the automatic library book picker performs tasks such as retrieving books from the shelves with minimal human effort, providing security to the books in the library by reducing human contact, and also improving the user experience. Key Words: NodeMCU, L298N motor driver, Servo motor, Battery, DC Motor, Side Shaft DC Motor, PWM signals.

Design and implementation of pulse width modulation gate control signals for two-level three-phase inverters

The switching control circuit in a DC to AC inverter is the critical part that is applied to control the power transistors insulated-gate bipolar transistor (IGBTs) and metal-oxide semiconductor field-effect transistor (MOSFETs). This paper proposes a high-performance and low-cost pulse width modulation (PWM) control signal with a 120º phase shift circuit for a two-level three-phase inverter. Typically, a PWM signal with a 120º phase shift for three-phase inverters is generated with the help of analogue components with more complicated designs and power losses or by using a microcontroller with necessary programming or coding. The proposed solution is to design a 120° three-phase shift circuit based on D flip-flops and the 555-timer to generate the clock signal for the flip-flop input in addition to the dead-time control circuit. The proposed circuit is controlled by one square wave signal as an input signal to generate six output PWM control signals at 50 Hz to operate six MOSFETs in the three-phase inverter. Simulation results in power simulation software PSIM and PROTEUS simulation tools are used to verify the proposed circuit. Hardware implementation of the proposed circuit and three-phase inverter is carried out to validate the performance of the proposed design.

Maximum power point tracking and space vector modulation control of quasi-z-source inverter for grid-connected photovoltaic systems

The quasi-Z-source inverter (qZSI) become one of the most promising power electronic converters for photovoltaic (PV) applications, due to its capability to perform a buck-boost conversion of the input voltage in a single stage. The control strategy based maximum power point tracking (MPPT) and proportional integral (PI) controller are well known in grid-connected with traditional configuration but not in qZSI. This paper presents a control strategy for qZSI grid-connected based on the MPPT algorithm and the linear control by PI controllers. This is complemented by the capability to efficiently transfer the harvested power to the grid, ensuring a unity power factor. The proposed control strategy effectively separates the control mechanisms for the direct current (DC) and alternating current (AC) sides by utilizing the two control variables, the shoot-through duty ratio and the modulation index. An adapted space vector modulation technique is then utilized to generate the switching pulse width modulation (PWM) signals, using these two control variables as inputs. The proposed approach was tested and validated under MATLAB/Simulink and PLECS software.

A Novel Modularization Method for Voltage Equalization of Ultracapacitor Bank Using Coupled Inductor

The voltage equalization of ultracapacitors (UCs) in a UC bank using coupled inductors is superior due to their advantages of simple control, fast energy transfer capabilities, etc. However, as the number of UCs connected in series or parallel in a UC bank increases, the number of windings on a single core required for balancing also increases. This causes severe mismatches between the inductance of the multiple winding in a single core, making the implementation more complex. Therefore, a novel modularization method is proposed in this paper for a matrix-connected UC bank. The proposed method achieves cell balancing, module balancing, and demagnetization with less number of components. Moreover, the proposed method uses a single pair of complementary pulse width modulation (PWM) signals with a 50% duty ratio for all switches. The energy is transferred from the higher voltage cell to the lower voltage cell simultaneously through the coupled inductors, which increases the balancing speed. The balancing performance of the proposed modularization is validated experimentally.

Design, Simulation, Building, and Testing of a Microcontroller-Based Automatic Drowsiness Detection, Vehicle Braking, and Alert System

Aims: The premier practical aspect of this research drive is to propose, build, simulate, and evaluate an Arduino-built automatic vehicle driver drowsiness detection and alert system.
 Study Design: The pivotal role of a reliable braking system in vehicular safety cannot be overstated, particularly considering the escalating frequency of traffic accidents, notably prevalent in Indonesia where human factors take center stage as the primary accident catalyst. An insightful poll underscores physical fatigue or drowsiness while driving as the foremost concern. Acknowledging the nuanced disparities between conventional air systems and electric systems, this research strategically directs its attention toward crafting a new system characteristic that mirrors the efficiency of the existing systems.
 Place and Period of Study: The research action engaged by the authors in a bunch of two students under the command of a professor as a part of one of his course capstone projects for the Bachelor of Science in Electrical and Electronic Engineering degree at the American International University Bangladesh (AIUB), Dhaka, Bangladesh. The authors performed their investigative tasks at AIUB from June 2023 to January 2024.
 Methodology: Recognizing the imperative to fortify vehicular safety, the integration of artificial intelligence emerges as a vital solution to assist drivers in ensuring the safety of individuals both within and outside the vehicle. This focused study, tailored specifically for Electric Vehicles (EVs), centers on the innovative application of object and distance identification methodologies to provide a comprehensive braking action indicator. Leveraging a minicomputer and a sophisticated neural network approach, images captured by a stereo camera undergo meticulous machine learning processes. This facilitates the precise categorization and measurement of distances between objects, with subsequent priority decisions determining the optimal degree of braking action. Employing an intelligent methodology, specifically fuzzy logic, the study demonstrates a successful outcome by constructing a curve while concurrently enhancing the dynamics of the pre-existing system. Moreover, a finely tuned Pulse Width Modulation (PWM) signal for braking, lasting 10 milliseconds, is intricately devised based on the study's discerning results.
 Results: The system is simulated in Proteus and tested in real time to check its functionality. The outcomes of the test showed that the system can produce the appropriate signals based on the detection of any kind of driver’s drowsiness and can stop the car.
 Conclusion: This comprehensive approach ensures the seamless replacement of components while concurrently elevating the overall performance of the braking system

An analog PWM pixel circuit with shaping function for low grayscale display of Micro-LEDs

This paper presents a new analog pulse width modulation (PWM) micro light-emitting diode (LED) pixel circuit with a shaping function. The rising/falling time of PWM signal generated by the proposed pixel circuit can be greatly reduced to improve the low grayscale display quality of micro-LED. Metal oxide thin film transistors with the top-gate (TG) coplanar structure are used to realize the proposed pixel circuit on the glass substrate. It is shown that the pulse width of micro-LED current can be linearly modulated by the data voltage. Furthermore, the measured rising time and falling time of the PWM signal are 15.6 μs and 25.5 μs, respectively, which are much smaller than that of the PWM signal in the conventional analog PWM pixel circuits.

Spectrum analysis of digital UPWM signals generated from random modulating signals

This work studies the spectrum of discrete-time Uniform-sampling pulse width modulation (UPWM) signals originating from stochastic input signals. It demonstrates that for ergodic input sequences of independent and identically distributed random variables, the Discrete Fourier Transform (DFT) of the UPWM signals can be directly estimated from the input signal’s statistics. Consequently, it is shown that if the input signal can be modeled as such a random sequence, only statistical information of the sequence is required for the accurate estimation of the DFT of the UPWM signal. This is achieved here by proving that the DFT estimators obtained by observation of the input sequence within a time window are consistent estimators of the DFT coefficients of the underlying random process. Moreover, for signals whose generalized probability density functions can be expressed as functions of a small number of parameters, the DFT coefficients can be estimated or even calculated via closed-form expressions with linear complexity. Examples are given for input signals derived from symmetric and asymmetric distributions. The results are validated by comparison with evaluations of the UPWM signal’s DFT via the Fast Fourier Transform (FFT). The proposed method provides a mathematical framework for the analysis and design of UPWM systems whose inputs have known statistical properties.

Fuel cell stack design and modelling with a double-stage boost converter coupled to a single-phase inverter

Abstract A comprehensive proton-exchange membrane fuel cell stack model was developed and integrated with a two-stage DC/DC boost converter. It was directly coupled to a single-phase (two levels—four pulses) inverter without a transformer. The pulse-width modulation signal was used to independently regulate every converter phase. The converter was modelled using a MATLAB®/Simulink® environment and an appropriate voltage control method. The analysis features of the suggested circuit were created and, through established experiments, the simulation results were verified. A single-phase (two levels—four pulses) inverter control circuit was tested and it produced a pure sinusoidal waveform with voltage control. It matches the voltage of the network in terms of amplitude and frequency. A sinusoidal pulse-width modulation approach was performed using a single-phase (two levels—four pulses) pulse-width modulation inverter. The results demonstrated an enhancement in the standard of the output wave and tuned the dead time with a reduction of 63 µs compared with 180 µs in conventional techniques.

Design of a Shape-Memory-Alloy-Based Carangiform Robotic Fishtail with Improved Forward Thrust.

Shape memory alloys (SMAs) have become the most common choice for the development of mini- and micro-type soft bio-inspired robots due to their high power-to-weight ratio, ability to be installed and operated in limited space, silent and vibration-free operation, biocompatibility, and corrosion resistance properties. Moreover, SMA spring-type actuators are used for developing different continuum robots, exhibiting high degrees of freedom and flexibility. Spring- or any elastic-material-based antagonistic or biasing force is mostly preferred among all other biasing techniques to generate periodic oscillation of SMA actuator-based robotic body parts. In this model-based study, SMA-based spring-type actuators were used to develop a carangiform-type robotic fishtail. Fin size optimization for the maximization of forward thrust was performed for the developed system by varying different parameters, such as caudal fin size, current through actuators, pulse-width modulation signal (PWM), and operating depth. A caudal fin with a mixed fin pattern between the Lunate and Fork "Lunafork" and a fin area of approximately 5000 mm2 was found to be the most effective for the developed system. The maximum forward thrust developed by this fin was recorded as 40 gmf at an operation depth of 12.5 cm in a body of still water.

Optimisation of Torque Ripples in Permanent Magnet Synchronous Motor using Hysteresis Current Controller

This paper’s primary goal is to investigate and analyze how a particular PWM technique enhances the performance of PMSM drives. The objective of the analysis is to reduce torque ripples, which are fluctuations or variations in the motor’s torque output. Reducing these torque ripples involves combining the Hysteresis Control and Space Vector Pulse Width Modulation (SVPWM) techniques. Hysteresis Control is a method that compares the actual value of a parameter (in this case, torque) with a reference value and takes appropriate control actions based on the comparison. SVPWM, on the other hand, is a sophisticated technique used for generating pulse width modulation signals that can control the motor precisely and efficiently. The research findings suggest that combining the Hysteresis Control technique with SVPWM in the PMSM motor drive makes the system more effective and efficient. This combination likely reduces torque ripples, leading to a smoother motor operation. Using both techniques together probably enhances the precision and stability of the motor control system.

Implementation of modified trapezoidal commutation scheme for speed control of 1 kW BLDC motor

The commutation process in brushless DC (BLDC) motors is done electrically and depends on the rotor position feedback. The Six-Step method is the most commonly used method in BLDC control, as it is easy to implement. However, this method has a high root mean square (RMS) current. On the other hand, a perfect sinusoidal commutation method is very complicated. Therefore, this research proposes a simple modified scheme of trapezoidal commutation circuits that can produce sinusoidal BLDC output voltage. This circuit can still responsively control the speed of the BLDC motor. This scheme uses 2 Arduinos. Pulse width modulation (PWM) signal from Arduino2 is then combined with hall signals from Arduino1, resulting in six outputs which are modified electrical commutation signals. This commutation signal is used as a MOSFET controller in a 3-phase inverter to produce a sinusoidal waveform. The average efficiency obtained when implementing the commutation is 75 % at low and high speeds.

Genetic algorithm-enhanced linear quadratic control for balancing bicopter system with non-zero set point

Bicopter is an unmanned aerial vehicle (UAV) with the advantage of saving energy consumption. However, the unique two rotors design presents a challenge in designing a controller that achieves good stability, fast settling time, and the ability to overcome oscillations simultaneously. This article proposes a new control method for bicopter that uses a genetic algorithm optimization approach in the linear quadratic (LQ-GA) control method. The GA is used to search for the best weighting matrix parameters, Q and R, in the Linear Quadratic (LQ) control scheme. The proposed control method was tested on a balancing bicopter test platform with an input in the form of difference in pulse width modulation (PWM) signals for both rotors and an output in the form of roll angle. The control system was evaluated based on the stability of the transient response and the generated control signal. The results of the tests showed that the proposed LQ-GA control method has better stability, faster settling time, and smaller overshoot than the existing PI and standard LQ control methods. Therefore, the proposed LQ-GA control method is the most suitable for use in a balancing bicopter system with a non-zero setpoint.

Heat dissipation design of the mine-used inverter output filtering device

During long-distance transmission, pulse width modulation (PWM) signals are subject to voltage reflection. This results in spike voltages and high du/dt values at the motor end. Suppression is carried out by utilizing a series reactor at the output of the inverter. And the filtering parameters are optimally designed. Then, the EMF characteristics of the output reactor are analyzed and power losses are calculated. On this basis, an integrated heat dissipation scheme is proposed to design the output reactor for forced cooling. It is verified by ANSYS/Icepak simulation, which shows that the filter has good heat dissipation performance.

Low cost power monitoring system with electric bill calculation

A power monitoring system with electric bill calculation has been developed to measure voltage, current, power, kilowatt-hours, and prices per hour of electrical appliances and to help users to reduce the monthly bill. The prototype uses a voltage and current sensor, ESP32 Node MCU, STM32 microcontroller and a pulse width modulation (PWM) signal to control a rectifier circuit that converts alternating current (AC) to direct current (DC) that available in the market and the development took about 6 months. The prototype successfully collected electricity data and provided the energy needed for monitoring system. The prototype had a percentage accuracy of 92.22% between the calculation bill compare to IoT prototype measurement. The final prototype is a portable device that can accurately measure and record the relevant data and provide real-time monitoring and data visualization with the usage of the electricity to a certain load.

Low threshold DC–AC power converter with optimized standby power consumption

The quest for universal energy access continues to be a major concern globally. Renewable energy technologies such as solar PV are viable options to meet this energy poverty with DC–AC power converters playing a major role in solar PV systems. Current designs of these converters suffer from high standby energy consumption and high input threshold voltage. This paper presents the design and implementation of a single-phase DC–AC power converter with low threshold input voltage and optimized standby power consumption. A multivibrator, pulse width modulation signal generator, MOSFETs, and a multiple secondary winding center tap transformer were used in the system design. The results show an optimized power converter having a low input threshold voltage of 10.5V and power consumption of 9.49W.

Passivity-Based Control of Three-Phase PWM AC-DC Converters with Close to Unity Power Factor and RL Load

In the present work, a strategy is proposed to control the pulse width modulation signals of the power devices of high switching of a three-phase alternating current to direct current converter as well as the current of a load type RL guaranteeing that the power factor of the supply be the unity, which is achieved by taking advantage of the properties that the complete mathematical model has in the two-phase synchronous frame of reference. Likewise, a formal stability analysis of the complete closed-loop system is presented, thereby demonstrating that the proposed scheme guarantees global asymptotic stability with all bounded internal signals.