Pulse Width Modulation Output Research Articles

A Common-Mode Voltage Elimination Scheme by Reference Voltage Decomposition for Back-to-Back Two-Level Converters

Common-mode voltage (CMV) can greatly reduce the reliability and performance of back-to-back two-level converter-fed motor drive systems. To address this issue, a novel CMV elimination scheme based on reference voltage decomposition is proposed in this article. Firstly, the reference voltage of each phase is decomposed into two virtual reference voltages, resulting in six virtual reference voltages that are inter-related for back-to-back two-level converters. Then, by comparing each virtual reference voltage with a triangle carrier based on the two-level pulse width modulation (PWM), the final PWM voltage of each phase can be obtained from the differences of the corresponding two virtual PWM outputs. With the proposed method, both the amplitude and RMS value of CMV can be eliminated theoretically with satisfactory output waveform qualities. Simulations and experimental results are presented to verify the proposed method.

Service life estimation of electric vehicle lithium-ion battery pack using arrhenius mathematical model

Durability is a desired characteristic for all battery packs in Electric Vehicles. In this study, the service life of the EV battery pack under real-world operating conditions is projected using an Arrhenius mathematical simulation model. The model comprises a 39.2 kWh EV Lithium-Ion battery pack integrated with a three-phase inverter to convert the battery pack’s Direct Current output to Alternating Current. In addition, the Alternating Current output is coupled to a 100 kW permanent magnet synchronous motor, which is regarded as the load. A field-oriented controller provides pulse width-modulated output signals that are supplied back to the inverter to generate the correct driving current. Variable conditions of charge rate (C-rate: 1.25C − 4C), discharge rate (C-rate: 0.5C − 4C), temperature (25°C–60°C), and depth of discharge (30%–90%) are evaluated to determine the battery pack’s service life. Under a 4C charge rate/0.5C discharge rate and 50% depth of discharge, the modeling results indicate the battery pack has a service life of approximately 6,000 h at low temperatures (25°C) and roughly 3,000 h at high temperatures (60°C). The model has been validated by comparing the results with experimental data from the literature.

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.

Laser-Based Command Injection Attacks on Voice-Controlled Microphone Arrays

Voice-controlled (VC) systems, such as mobile phones and smart speakers, enable users to operate smart devices through voice commands. Previous works (e.g., LightCommands) show that attackers can trigger VC systems to respond to various audio commands by injecting light signals. However, LightCommands only discusses attacks on devices with a single microphone, while new devices typically use microphone arrays with sensor fusion technology for better capturing sound from different distances. By replicating LightCommands’s experiments on the new devices, we find that simply extending the light scope (just as they do) to overlap multiple microphone apertures is inadequate to wake up the device with sensor fusion. Adapting LightCommands’s approach to microphone arrays is challenging due to their requirement for multiple sound amplifiers, and each amplifier requires an independent power driver with unique settings. The number of additional devices increases with the microphone aperture count, significantly increasing the complexity of implementing and deploying the attack equipment. With a growing number of devices adopting sensor fusion to distinguish the sound location, it is essential to propose new approaches to adapting the light injection attacks to these new devices. To address these problems, we propose a lightweight microphone array laser injection solution called LCMA (Laser Commands for Microphone Array), which can use a single laser controller to manipulate multiple laser points and simultaneously target all the apertures of a microphone array and input light waves at different frequencies. Our key design is to propose a new PWM (Pulse Width Modulation) based control signal algorithm that can be implemented on a single MCU and directly control multiple lasers via different PWM output channels. Moreover, LCMA can be remotely configured via BLE (Bluetooth Low Energy). These features allow our solution to be deployed on a drone to covertly attack the targets hidden inside the building. Using LCMA, we successfully attack 29 devices. The experiment results show that LCMA is robust on the newest devices such as the iPhone 15, and the control panel of the Tesla Model Y.

Cascaded Inverters Increasing the Number of Levels and Effective Switching Frequency in Output Using Coupled Inductors

In this paper, a new coupled-inductor based modular multilevel cascaded inverter using a new phase-shift control is presented. The proposed inverter can generate a high output ac voltage using standard low voltage rating devices. The number of levels in the output pulse width modulation (PWM) voltage and the effective switching frequency of the output filter are increased using coupled inductors and phase-shift control. The switching signals of the cascaded units in the proposed inverter are phase-shifted by 360°/4n, where n is the number of cascaded units. The proposed phase-shift control results in (4n+1) levels in the output PWM voltage of the proposed inverter and increases the effective switching frequency of the output filter by 4n times of the actual switching frequency fsw. As a result, the output waveforms can be generated with better quality and less distortion. In addition, the output filter can be decreased dramatically in size. Besides, fewer coupled inductors are used to reduce the footprints, the number of inductors, and magnetic volume. Moreover, the proposed inverter is exceptionally reliable due to no short-circuit risk in the circuit.

Performance Analysis of Three Phase Induction Motor With Variable Frequency Drives Using Pulse Generator Pwm and Svpwm

Three-phase induction motor is an alternating current motor that is most widely used in industry or offices. In principle, the induction motor is operated at a constant speed, if the induction motor is given a load that is not balanced with its constant speed, the speed of the induction motor will change. For this reason, one of the common methods used to adjust the rotational speed of an induction motor as desired is to use a Variable Frequency Drive (VFD). The VFD can be controlled by pulse generator PWM (pulse width modulation) and SVPWM (space-vector pulse width modulation) which are part of the value of the frequency and modulation index. In this final project, what is investigated and compared for more optimal results is the PWM and SVPWM output values with the variables of Rotor Speed, Slip, Fslip, Stator Current, and THD (Total Harmonic Distortion). In this thesis, a comparison of simulation with MATLAB between PWM and SVPWM is carried out using design and experimental methods. The final result obtained is for Rotor Speed, SVPWM control is more optimal with an average percentage of 2.2%. For more optimal SVPWM control slip reaches 1.53%. for Fslip control SVPWM is more optimal reaching 0.76%, SVPWM control produces a smaller current consumption at a frequency of 50 - 40 Hz. for THD Current, PWM control is more optimal with a percentage of 1.07%

DEVELOPING A MOBILE ROBOT WITH VOICE COMMANDS

The paper deals with the development of a transport robot control system with voice commands and simulation of their movement in Microsoft Robotics Developer Studio (MRDS) software product. The advantages of MRDS over other programmes are discussed. The programming language used was VPL, a visual programming environment for creating and debugging applications. It was designed multi-level control of the robot. At the top level of control, human voice commands are recognised, setting the direction of movement of the robot and its motion functions. At the lower level, the wheel speed is controlled by a microcontroller, which generates pulse width modulation output signals.

Comparative Analysis of Solar Charge Controller Performance Between MPPT and PWM on Solar Panels

Solar power plants require other supporting equipment besides solar panels, including SCC (Solar ChargerController) for solar panel charger media to batteries. While the battery itself as a store of electrical energy generatedby solar panels. Therefore, other supporting equipment is very important in the application of solar power generationsystems.In the charger system or battery charging on solar panels, an SCC solar charger controller is needed as the chargermedia. In the solar charger controller there are two types between MPPT (Maximum Power Point Tracker) and PWM(Pulse Width Modulation). This study aims to analyze the performance comparison between SCC which is good forsolar panels in battery charging. Apart from the comparison tool, the simulation tool used in this study is which oneis superior between MPPT and PWM. The way of comparison is to compare the current and voltage results obtainedfrom the SCC input and output between MPPT and PWM to find out which one is superior.The results of the comparison with simulation produce current input from MPPT between 10, 15, 20, 25 A while PWMinput current is between 10, 15, 20, 15A. The results of the MPPT current output are between 12, 18, 21, 25A, whilethe PWM output current is between 8, 18, 21, 25A. For the MPPT input voltage results are between 29, 25, 36, 41V,while the PWM is between 26, 29, 36, 41V, while the output MPPT voltage is between 14, 14, 15, 15V, while the PWMis in the range of 14, 14, 15, 15V.

Modeling and Analysis of Voltage Harmonic for Three-Level Neutral-Point-Clamped H-Bridge Inverter Considering Dead-Time

The advantages of three-level neutral-point-clamped (NPC) H-bridge inverters, such as simple topological structure, low device voltage stress, high equivalent switching frequency, and highly expansible capacity, have made them the preferred choice for inverters matching with medium voltage high-capacity multi-phase open-end winding vessel propulsion motors. To quantitatively evaluate the propulsion motors’ harmonics, electromagnetic vibration, and noise caused by pulse-width modulation (PWM) and device dead-time, it is necessary to research the mathematical modeling of pulse-width modulated output voltage harmonics in consideration of dead-time. In this paper, the principle of the phase-disposition PWM method of the 3L-NPC H-bridge inverters was firstly introduced. Then, the analytical models of output voltage harmonics with and without considering the effect of dead-time were established based on the double Fourier series approach and the harmonic distribution of the dead-time effect was accurately characterized. On the basis of the above, the experimental platform was established to verify the proposed analytical model. Simulation and experimental results are consistent with the theoretical analysis in low and high-frequency output voltage harmonics, which proves the correctness and the feasibility of the analytical modeling method researched by this paper. This will provide a theoretical basis for subsequent studies, which include the quantitative analysis and the suppression of output harmonics of the H-bridge inverter considering dead-time.

Low-Cost MATLAB-Simulink Compatible Data Acquisition Card Hardware and Software Design for Control and Test Applications

This paper presents a general-purpose data acquisition system is designed for control and test applications. In this data acquisition system, the connections of the input-output ports and peripherals are performed by employing the STM32L4 microcontroller with ARM-Cortex M4 architecture. The microcontroller communicates with the MATLAB-Simulink, transmits given commands to peripheral units, and receives data from the environment. The system has four digital input-output, two analog inputs, two analog outputs, four pulse width modulation outputs, an L298 driver, and encoder inputs. The connections of the peripherals with the microcontroller are transferred to the printed circuit board in the Altium Designer program to perform real-world applications and test. Universal Serial Bus (USB) is used to maintain communication between Simulink library and controller. This communication process provides not only the control of input-output, sensors and driver ports but also opportunity of transfer the process of sampled data. The library created in the MATLAB-Simulink environment interprets and observes the system’s data and controls the peripherals. This library contains blocks to control the overall system and each input-output. Proposed system is intended to be low-cost, accurate, reliable, high resolution, and compatible with various environments that may communicate over the USB port.

A Chopper Class-D Amplifier for PSRR Improvement Over the Entire Audio Band

The power supply rejection ratio (PSRR) of conventional differential closed-loop Class-D amplifiers is limited by the feedback and input resistor mismatch and finite common-mode rejection ratio (CMRR) of the operational transconductance amplifier (OTA) in the first integrator. This article presents a 14.4-V Class-D amplifier employing chopping to tackle the mismatch, thereby improving the PSRR. However, chopping-induced intermodulation (IM) within a pulsewidth modulation (PWM)-based Class-D amplifier can severely degrade PSRR and linearity. Techniques to mitigate such IM are proposed and analyzed. To chop the 14.4-V PWM output signal, a high-voltage (HV) chopper employing double-diffused MOS (DMOS) transistors is developed. Its timing is carefully aligned with that of the low-voltage (LV) choppers to avoid further linearity degradation. The prototype, fabricated in a 180-nm BCD process, achieves a PSRR of >110 dB at low frequencies, which remains above 79 dB up to 20 kHz. It achieves a total harmonic distortion (THD) of −109.1 dB and can deliver a maximum of 14 W into an 8- <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega $ </tex-math></inline-formula> load with 93% efficiency while occupying a silicon area of 5 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .

Coupled Inductors for High-Frequency Drives With Parallel-Connected Inverter Legs

In this article, coupled inductors with cross-coupled windings are described and designed for voltage source converters with parallel-connected inverter legs in each phase. The nature of the cross-coupled windings produces a very low effective series output inductance, related to the intralimb leakage inductance rather than the higher interlimb leakage. The effective inductance between the parallel inverter output terminals can be made high to reduce circulating currents and is related to inductor magnetizing inductance. These two features make the use of parallel inverters attractive for generating multilevel high-frequency fundamental pulsewidth modulation output voltages with a very low fundamental voltage drop across the coupled inductors. Sample magnetic designs are presented for a three-phase system using three inverter legs connected in parallel in each phase. The effective output inductance of the cross-coupled winding arrangement is compared with that of the coupled windings on separate limbs without cross-coupling and is shown to be 97% smaller. The performance of the two inductor winding arrangements is demonstrated with simulation and experimental results of an 11 kW (300 Vdc, 208 Vac/30 A) laboratory prototype operating with fundamental frequencies in the kilohertz range up to 5 kHz.

Influence of Embedded Microprocessor Wireless Communication in the Ankle Joint Proprioception Training on the Prevention of Football Sports Injuries

This study synthesizes the relevant publications on the therapy of horizontal joint destabilization of the functional ankle and investigates the effect of anterior motion ankle drills on the inability to cause ankle injuries in soccer teams. We chose university soccer teams as the study population and divided them into five men’s and five women’s squads and five control groups. Embedded microcontrollers are also called microcontrollers. Generally, we focus on a specific type of microprocessor center, integrating ROM/EPROM, RAM, Bus Logic, Timer/Counter, Watchdog, I/O, Serial Port, Pulse Width Modulation Output, A/D, D/A, and more. Functions and Devices. Representative embedded microcontrollers include PSIXA, 8051, MCS-251, MCS96/196/296, and C166/167. With the continuous improvement of the processor’s computing power and chip integration, the differences between embedded microprocessors and embedded microprocessors have further increased. Blurred. The test subjects experienced force testing and the trial subjects involved in ankle native sensory drilling. The experimental results show that the average direction has a statistically significant effect on the front, back, left, and right running ability, which increases significantly after 0.017, 0.032, and 0.043 P, respectively, providing a more scientific basis for preventing football injuries.

The Design and Experimentation of EVPIVS-PID Harvesters’ Header Height Control System Based on Sensor Ground Profiling Monitoring

In this paper, an adaptive header height control system is designed. Through the influence of the natural frequency, ωn, and damping ratio, ζ, on the system’s dynamic index, the optimal hydraulic cylinder parameters are determined comprehensively. The ground profiling monitoring mechanism and the header height feedback mechanism based on the angle sensor are designed. An integrated electromagnetic proportional valve was installed to replace the original header-controlled, electronically-controlled reversing valve, and a PWM (pulse width modulation) control-simulated counterweight test was performed. The limitation of traditional PID facing the integral saturation state is analysed, and a new EVPIVS-PID algorithm is proposed and simulated. Through the analysis of multiple groups of sample data in the field test, the accuracy of the control system in the header height control and output PWM value is demonstrated. The effectiveness of the EVPIVS-PID control algorithm to change the corresponding PID parameters based on the monitoring operation speed is analysed and demonstrated. Experiments show that the adaptive control system of header height based on ground profiling has a stable control effect. The height error of cutting stubble is not more than 2 cm, which can meet the requirements of a 5–11 km/h harvesting speed in plain areas.

Application in Virtual System Modelling (VSM) of Sensored Pm BLDC Motor Drive Using Two Technologies of Processors PIC16F877Aand Arduino Uno R3

This paper presents the simulation of a 3-phase Permanent Magnet Brushless DC (PM BLDC) motor drive. For the studied drive system in this paper, pulse width modulation (PWM) control has been implemented for a 60-degree six-step trapezoidal PM BLDC motor drive. The used processor is Arduino and PIC16F877A, which is a common, flash-able, and low-cost microcontroller unit (MCU) with functions to perform commutation sequence, rotating direction control, speed control and reading Hall sensor signals, and calculating RPM and duty cycle of the PWM outputs signals depending on variable speed. The controlling technique uses sensored type in order to make this design suitable for low-speed and high-speed applications plus control simplicity. In this paper, The application of Proteus Virtual System Modelling (VSM) software as a real-time simulation tool is introduced to model the performance of a 3-phase Permanent Magnet Brushless DC motor drive before hardware implementation. Expected results can be monitored and analyzed throughout the virtual simulation of all components. The usage of Proteus VSM enables shorter product development time, thus reducing development costs for industrial applications.

Prototype of automatic conveyor system using programmable logic controller for educational purpose

The study of conveyor control and programming using PLC (Programmable Logic Controller) has been taught in many universities, especially in the field of Electrical Engineering. Unfortunately, the material obtained by students is only in the form of theory without direct application to the conveyor system in the industry because it is constrained by the company policy. Therefore, it is necessary to build a prototype of automatic conveyor system using PLC for educational purpose. This prototype is owned by the university so that students can directly implement the results of the PLC program design that they have learned in class. The prototype of the automatic conveyor system can increase students’ interest and understanding of the industrial automation process so that they will be better prepared when they have implemented it directly to the industry. This research discusses the design and manufacture of a prototype of automatic conveyor system using PLC. The main controlling device used is the FX3U Mitsubishi PLC which is equipped with analogue inputs, analogue outputs, and high-speed counter output as PWM (Pulse Width Modulation) output. The conveyor used is a mini conveyor with a DC motor drive. Conveyor speed control is done by adjusting the rotational speed of the DC motor using direct PWM setting from PLC. To complete the automation system, infrared sensor was added as the input to detect the dummy load. Thus, full automation system of conveyor for educational purpose was done and it showed satisfying results.

Design and Implementation of an LED Automatic Lighting System for Plant Factories

This paper proposed a light-emitting diode (LED) automatic lighting system for plant factories. This system can achieve the simultaneous effects of automatic dimming and seven-segment mixing; the light intensity and color can therefore be adjusted according to the properties of the plants to increase crop harvest. The operation method comprises detection of the light source through a photosensitive diode CdS, and sending the analog value obtained from the light intensity to the single chip dsPIC30F4011 for analog-to-digital conversion. This single chip stores the digital value in the internal pulse width modulation (PWM) register and outputs it to the dimming circuit to achieve the effect of automatic dimming. In addition, the operator can also connect to the system using smartphone Bluetooth and an ATmega328 single chip and manually select the color of the light source through the human-machine interface. The ATmega328 chip receives the operating signal and transfers it to the dsPIC30F4011, which automatically changes the PWM output channel to achieve seven-segment light mixing.

A Proof of Concept Study for the Design, Manufacturing, and Control of a Mobile Overground Gait-Training System

In this study, a mobile overground gait-training system (OGTS) was designed, and a prototype was manufactured to determine the feasibility and control stability of the designed system. Approval was received from the Institutional Review Board of Fu Jen Catholic University for conducting experimental testing on healthy individuals with the designed mobile OGTS. The designed system comprises a mobile electric walking aid (EWA), a body weight support system (BWSS), and an exoskeleton gait orthosis (EGO). The system can perform multiple functions for physical overground gait training. The mobile EWA and EGO can be operated separately from the mobile OGTS. An interval type-2 fuzzy sliding controller (IT2FSC) was designed to compensate for disturbances and uncertainties because the mobile OGTS has a coupling issue and potential subjects have different weights and body shapes. The mobile OGTS has one IT2FSC to provide a pulse-width modulation output to regulate two linear actuators for the BWSS, and it adopts four IT2FSCs to produce voltage outputs to control the gait trajectory of the EGO. Three experiments demonstrated that the mobile OGTS provides a stable control force to assist the user in overground gait training as well as assist-as-needed body weight support for gait training.

Development of a simple line-follower robot with constant acceleration motion

A simple line-follower robot is an automated guided vehicle that senses the black line on a white surface using infrared (IR) sensors and then sends the signal to the Arduino Nano microcontroller. It drives two simple DC motors attached with two wheels used to move the robot’s direction that is left, right, and forward according to the sensor’s output, and it can control the speed of DC motors from the L298N driver circuit. This research aims to develop a simple line-follower robot with constant acceleration motion as an educational tool. The design process would allow the robot to detect white and black surfaces, travel along a 3 m straight line with a constant acceleration, and permit acceleration with a smartphone sensor by the Phyphox application. The robot is equipped with the acceleration sensor of a smartphone that can collect acceleration data. The data are then graphed and analyzed using the Phyphox application in real-time. The robot is designed to help students change acceleration by adjusting the motor’s output pulse width modulation (PWM) signal from 0 to 255. The signal was set at 230, a value that can cause the robot to move with constant acceleration. The robot’s average acceleration is 0.65 m/s2. This project can help students to illustrate the acceleration concept in the form of a graph together with robot motion.

A Three-Phase Digital Current Controller Using Error-Free Feedback Acquisition With Half Delay

In this article, we introduce an improved multi-sampling-based alternate current (ac) controller that can be applied to ac machine drives or grid-connected inverters. Unlike the classical multi-sampling controller, whose performance is restricted by the transport delays in the feedback acquisition chain, the improved internal model control-based controller can provide a high closed-loop bandwidth by shortening the averaging range and inserting a cascaded differential multiplier. The corresponding modified controller structure for embedding active resistance feedback could improve the disturbance rejection ability while maintaining unchanged closed-loop performance for tracking reference. Besides the common perspectives for current controller design, discussions about robustness to parameter variations, implementation issue concerning sampling noise immunity affected by the pulse-width modulation output method, the effect of execution time, and application with high fundamental frequency are also presented. Finally, the comprehensive experimental results are obtained from a platform with a three-phase inverter, digital controller, and a surface-mounted permanent magnet synchronous motor. The results verify that the proposed controller achieves a high closed-loop bandwidth of up to 20% of the sampling frequency without overshoots and oscillations.