Pulse Width Modulation System Research Articles

Solar Panel Power Generator with Automatic Charging using PWM System based on Microcontroller

Indonesia will become a net importer if it runs out of oil and gas reserves within the next 11 to 12 years if no alternative energy sources are developed. Therefore, there is a need to utilize alternative energy that is not dependent on oil or gas. One alternative energy is using solar light energy. This research designed a device that can convert the energy of sunlight into electrical energy and automatically store electrical energy in a battery with PWM (Pulse Width Modulation) so that it can be used as alternative energy, and help reduce the consumption of electricity from PLN. The battery used 12V 80Ah and a solar panel module 50W for energy storage and system resources. The research results show that systems can automatically charge energy using sunlight and turn the lights to 7W. Using the charging system automatically uses PWM to reduce the risk of damage to the battery because, in the charging process, battery conditions will be monitored. The maximum power generated from solar panel modules used is 35.57 W.

Automated Laboratory Kilogram-Scale Graphene Production from Coal.

The flash Joule heating (FJH) method converts many carbon feedstocks into graphene in milliseconds to seconds using an electrical pulse. This opens an opportunity for processing low or negative value resources, such as coal and plastic waste, into high value graphene. Here, a lab-scale automation FJH system that allows the synthesis of 1.1kg of turbostratic flash graphene from coal-based metallurgical coke (MC) in 1.5h is demonstrated. The process is based on the automated conversion of 5.7g of MC per batch using an electrical pulse width modulation system to conduct the bottom-up upcycle of MC into flash graphene. This study then compare this method to two other scalable graphene synthesis techniques by both a life cycle assessment and a technoeconomic assessment.

Concert Exploration of DFIG Grid-integrated MMC using Artificial Intelligence

The performance of grid-connected wind turbine systems that use a Doubly Fed Induction Generator (DFIG) is explored in this work. In the suggested configuration, two conversion stages are present. In the first step, Alternating Current (AC) voltage is changed into Direct Current (DC) voltage. At this point, the conventional two-level converter is implemented. The second stage involves the conversion of DC to AC using a five-level Modular Multilevel Converter (MMC). Voltage fluctuation is observed in the DC link. It is anticipated that the Fuzzy Logic Control (FLC) approach will be able to adjust the DC link voltage at the MMC of the second stage of conversion. For the purpose of the Pulse Width Modulation (PWM) system, the current controller is accountable for regulating the current signals and the reference signals. As a result, the PI Controller (PIC) is being evaluated for use in this function. Carrier-based Phase Disposition (PD) PWM is employed for MMC switch control. The proposed controllers’ performance is validated in Matlab/Simulink.

Development of a Highly Sensitive and Low Hysteresis Temperature Sensing System With PEDOT:PSS Containing Polymer Sensing Membrane

In our study, we have designed and developed a side-polished optical fiber (SPOF) pulsewidth modulation (PWM)-based sensing system that can detect temperatures from 21 °C (room temperature) to 70 °C. According to the proposed SPOF PWM system, the received sensing signal pulsewidth changes if the optical fiber temperature sensing element (TSE) gets heat. The pulsewidth changes due to a change in the refractive index (RI) of the heat-sensitive polymer membrane of the SPOF TSE. We applied poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) as the primary temperature-sensitive sensing material to make the heat-sensitive polymer sensing membrane of the designed TSE. To the best of our knowledge, it is the first temperature sensing system/device where the optical sensing element uses PEDOT:PSS containing polymer sensing membrane and the optical PWM technique. The sensitivity and linearity of the designed TSE were approximately 960 ns/°C and 0.997, respectively. A microcontroller ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{C}$ </tex-math></inline-formula> ) and readily available electronic component-based light detection and signal processing unit were designed to process the received sensing signal. The proposed temperature sensing system has different features: low cost, susceptibility, excellent hysteresis response, good reproducibility, highly stable performance, and others. The proposed SPOF TSE offers first response and recovery times of approximately 2.59 and 3.14 s, respectively. Finally, in our study, we compared the sensing performance of the proposed TSE with other temperature sensors in terms of the temperature measurement range, linearity, and response/recovery time. We found that the overall sensing performance of the proposed TSE is better than the other temperature sensors.

Comparative Performance Analysis of the DC-AC Converter Control System Based on Linear Robust or Nonlinear PCH Controllers and Reinforcement Learning Agent

Starting from the general topology and the main elements that connect a microgrid represented by a DC power source to the main grid, this article presents the performance of the control system of a DC-AC converter. The main elements of this topology are the voltage source inverter represented by a DC-AC converter and the network filters. The active Insulated Gate Bipolar Transistor (IGBT) or Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) elements of the DC-AC converter are controlled by robust linear or nonlinear Port Controlled Hamiltonian (PCH) controllers. The outputs of these controllers are modulation indices which are inputs to a Pulse-Width Modulation (PWM) system that provides the switching signals for the active elements of the DC-AC converter. The purpose of the DC-AC converter control system is to maintain ud and uq voltages to the prescribed reference values where there is a variation of the three-phase load, which may be of balanced/unbalanced or nonlinear type. The controllers are classic PI, robust or nonlinear PCH, and their performance is improved by the use of a properly trained Reinforcement Learning-Twin Delayed Deep Deterministic Policy Gradient (RL-TD3) agent. The performance of the DC-AC converter control systems is compared using performance indices such as steady-state error, error ripple and Total Harmonic Distortion (THD) current value. Numerical simulations are performed in Matlab/Simulink and conclude the superior performance of the nonlinear PCH controller and the improvement of the performance of each controller presented by using an RL-TD3 agent, which provides correction signals to improve the performance of the DC-AC converter control systems when it is properly trained.

CLOSED LOOP BIDIRECTIONAL BUCK-BOOST CONVERTER FOR BATTERY

Charging and discharging batteries A DC bus (with a constant voltage), a battery, a common load, and a bidirectional two-switch Buck-Boost DC-DC converter are used here.1- The control of battery charging as well discharging is based on using PI controllers 2- The other is for battery current regulation. The presented case study includes two modes of operation: 1-Charging mode: automatically activated when the DC bus is connected and the control objective i.e.: set point (of the PI closed loop) becomes the full voltage of the battery. 2-Discharging mode: automatically activated when the DC bus is NOT connected and the control objective (of the PI closed loop) becomes load voltage to maintain the constant load voltage during discharging. In control topology, a distinct control as well as pulse width modulation (PWM) system is created for each mode of operation using the voltage feedback control strategy. This method of charging and discharging can be used in a vehicle to grid and grid to a vehicle (here vehicle is considered as battery source/ DC source because of the same operation. Renewable energy can be used as a source to reduce pollution. The other mode of charging and discharging can be done with the help of solar as renewable resources to charge the battery. These are the way by which the closed loop buck-boost converter are been used for the battery operation.

An efficient and high gain switched-capacitor based multi-level inverter

A new switching-capacitor-based boosting multilevel inverter is described in this paper. A nine-level voltage waveform is produced using 10 switches, one-diode, and two-capacitors. Each fundamental cycle contains numerous occurrences of capacitor voltages being linked in parallel with the source voltage, resulting in self-balancing capacitor voltages. Proposed topology has built in polarity changing ability so no H-bridge is required. This paper describes a simple pulse-width modulation system based on logic gates that maintains power balance among the capacitors. For obtaining the higher voltage gain extended topology of proposed topology is also presented. The prototype’s experimental results are provided for verifying the working and boosting capability by four times of source voltage. A thorough comparison with contemporary topologies demonstrates the cost-effectiveness of the suggested topology, as well as the fact that it is a simpler construction that requires less space and consumption of resources.

Controlling Speed in Induction Motors with Fuzzy Logic and a PI Controller

The purpose of this paper is to illustrate the dynamical response of speed using the design of a Fuzzy Logic Controller (FLC) to regulate the motor speed, while the load changes. Induction motor power control has become popular in recent years in high-performance drive systems. It is due to its amazing qualities, such as high-performance, a high energy factor, and significant toughness. The overall performance of the controller is estimated using MATLAB or Simulink software and a common Proportional Integral (PI) management technique. This work discusses the design and construction of a voltage supply inverter-based Space Vector Pulse Width Modulation (SVPWM) system for regulating the speed of an induction motor. This observation also incorporates a fuzzy controller into the SVPWM to maintain the motor speed constant even when the load varies. FLC is used to alter the pulse width of the Pulse Width Modulation (PWM) converter, which controls the motor pace. This paper describes the application of a rule-based Mamdani type FLC to a closed loop induction motor model.

Nozzle pressure uniformity and expected droplet size of a pulse width modulation (PWM) spray technology

Pulse width modulation (PWM) is currently implemented in agricultural sprayers to deliver the expected flowrate by managing the duty cycle and maintaining the target pressure and provide the desired droplet size. However, there are still issues about the application errors caused by the pressure variations when using this system as it may result in pesticide resistance and product loss. Field tests were conducted in a 30.0 ha (ha) and 54.0 ha fields to assess the pressure uniformity and the expected droplet size of the PWM technology. These parameters were also translated to an equivalent value if a flow-based system will be used during operation.Results showed that pressure mostly remained within the acceptable range in both fields. Pressure CV were within 10.0%, indicating the system's ability to provide acceptable pressure at varying conditions. However, nozzle pressure still varies, especially at the outer boom section where frequent duty cycle variation occurs. Pressure also deviates during acceleration and deceleration, indicating the system's latency to respond rapidly on changing conditions. In a flow-based system, the pressure varies due to varying speed as dictated by field terrain, curvilinear paths, and headland maneuvers. The droplet size also deviates from the expected droplet spectra based on the nozzle manufacturer’s specification when using a PWM system. However, the PWM system can still provide the target droplet size if a nozzle selected provides the desired droplet spectra in a wide range of pressure. In a flow-based system, the droplet size was expected to vary because of the fluctuation in application pressure due to speed changes during operation.

Field assessment of a pulse width modulation\xa0(PWM) spray system applying different spray volumes: duty cycle and forward speed effects on vines spray coverage

The pulse width modulation (PWM) spray system is the most advanced technology to obtain variable rate spray application without varying the operative sprayer parameters (e.g. spray pressure, nozzle size). According to the precision agriculture principles, PWM is the prime technology that allows to spray the required amount where needed without varying the droplet size spectra which benefits both the uniformity of spray quality and the spray drift reduction. However, some concerns related to the effect of on–off solenoid valves and the alternating on/off action of adjacent nozzles on final uneven spray coverage (SC) have arisen. Further evaluations of PWM systems used for spraying 3D crops under field conditions are welcomed. A tower-shaped airblast sprayer equipped with a PWM was tested in a vineyard. Twelve configurations, combining duty cycles (DC: 30, 50, 70, 100%) and forward speeds (FS: 4, 6, 8 km h−1), were tested. Two methodologies, namely field-standardized and real field conditions, were adopted to evaluate the effect of DC and FS on (1) SC variability (CV%) along both the sprayer travel direction and the vertical spray profile using long water sensitive papers (WSP), and (2) SC uniformity (IU, index value) within the canopy at different depths and heights, respectively. Furthermore, the SC (%) and deposit density (Nst, no stains cm−2), determined using short WSP, were used to evaluate the spray application performances taking into account the spray volumes applied. Under field-controlled conditions, the pulsing of the PWM system affects both the SC variability measured along the sprayer travel direction and along the vertical spray profile. In contrast, under real field conditions, the PWM system does not affect the uniformity of SC measured within the canopy. The relationship between SC and Nst allowed identification of the ranges of 200–250 and 300–370 l ha−1 as the most suitable spray volumes to be applied for insecticide and fungicide plant protection products, respectively.

Research on Automatic Control System of MR Damper Based on Neural Network Algorithm

The use of MR dampers can achieve the absorption of harmful vibrations such as seismic waves that affect the structure of the building itself. The current control of the MR damper generally uses a pulse width modulation system to control the current input to the MR damper, thereby controlling the MR damper. But this is a semi-automatic control method, and the error is relatively large. This article introduces an MR damper control system that introduces a neural network algorithm. The system uses a half-bridge drive circuit for output current control in the circuit part and uses the Shen BP network algorithm for numerical prediction and fitting. The experimental research and tests conducted in the project show that the use of this fuzzy algorithm can make the MR damper achieve good damping effects under different conditions, and can well improve the original semi-automatic control method.

Embedded processor system for controllable period-width multichannel pulse width modulation signals

This paper proposes a sophisticated embedded processor system configured on zynq-xc7z020 field programmable gate array (FPGA) device for generating four channels pulse width modulation signals with variable duty cycles and periods using embedded design techniques. The main advantages of the technique are the high ability to perform a simultaneous control on period and pulse width of the generated signals and a high system design adaptation to choose the number of input/output channels. Controlling the the period and the pulse width is achieved by injecting a digital signal to the designed system to manipulate embedded timers’ operation. Vivado design suite is used to develop the system hard ware in the integrated development environment where the processing unit and peripherals are instantiated and interconnected. A practical aplication program in C language is prepared to make the system act according to the target. The designed system can be used to drive multi-phase D.C to D.C convertors. The system performance is verified by using vivado logic analyzer and chipscope windows. The superiority of the proposed approach over other approaches is that it resulted in a multi-inputs/multi-outputs pulse width modulation system with high controllability on the pulse width and the period that ranges from 15 nsec to 60 sec.

Field Performance Evaluation of Pulse-Width Modulation and Pressure-Controlled, Fixed-Orifice Application Systems for Sensor-Based Nitrogen Applications

HighlightsComparison of PC system and PWM system in-field performance indicated that the PWM system made sensor-based N applications more accurately than the PC system.The turndown ratio calculated from the aggregate application instances was 6.2:1.For both the PWM system and the PC system, applications were made more accurately when 28% UAN was applied rather than 32% UAN. Abstract. Sensor-based nitrogen (N) applications have shown promise for improving N use efficiency, but present significant challenges for application rate control due to highly variable and frequently changing target rates. If applications are to be made precisely, equipment systems used for sensor-based N applications must be designed to meet system demands. Pulse-width modulation (PWM) equipped systems have emerged as a technological advancement over traditional pressure-controlled (PC) systems for improving variable rate N application accuracy. Little research, however, has been done to assess the performance of PWM systems during sensor-based N applications in-field. This work analyzed as-applied data collected from in-field sensor-based N applications with pressure-controlled (PC) and PWM systems in Nebraska between 2015 and 2017 to quantify system requirements, assess system performance, and determine performance impacting operational variables. It was found that systems should be capable of 1-s rate changes of ±71.1 L ha-1 (7.6 gpa), 1-s flow rate changes of ±11.4 L min-1 (3 gpm), and turndown ratios of at least 6:1. PWM systems achieved application rates within 10% of the target rate 10% more often than PC systems, and showed less variability in application error. However, PWM systems still demonstrated significant application errors with an observed RMSE of 44.9 L ha-1 (4.8 gpa). Speed change magnitude was found to be most associated with increases in percent application error. These findings substantiate that PWM systems effectively improve sensor-based N application accuracy versus traditional PC systems. However, collaborative efforts toward greater cohesion between sensor-based application expectations and application equipment capabilities are necessary for maximizing the effectiveness of sensor-based N applications. Keywords: Precision agriculture, Rate controllers, Site-specific crop management, Sprayer, Turndown ratio.

Investigation of different MPPT techniques based on fuzzy logic controller for multilevel DC link inverter to solve the partial shading

Generally, partially shaded conditions frequently arise in large photovoltaic generation systems which in turn cause system losses. Therefore, arrival of multiple peak values is possible in the power–voltage characteristic curves of photovoltaic systems. Such kind of issues is resolved through the usage of novel control algorithms for multilevel dc link inverters. These algorithms depend on the arrangement of pulse width modulation and direct pulse width modulation system to be with MPPT performance based on fuzzy controller to control the multilevel DC link inverter. Under the partial shading conditions, the proposed algorithm is applied on single-phase seven-level inverter with isolated maximum power point tracking techniques. The maximum power recovery of photovoltaic sources is enabled by several maximum power point tracking (MPPT) techniques like modified perturb and observe (P&O), incremental conductance and voltage hold P&O. The spectral quality of the inverter output is observed through the simulation studies of MATLAB/Simulink working platform. Also, hardware results are verified with the help of ATMEGA8 microcontroller.

Using pulse width modulation with carrier frequency changing for transmission of two separate signals

Pulse width modulation (PWM) is widely used in different applications. PWM transforms the information in the amplitude of a bounded input signal into the pulse width output signal without suffering from quantization noise. The frequency of the output signal is usually constant. In this paper, the new PWM system with frequency changing (PWMFM) is described. In such PWMFM the pulse width and also the carrier frequency are changed. Therefore, two independent pieces of information can be simultaneously transmitted over one channel; hence PWM and frequency modulation (FM) are simultaneously used. But such system needs 2 demodulators, one for PWM and the second for FM. PWMFM can be used in the following applications: LED light intensity control via PWM and several LED block switching by FM PWMFM is highly useful in motor speed control applications by PWM and direction of rotation with FM. PWMFM can be used also in a class-D audio amplifier for power control, e.g. coarse by means of FM and fine by PWM. PWMFM can be used for the simultaneous transmission of two independent information between all, mutual combinations of analog and digital circuits. The analog and digital circuits for modulation and demodulation of PWMF signal are described and measuring results are presented in this work.

Fish behavior characterization with an RGB-LED intensity based on pulse width modulation (PWM) system in fixed lift net

The application of the Red-Green-Blue Light-Emitting Diode (RGB-LED) based on Pulse Width Modulation (PWM) with a microcontroller system is considered a possible measure for effectiveness in the fixed lift net. The effectiveness of a fishing lamp can be determined from how fish attract light and gather in the zone of catching lift net that can be monitored using fish behavior monitoring. This study aimed to investigate the light intensity of the RGB-LED and the distribution of fish behavior in the lift net. An experiment used four kinds of PWM intensity, 250 PWM, 95 PWM, 20 PWM, and 5 PWM. Fish behavior and distribution were monitored under there light intensity zone: center, main, and influence zone both spatial and temporal. The 250 PWM had dispersed intensity distance, whereas the 95 PWM, 20 PWM, and 5 PWM had focused more on the front. Overall, schooling fish was dominated in the main zone (1×10−6 W cm−2-3×10−7 W cm−2). The highest value light intensity was found on 95 PWM with accounted for 48.67% because the fish schooling adaptation is relatively consistent. These results suggest that fishing enterprises can improve catching performance by using light intensity 95 PWM.

Disturbance Observer Assisted Error Sensitive Predictive Control for Induction Motors in Sensor less Environment: A Vector Field Control Model

The exponentially rise within the demands of Induction Motors in several applications has revitalized academia-industries to develop more robust and efficient IM drives. Amongst the main classically available IM drives efforts are made either to regulate speed or torque. However, the problem inculcated due to parametric mismatch and resulting errors have much addressed. Though, predictive control based approaches are found potential to help current and torque control; however, ensuring optimal controllability under non-linear condition remained a tedious task. Filter based approaches to impose delay that eventually impacts overall control performance. Realizing it as motivation, during this research a highly robust Disturbance Observer Assisted Error Sensitive Predictive Control Strategy for IM control is developed. Subsequently, a completely unique Disturbance Observer-based Model Predictive Control strategy is developed that performs predictive current control and torque-control during a non-linear environment. Our proposed model exploits the concept of Prediction-Error to realize transient controllability. Exploiting the error information our proposed model identified the optimal voltage vector value to be injected to the 3-∅ inverter connected to the PI-based Space Vector Pulse Width Modulation system to perform transient controllability. Structurally, our proposed system encompasses SQIM motor, 3-∅ inverter, PI controller SVPWM, Flux-observer, Torque and Speed controllers, VSI units, etc. The MATLAB 2017a based simulation has revealed that the proposed model is able to do better current control, flux-torque control and torque-ripple suppression, which broadened its employability for varied applications demands fast-torque control during a noisy environment.

Star-shaped control-vector sets of second-order systems with PWM-type input

This paper deals with second-order continuous-time linear time-invariant systems by means of a pulse-width modulation (PWM)-type input. In general, it is difficult to analyze and design a PWM system because of its nonlinearity in terms of the duty ratio. In this paper, it is shown that the nonlinearity appearing in the discrete-time model at the sampling instants can be eliminated by varying the location of the pulse as well as the duty ratio.

Light intensity design as a fishing tool on liftnet, with pulse width modulation system based on microcontroller

Fishing can be done in various ways, including by utilizing lights as fishing tools. The lights used for fishing tools are varied, ranging from torch lights, pressure paraffin lamp, fluorescent lamps (TL, PL, SL, CFL), mercury, and various types of led. However, light transition between one colors to another often scares the fish, driving them out of catchable area shocked by the color change. One solution to address this problem is by smoothly switching the color of the lamp using Pulse Width Modulation (PWM) system on the microcontroller. The color used are the lamp with basic colors of red, green and blue. With power capacity of 50Watt/12Volt, this lamp is classified as High Power Led (HPL) lamp. The light can be free- adjusted, where each lamp can be turned on by its own light or can also be turned on in combination. It can slowly be switch on from an off position to maximum and also can be dimmed from maximum to off. Thus the intensity of the light can be controlled. The HPL and control sections were created separately. Tools and materials used are consist of push-button, microcontroller, optocoupler, mosfet and Red, Green and Blue HPL, Radio-meter (ILT5000 Research Radiometer), Voltmeter, and Amperemeter. The method used was experimental in both laboratory and field. The result of research is in the form of RGB HPL lamp which can be adjusted through control system, such as adjusment for each lamp, or light combination with smooth color transition. Thus, when this technology is applied as fishing tool in liftnet fishing, the targeted fish would still remain on catchable area.

Novel PDMS-Based Sensor System for MPWM Measurements of Picoliter Volumes in Microfluidic Devices.

In order for automatic microinjection to serve biomedical and genetic research, we have designed and manufactured a PDMS-based sensor with a circular section channel using the microwire molding technique. For the very precise control of microfluidic transport, we developed a microfluidic pulse width modulation system (MPWM) for automatic microinjections at a picoliter level. By adding a computer-aided detection and tracking of fluid-specific elements in the microfluidic circuit, the PDMS microchannel sensor became the basic element in the automatic control of the microinjection sensor. With the PDMS microinjection sensor, we precise measured microfluidic volumes under visual detection, assisted by very precise computer equipment (with precision below 1 μm) based on image processing. The calibration of the MPWM system was performed to increase the reproducibility of the results and to detect and measure microfluidic volumes. The novel PDMS-based sensor system for MPWM measurements of microfluidic volumes contributes to the advancement of intelligent control methods and techniques, which could lead to new developments in the design, control, and in applications of real-time intelligent sensor system control.