Pulse Width Modulation Control Research Articles

Using Active Filter Controlled by Imperialist Competitive Algorithm ICA for Harmonic Mitigation in Grid-Connected PV Systems

Solar energy has been gaining momentum recently, with a focus on maximizing its investment potential due to its reputation as the most sustainable and efficient energy source. This shift towards solar power could potentially reduce the reliance on oil-based fuels in the future. As a result of the integration of photovoltaic (PV) energy sources into the grid, the reliability of power distribution and maintaining its quality in these systems has become increasingly important. The presence of non-linear loads in these grids causes distortion of both voltage and current waves on the grid side, so it is necessary to implement effective reduction techniques to reduce the distortions in these waves. The research contribution is TO introduce the integration of an active filter on the dc side of grid-connected PV systems, along with a control circuit for the filter switches. The control switches were operated using a Sinusoidal Pulse Width Modulation (SPWM) control scheme, while the controller parameters were tuned using the Imperialist Competitive Algorithm (ICA). The proposed system was simulated in the MATLAB/Simulink environment with variations in solar radiation and temperature. The simulation results demonstrated a reduction in the total harmonic distortion factor (THD) for voltage and current waveforms on the grid side, which are within the permissible limits. This confirms the effectiveness of the proposed filter and the efficiency of the control strategy and algorithm for parameter adjustment.

Full state observer-based pole placement controller for pulse width modulation switched mode voltage-controlled buck Converter

Switched mode DC-DC converters play an important role in today's renewable energy systems, electric Vehicles, consumer electrical appliances, and many more. While many researchers have designed controllers for DC-DC converters, achieving low implementation cost remains a significant hurdle. This paper proposes a cost-effective observer-based pole placement controller for a PWM voltage-controlled Buck converter with clear step by step design approach. The state space averaged model of the DC-DC power converter is used to design pole placement with integrator compensator and full state observer. Pole placement is employed to improve the transient and steady state behavior of Voltage reference tracking response and full state observer is applied to extract the inductor current with the aim of removing the actual current sensor. Design specifications are set to a settling time of less than 5 msec and an overshoot of less than 5 %. While designing Observer-Controller combination, the separation principle, designing the controller and observer independently, is utilized by placing the observer poles far to the left of the controller poles for the Observer to converge faster. The designed controller and observer is verified with simulation in MATLAB/SIMULINK software and design of developed controller and observer are realized using low-cost analog electronics circuit components The results shows that the proposed system's strength in tracking the reference output voltage even in the presence of input voltage disturbance and the mean value of inductor current is well extracted having only the output voltage and MOSFET gate signal.

PMSM motor drive and their control schemes

This paper investigated different control Techniques of Permanent magnet synchronous motor (PMSM) drive with open loop, voltage/frequency (V/F) control, closed-loop Space Vector Pulse Width Modulation (SVPWM) control, and sensor-less Modified Space Vector Pulse Width Modulation (MSVPWMM) control with MATLAB/Simulink. The different applications of commercial used required different control schemes due to cost-effectiveness. In a small commercial application where not much precision is required, open-loop or V/F control is used, due to their easy calculation and implementation and becomes a low-cost product outcome. Where their high precision has required closed-loop control is being adopted. In this paper, closed-loop SVPWMM and sensor-less MSVPWM techniques are proposed. The algorithm has a very fast response and output has fewer glitches, highly efficient. Constant speed response available at desired load. The control techniques have been modeled and simulated in MATLAB simulation software. The proposed scheme provides efficient performance in steady-state and dynamic load conditions.

A new single modulating and single carrier signal based control technique for symmetrical and asymmetrical multilevel inverter topology

Abstract In literature, to generate gate pulses for any inverter topology, most of the authors are using a single modulating signal with (level-1) or (level-1)/2 carrier-based pulse width modulation (PWM) techniques and single carrier (SC) signal with (level-1)/2 modulating signal based PWM techniques. Then, while going to higher-level inverter topologies, the complexity of the PWM control approach in both cases can increase. To reduce the control complexity, few authors have reported a single modulating signal with single carrier-based PWM techniques. However, these techniques need more mathematical equations and if-else loops. This article proposes a new single-modulating and single-carrier signal-based generalized PWM control approach using floor function (FF). This technique has been verified by considering one of the single-phase conventional symmetrical and asymmetrical multilevel inverter (MLI) topologies. Generally, FF rounds the value to the nearest integer towards the negative infinity. The proposed PWM control implementation process is very simple and suitable for both high switching frequency (HSF) and low switching frequency (LSF) operations. The proposed control technique (PCT) has been experimentally verified with different steady-state and transient-state studies of results under standalone operation.

Real-time of a two-level three-phase inverter controlled by PWM and full wave techniques

Sustainability in power generation is readily available and must be able to adapt to a variety of energy needs or integrate seamlessly into alternative distribution networks. This research aims to bridge the gap between continuous energy production and efficient energy utilization by advancing the understanding and application of three-phase dual-level voltage inverters. This study focuses on two main objectives: firstly, to develop a comprehensive model and secondly, to validate the functionality of a three-phase two-level voltage inverter. The control strategy employed for this inverter involves the full-wave method and pulse-width modulation (PWM). The results obtained from the hardware implementation of these control methods show impressive levels of success, closely matching the expected performance of the three-phase inverter. This success underlines the robustness and effectiveness of both full-wave and PWM control strategies. To further underline their practical applicability, experimental validation of PWM and Full Wave control methods is demonstrated in a controlled research laboratory environment.

NOUVEAU FILTRE DE PUISSANCE ACTIVE SHUNT BASÉ SUR UN ONDULEUR NPC À NEUF NIVEAUX UTILISANT LA STRATÉGIE DE MODULATION MC-LSPWM

This paper presents a novel shunt active power filter (Shunt APF) system based on a nine-level neutral point clamped (NPC) inverter, which can reduce current harmonics under various nonlinear loads. These loads can introduce harmonic currents within the system, which causes excessive power losses and alters the voltage systems' characteristics. Today, multi-level inverters are more suitable for high-voltage applications; their advantages are low harmonic distortions, low switching losses, low electromagnetic interference, and low acoustic noise. The reference signals required to compensate harmonic currents use the synchronous detection method (SDM) with phase disposition sinusoidal pulse width modulation (PD-SPWM) control due to its low complexity and superior performance. The proposed shunt APF configuration simulation is evaluated using MATLAB-Simulink and SimPowerSystem environment with inductive and capacitive non-linear loads. The simulation results show the efficiency of the proposed shunt APF in terms of harmonic compensation and power quality improvement. The results of comparative studies with other less multi-level inverters confirm the superiority of the proposed shunt APF system.

TECHNOLOGIES FOR POWERING HIGH-PERFORMANCE OZONE GENERATORS: TRENDS AND PERSPECTIVES

Ozone generators are devices that produce ozone gas for various applications, such as water treatment, air purification, and medical sterilization. The performance of ozone generators largely depends on the technology used to power them. This article provides an overview of the latest trends and perspectives in technologies for powering high-performance ozone generators. We discuss various power sources, such as corona discharge, ultraviolet radiation, and electrolysis, and their advantages and limitations. We also review recent developments in power electronics and control systems for ozone generators, including pulse-width modulation, frequency modulation, and feedback control. Finally, we discuss future directions for research and development in ozone generator technology, such as the use of renewable energy sources and the integration of ozone generation with other technologies for sustainable water and air treatment.

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.

Load sensitive control characteristics of a novel two-dimensional pulse width modulated variable mechanism

Load sensing technology is a typical hydraulic technology that automatically meets load requirements by adjusting the pressure and flow at the pump outlet. Traditional load sensitive pump control systems rely on variable mechanisms to achieve such flow control characteristics. However, general variable mechanisms have complex structures and poor dynamic performance if frequently adjusted. Therefore, a new variable mechanism, named two-dimensional pulse width modulation rotary valve, is proposed. Different from the pulse width modulation control method of the electronic technology, the two-dimensional pulse width modulation rotary valve conducts secondary distribution of the quantitative pump output in the way of fluid pulse width modulation: the valve core rotates to generate discrete fluid, and the axial sliding of the valve core controls the duty ratio of the discrete fluid. The dynamic balancing of the axial displacement is controlled by feedback pressure to provide a fixed differential pressure for the control valve, achieving that the flow through the control valve is uniquely controlled by the valve opening of the control valve. The principle of the fluid pulse width modulation is first introduced, and then the mathematical model of the proposed variable mechanism and the corresponding system is established. Simulation analysis is implemented. Finally, the effectiveness of the load sensing system controlled by a two-dimensional pulse width modulation rotary valve is verified by the experiment.

A grey wolf optimization-based modified SPWM control scheme for a three-phase half bridge cascaded multilevel inverter

The Multilevel inverter (MLI) plays a pivotal role in Renewable Energy (RE) systems by offering a cost-effective and highly efficient solution for converting DC from Photovoltaic (PV) sources into AC at high voltages. In addition, an innovative technology holds immense significance as it not only enables the seamless integration of PV systems into the grid but also ensures optimal power generation, thereby contributing to the widespread adoption of RE and fostering a sustainable future. This paper presents a modified sinusoidal pulse width modulation (SPWM) control scheme for a three-phase half-bridge cascaded MLI-powered PV sources. The selection of the MLI configuration is motivated by its reduced number of switching components, which enhances system reliability and simplifies experimental implementation. Compared to the SPWM schemes which require (m−1) carriers that make the generation of the pulse circuit very complex, the proposed control scheme requires only three signals: a carrier signal, a triangular waveform, and a modulating signal. This approach significantly reduces the complexity of control and facilitates practical implementation. The proposed control scheme simulation is verified using MATLAB/SIMULINK Software. The grey wolf optimization (GWO) algorithm is implemented to determine the optimal switching angles of the proposed control scheme. The Total Harmonic Distortion (THD) objective is selected to be the fitness function to be minimized for improving the quality of the output waveforms. For verification, the results of the proposed GWO-based modified SPWM control scheme are compared with those obtained using both the Particle swarm Optimization (PSO) and Genetic algorithm (GA) used in the literature. Simulation results declared that the proposed control scheme improves performance, especially THD which is minimized to 6.8%. Experimental validation has been conducted by building a laboratory prototype of the proposed system. The experimental and simulation results gave acceptable and limited convergent results considering the experimental difficulties.

Stabilization for a Class of Feedforward Nonlinear Systems via Pulsewidth-Modulated Controllers

Stabilization for a Class of Feedforward Nonlinear Systems via Pulsewidth-Modulated Controllers

Study on combined optimization technology of wind-solar-storage hybrid power generation based on electricity hydrogen complementarity

The wind-solar-storage hybrid power generation system is mainly composed of wind turbines, solar cell arrays, electrolytic cells, fuel cells, battery packs, intelligent controllers, multi-functional inverters, cables, supports and auxiliary parts to supply power to the load. The system utilizes wind and solar energy for power generation without an external power supply, and an energy storage module composed of an electrolytic cell, fuel cell, and battery is used to assist the power supply. In this paper, a fuel cell model, a wind power generation model and a solar power generation model are respectively constructed, and a small experimental platform was built to validate the model. The pulse width modulation (PWM) control method, combined with the auxiliary regulation of the system by the battery, reduces the impact of the volatility of wind power generation on the electrolytic cell and fuel cell, and makes the load current more stable under different working conditions. The simulation results show that the system has good compression resistance, fast response and good stability.

Modelling and characteristics analysis of an electro-hydraulic proportional valve with a discrete pilot stage for underwater hydraulic manipulators

As the harshness of the underwater operating environment and complexity of underwater tasks gradually increase, underwater hydraulic manipulators with high reliability and precision attract more research attention. To improve the reliability and dynamic performance of the traditional electro-hydraulic proportional valve (EHPV) used in the underwater hydraulic manipulator, an improved electro-hydraulic proportional valve with a discrete pilot stage (DEHPV) is proposed. In the pilot stage, two 2-position 3-way normally open high speed switching valves (HSVs) are used, and the initial oil spring stiffness in the control chamber is large enough to maintain the dynamic performance of the DEHPV. First, the working principle and configuration of the DEHPV are both given, and the coupled electric-magnetic-mechanical-fluid model of the DEHPV is presented. Moreover, a dual-valve hybrid pulse width modulation (DVHPWM) control strategy is proposed to improve the position tracking accuracy of the DEHPV. Furthermore, a co-simulation model of the DEHPV considering the multi-field coupling law is established to study the dynamic characteristics. Extensive experiments are carried out to verify the effectiveness of the proposed structure as well as its good dynamic performance and control accuracy.

Analysis of Different PWM Techniques for Enhanced Ultrahigh Gain Z-Network Topology

In these modern times, the Z-source inverters (ZSIs) have become a revolutionary invention ever since the year 2002. The pulse-width modulation (PWM) technique used for most of the ZSIs is simple boost control PWM (SBC-PWM), and the SBC-PWM implies for a greater voltage stress on the inverter bridge and provides less boost factor. Likewise, many topologies for the basic Z-source topologies are evolved, and different PWM techniques are applied to them such as maximum boost control (MBC), maximum boost control with third harmonic injection (MBC-THI), maximum constant boost control (MCBC), and constant boost control with third harmonic injection (CBC-THI). All these mentioned PWM techniques are compared, and the converter opted in this paper is an enhanced ultrahigh gain active-switched quasi-Z-source inverter (EUHG-qZSI). The comparisons discussed in this brief are bridge stress, voltage gain, and voltage boost variation under each control strategy implementation. The theoretical and simulation evaluation for the abovementioned findings is presented in this paper, and the best PWM among them is maximum boost control (MBC).

Analysis of a self-sufficient photovoltaic system for a remote, off-grid community

Background The escalating global population, surpassing seven billion in 2012, amplifies the strain on existing resources for food, housing, and conventional energy. Addressing these challenges requires the development of economically and environmentally viable renewable energy technologies. Photovoltaic (PV) solar modules stand out for their eco-friendly operation and reliability. In off-grid communities, stand-alone PV systems, coupled with battery storage, play a pivotal role in meeting electrical energy needs. Methods This study enhances the understanding of stand-alone PV systems through modeling and simulation using MATLAB software. A multi-crystalline PV system, specifically the Kyocera KC130GT, is investigated under varying conditions, and a pulse width modulation (PWM) controller is employed for battery charging. Results The study reveals profound effects on energy production based on the I-V and P-V characteristics of the modeled system when a PWM controller is utilized. The system demonstrates successful energy generation under different conditions, accounting for temperature variations and PV battery voltage mismatches. Conclusion The simulated model serves as a versatile system capable of detecting different conditions in varying light and temperature scenarios. Effective temperature monitoring, voltage adjustment using a suitable charger controller, and the selection of optimal materials for solar modules can significantly enhance the system’s efficiency. The results emphasize the importance of careful consideration of PV system sizing corresponding to battery capacity for improved solar system efficiency. While the cost of the modeled stand-alone PV system is currently low, scalability to larger projects may incur increased costs due to the high prices of photovoltaic panels, batteries, and other components.

Discrete Switching Sequence Control for Converter Reference Tracking With Zero Steady-State Errors

This letter proposes a discrete switching sequence control (dSSC) to achieve zero steady-state error tracking for L-type converters. Considering switching characteristics of power electronics, a discrete-time model is established and dSSC is designed step-by-step. A strict mathematical proof ensures that the proposed dSSC achieves reference tracking with zero steady-state errors. Meanwhile, the theoretical discussion shows that the expected dynamics is obtained by choosing the control parameter of dSSC. Compared with classical methods such as pulse width modulation (PWM) and model predictive control (MPC), the proposed dSSC systemically analyzes and designs the dynamics and steady-state accuracy of converters, from a switching theoretical viewpoint. Simulations and experiments verify the effectiveness of the proposed dSSC.

An LLC resonant converter with wide output range fixed frequency PWM control for PEV charging applications

PurposeThis study aims to regarding the application of traditional pulse frequency modulation control full-bridge LLC resonant converters in wide output voltage fields such as on-board chargers, there are issues with wide frequency adjustment ranges and low conversion efficiency.Design/methodology/approachTo address these issues, this paper proposes a fixed-frequency pulse width modulation (PWM) control strategy for a full-bridge LLC resonant converter, which adjusts the gain by adjusting the duty cycle of the switches. In the full-bridge LLC converter, the two switches of the lower bridge arm are controlled by a fixed-frequency and fixed duty cycle, with their switching frequency equal to the resonant frequency, whereas the two switches of the upper bridge arm are controlled by a fixed-frequency PWM to adjust the output voltage. The operation modes of the converter are analyzed in detail, and a mathematical model of the converter is established. The gain characteristics of the converter under the fixed-frequency PWM control strategy are deeply analyzed, and the conditions for implementing zero-voltage switching (ZVS) soft switching in the converter are also analyzed in detail. The use of fixed-frequency PWM control simplifies the design of resonant parameters, and the fixed-frequency control is conducive to the design of magnetic components.FindingsAccording to the fixed-frequency PWM control strategy proposed in this paper, the correctness of the control strategy is verified through simulation and the development and testing of a 500-W experimental prototype. Test results show that the primary side switches of the converter achieve ZVS and the secondary side rectifier diodes achieve zero-current switching, effectively reducing the switching losses of the converter. In addition, the control strategy reduces the reactive circulating current of the converter, and the peak efficiency of the experimental prototype can reach 95.2%.Originality/valueThe feasibility of the fixed-frequency PWM control strategy was verified through experiments, which has significant implications for improving the efficiency of the converter and simplifying the design of resonant parameters and magnetic components in wide output voltage fields such as on-board chargers.

Developing a novel personal thermoelectric comfort system for improving indoor occupant’s thermal comfort

Personal comfort systems (PCSs), which target to condition only the occupied zones of indoor space, have received considerable interest due to their validity in thermal comfort improvement and building energy saving. Recently, the thermoelectric module (TEM) has been utilized in the design of PCS for its high reliability, small size and noise-free operation. However, the PCSs using the TEM generally lack the effective control strategy with occupant’s feedback, thus reducing their actual effectiveness on improving thermal comfort. In this paper, a novel personal thermoelectric comfort system (PTCS) is developed with a feedback control framework embedded into it. The PTCS is mainly composed of a thermoelectric conversion unit, a micro blower, control/drive modules and a tube network. A thermal comfort feedback control strategy is proposed for the PTCS. In this strategy, a thermal comfort feedback table is established based on offline experiments, and the tube outlet airflow velocity and temperature setpoints are obtained simultaneously through the table look-up method. Then, the neuron PID control algorithm and pulse width modulation (PWM) of voltage are adopted to adjust the tube outlet airflow velocity and temperature for tracking the obtained setpoints. Experimental results validate the effectiveness of the thermal comfort feedback control strategy. Thermal imaging results on human body demonstrate the availability of the developed PTCS. Performance comparison with other PCSs is also provided, which indicates the potential for practical applications.

Modelling and simulation of sinusoidal pulse width modulation controller for solar photovoltaic inverter to minimize the switching losses and improving the system efficiency

Modelling and simulation of sinusoidal pulse width modulation controller for solar photovoltaic inverter to minimize the switching losses and improving the system efficiency

Development of an Electric Variable Air Assist System for Apple Orchard Sprayers

Highlights Electric air assist system was developed with electric fans, pulse width modulation (PWM) controllers, a custom-designed air channel, and a battery. Adjusting PWM duty cycles from 0% to 100% achieved average exit air velocities from 0 to 11.3 m s-1. Spray applications with the system at 50% and 70% power achieved canopy pass through spray coverages from 4.1% to 19.9% and 14.2% to 24.2%, respectively. A multivariable regression model was developed to adjust air assist outputs based on tree canopy density and off-target loss. Abstract. Air assist for apple orchard spray applications is a necessity to deliver pesticides to target crops. However, conventional orchard sprayers use axial fans to provide air assists which are generally designed for tall crops. Thus, these systems have very limited capabilities to control airflows to match canopy densities. An electric air assist system (EAAS) was developed with an electric fans, pulse width modulation (PWM) controllers, a custom-design air channel, and a 400-Ah LiFePO4 battery to address such limitations. The system could ramp up its airflow to nearly 80% of its maximum in 2.5 s, while it took approximately 4 s to reach 100% airflow from no air assist. The EAAS provided airflow of 11.3 and 5.3 m s-1 at the fan outlet and 1 m away, respectively, with 100% duty cycles (DC) of PWM. It was capable of modulating its average air velocities from 0 to 11.3 ms-1 by changing DCs. Spray coverage samples of constant rate applications with different air assist levels were collected from the behind apple tree canopies throughout the 2023 growing season to characterize the potential for off-target spray drift. A multivariable regression model for controlling DCs was developed with the spray coverage data and leaf area index (LAI) to minimize the off-target drift. The EAAS was a promising approach to developing more advanced air assist spraying systems to enable the adjustment of both air and liquid flows based on canopy characteristics to maximize spray depositions on intended targets while minimizing spray drift. Keywords: Air assisted sprayer, Automation, Crop protection, Fan, Penetration, Pesticide, Pulse width modulation, Variable air assistance.