Pulse Width Modulation Method Research Articles

Performance Characteristics of a Newly Developed Asymmetric Seven-Level Inverter Utilizing Various Hybrid Pulse Width Modulation Strategies

This study unveils a notable breakthrough in inverter technology, holding promise for substantial improvements in voltage quality and the attenuation of harmonic distortions within power systems. This study concentrates on the design and implementation of a novel Seven-Level Asymmetric Inverter (NSLAI) by incorporating various hybrid Pulse Width Modulation (PWM) techniques. The primary goal is to improve the output voltage magnitude while decreasing the Total harmonics compared to conventional PWM methods. The investigation introduces a novel Seven-Level Asymmetric Inverter (NSLAI) with innovative Hybrid Pulse Width Modulation (PWM) strategy. The purpose of this study is to investigate the distinct features of a recently developed asymmetric seven-level inverter, with a focus on exploring its characteristics through the implementation of diverse hybrid pulse width modulation strategies. Hybrid PWM methodology intricately centers on enhancing voltage quality and achieving better harmonious spectral characteristics. The gate signal producing approach for this suggested PWM technology incorporates a hybrid PWM methodology that combines trapezoidal and sinusoidal waveforms, as well as a standard triangular carrier signal enabling NSLAI.  The hybrid version of PWM practices is deliberately used to generate switching signals for the NSLAI. An intensive evaluation of numerous indicators of effectiveness across multiple modulation indexes leads in the demonstrating of quantitative findings that compare the unique Hybrid PWM practice with established PWM tactics. Notably, the hybrid reference Carrier Overlapping strategy has emerged as a leading approach surpassing conventional pulse width modulation techniques. It achieves a significantly higher fundamental Root Mean Square voltage output and remarkably lower percentage of Total Harmonic Distortion values compared to all within the hybrid reference Variable Frequency strategy. The principal analytical tool used in the modeling investigation is MATLAB-SIMULINK. This study marks a watershed moment in the development of inverters, claiming significant improvements in battery power quality and distortion caused by harmonics avoidance across power systems, as evidenced by extensive simulation and prototype-based discoveries.

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.

An Improvised Modulation and Control Approach for Dual Active Bridge DC–DC Converter System

Aimed at the control and modulation of dual active bridge bi-directional dc (DAB-BIDC) converter, an unconventional approach is applied to explore its effect in symmetrical wave-based isolated dc-dc converters. The existing control schemes of DAB-BIDC converter with unified or optimal phase shift (UPS/OPS) modulation have the constraints like complex control schemes, light load efficiency, current stress, and reactive power. Since a 50 Hz, grid-connected conventional converter system uses the sinusoidal pulse width modulation method to minimize the requirement for passive filters. Similarly, this work investigates the same analogy for the high-frequency (HF) symmetrical wave converters to get effective modulation and control scheme for the DAB-BIDC converter. Furthermore, the proposed sinusoidal pulse width-phase shift (SPW-PS) modulation scheme has been implemented by the optimally derived control parameters using Lagrange's Multiplier Method (LMM) to minimize the reactive power flow and current stress reduction at the HF link. Therefore, the DAB-BIDC converter with the proposed modulation and control approach can be used for EV charging and solid-state transformers applications. Finally, the proposed work is validated using MATLAB simulation and experimental setup having turn ratio 36/12 V, fundamental frequency 5-kHz, and switching frequency 100-kHz for the experimental validation using OPAL-RT.

Design and implementation of a reduced switch seventeen-level multilevel inverter for grid integration of battery storage system

Multilevel inverters (MLI) have a variety of applications in battery storage system, renewable energy integration, electric vehicle (EV), drives for industry and in various flexible AC transmission system (FACTS). Applications of MLI in battery storage system have greatly increased over the past few decades. Conventional MLIs used for grid integration of battery energy storage is having large number of components and it requires transformer for grid integration. The large number of components and transformer increases the cost, size, weight and losses of the MLI, thus reduces the efficiency of the system. Keeping this in view, the goal of the proposed work is to design a novel reduced switch seventeen-level MLI which is having a lower number of components and do not require transformer for grid integration. This modular nature of proposed MLI is used to increase power handling capacity without introducing additional converters. For this, first proposed reduced switch seventeen-level MLI has been compared with other existing seventeen level topologies which in order to show the effectiveness of proposed topology. After analysis its effectiveness, the proposed MLI has been designed and then closed loop d-q current controller for grid connected mode is analyzed. The different curves are plotted to justify the stability of proposed inverter. The control of output voltage is also included using modified sine pulse width modulation (SPWM) method. The proposed MLI has been implemented in MATLAB/Simulink and validated using real time hardware-in-loop (HIL) emulator.

Five-phase space vector carrier-based PWM for third harmonic injection

Five-phase AC drives allow a third harmonic voltage to be fed into the stator winding – in addition to the fundamental voltage – to generate a third harmonic magnetic air gap field. This allows the generation of an additional small constant torque. Furthermore, the undesirable saturation harmonics that occur with saturated iron can be compensated. The desired third harmonic voltage is commonly generated via time-consuming space vector PWM algorithms, which are not well-suited for real-time application, or via look-up tables, which require an increased storage capacity. In our case, the desired third harmonic voltage is generated in the five-phase voltages by adding a non-sinusoidal zero-sequence voltage with five times the fundamental frequency to the fundamental voltage reference signals in carrier-based pulse width modulation (PWM) with a constant switching frequency. This is equivalent to a space vector PWM method (SVPWM) and avoids a significantly high calculation effort. The PWM algorithm programmed in MATLAB in real time allows the fast generation of a third harmonic voltage per phase with freely definable amplitude and phase shift without requiring a lot of storage capacity.

Capacitor sizing of three‐level neutral point clamped voltage source inverter for electric vehicles: Effects of modulation and motor characteristics

AbstractA three‐level neutral point clamped (3L‐NPC) voltage source inverter (VSI) topology can be advantageous in electric vehicles with a high DC‐link voltage and a high switching frequency. A bulky DC‐link capacitor is not an option; thus, the DC‐link capacitor's sizing considering the traction system characteristics is an important design step. This paper investigates how the DC‐link capacitor size of a 3L‐NPC VSI gets affected by the combination of the interdependent characteristics of an electric drive, such as its power factor, modulation index, current, and fundamental frequency, with the effects of the modulation methods. Five pulse width modulation (PWM) methods, of which three of them have an active neutral point potential control, are compared in terms of their neutral point potential (NPP) oscillations. Then, the size of the DC‐link capacitor is determined for each PWM method so that the NPP ripple is kept under desired limits at all operating conditions. It is shown that both the modulation technique and the electric machine characteristics influence the capacitor size. For example, electric machine design modifications can introduce more than a 30% reduction in capacitor size. Finally, DC‐link and NPP oscillations with different PWM methods are experimentally validated in a scaled‐down 3L‐NPC inverter.

Optimal Hybrid Pulse Width Modulation for Three-Phase Inverters in Electric Propulsion Ships

Global interest in environmentally friendly ships has surged as a result of greenhouse gas reduction policies and the demand for carbon neutrality. Despite growing demand for electric propulsion systems, there is a lack of research and development on crucial components. Efficiency and stability are primarily influenced by the performance of inverters, which are essential for driving propulsion motors. Existing inverter control techniques can be of two types: continuous-PWM (pulse width modulation) methods for harmonic performance enhancement and discontinuous-PWM methods for efficiency improvement by reducing losses. However, there are limitations in that each PWM method exhibits substantial variations in inverter performance based on its operating conditions. To address these challenges, this study proposes the hybrid pulse-width-modulation (HPWM) method for optimal inverter operation. By analyzing the inverter’s operating conditions, the proposed HPWM method adopts various pulse-width-modulation (PWM) strategies based on a modulation index to achieve harmonic improvement and loss reduction. Our focus is on comparing and analyzing diverse PWM techniques under varying modulation indices and frequency conditions to attain the optimal operating conditions. Experimental validation of the proposed method was conducted using a 2.2 kW dynamometer. In comparison with existing PWM methods, the proposed method demonstrated superior performance.

Dual-Phase-Shifted Pulsewidth Modulation of Three-Phase Modular Multilevel Converters

The modular multilevel converter (MMC) has been a crucial component for medium/high-power energy conversion systems due to its modular structure. In the literature, the harmonic analysis of MMC with different modulation methods, including the conventional carrier phase-shifted pulse width modulation (CPS-PWM) method, have been extensively investigated. However, the influence of the carrier displacement angles between three-phase legs on the output performance of an MMC is normally ignored. This paper proposes a dual-phase-shifted PWM (DPS-PWM) for a three-phase MMC which further enhances the performance of the conventional CPS-PWM scheme through proper selection of carrier displacement angles between three phases. First, the operation principle and implementation of the proposed DPS-PWM method is described. Then a two-dimensional (2D) Fourier model is derived to analyze how the carrier displacement angles between stacks and legs affect the harmonics of output voltage and circulating current. It is found that DPS-PWM can suppress specific harmonics in the line-to-line voltage by coordinating the carriers' phase shifting between the three-phase legs without affecting phase voltage and circulating current. Finally, the effectiveness of the DPS-PWM method is verified by simulation and experimental results.

Design of a novel control hysteresis algorithm for photovoltaic systems for harmonic compensation

Solar photovoltaic (PV) system design and integration with an existing AC grid is growing very fast in recent years and used by many of them as they are pollution-free, structure is limited and maintenance free. From the factors considering, the performance of PV system depends upon the inverter output voltage tested for linear, non-linear, with harmonic, and without harmonic loads. Generated due to the nonlinear loads. Better inverter control techniques are developed to maintain grid power quality. This article discusses the analysis and comparison of pulse width modulation (PWM) converters with unique and state of the art nonlinear control schemes and various modulation approaches. The primary objective of this research is controlling an active filtering hysteresis PWM converter with no sensors. A simple structure with hysteresis current control method total harmonic distortion (THD) is lower when compared with the sinusoidal pulse width modulation (SPWM) method. The said claims are supported by employing computer simulations using MATLAB/Simulink and different control approaches, such as proportional plus integral and artificial neural network controllers.

A Power-Decoupled Three-Phase Current Source Inverter with Model Predictive Control in An Unbalanced Grid

The current source inverter (CSI) is a promising interface between the Photovoltaic (PV) panel and the three-phase AC grid. It boosts the PV panel voltage by a DC-link inductor and converts the maximum available PV power. In an unbalanced grid, double-line-frequency pulsating powers will be generated in the CSI, increasing the rating of the DC-link inductor and impeding the maximum power point tracking (MPPT) operation. To address this issue, a power decoupling (PD) circuit for a three-phase CSI is proposed in this paper. By using the DC-link inductor and active switches multiplex, the proposed PD circuit can reduce the current rating of the DC-link inductor with fewer active switches, and no detrimental power components are introduced to the utility grid. Moreover, to concurrently control multiple objectives without multiple loops, a model predictive control (MPC) method is further proposed for the PD-CSI, achieving a rapid response of PD-CSI. Besides, a space vector pulse width modulation (SVPWM) method is proposed for the PD-CSI to enhance the utilization of DC voltage, helping to reduce the voltage stress of the ripple storage capacitor. The priorities of the proposed topology and the corresponding control and modulation methods are finally verified by comparative experimental results.

Simulasi Sistem Pengendalian Motor Stepper dengan Metode Pulse Width Modulation

This paper discusses the control of a stepper motor using Pulse Width Modulation (PWM) methods. In this paper, the author presents two designs: one using a stepper motor controller with an astable multivibrator as a pulse generator and the other utilizing a microcontroller as the pulse generator. The design of the stepper motor controller with an astable multivibrator involves using the IC timer 555 to control the stepper motor speed and a latch circuit to control the direction of the stepper motor rotation. Meanwhile, the design of the stepper motor controller with a microcontroller employs the Arduino UNO R3 to control both the direction and speed of the stepper motor. Testing is conducted through a simulation of the system design using Proteus software. From the test results, it is observed that an increase in the PWM value leads to a faster rotation speed of the stepper motor, conversely, a decrease in PWM value results in a slower rotation speed of the stepper motor.

Comparative Analysis of PWM Techniques for Interleaved Full Bridge Converter in an AC Battery Application

The AC battery utilizing second-life time batteries has gained great interest currently with the advantages of both power solutions and economic benefits. In this system, the power converters play a crucial role in the stable and effective operation of the system. This paper focused on the AC/DC stage with the chosen topology being the interleaved full bridge (IFB) converter due to its flexibility and the ability to increase the power rate of the system. For the sake of high-performance operation, various pulse width modulation (PWM) methods for this converter are analyzed. First, based on the theory of the traditional PWM methods for a full bridge inverter in combination with the interleaved technique, this paper proposed three interleaved PWM methods for the IFB converter. Secondly, the proposed methods are theoretically compared in terms of the output current, common-mode voltage, and power losses. Finally, the evaluation is carried out by both the simulation and the experimental prototype, in which the results are in good agreement with the theoretical analysis.

A Simulation Analysis of Grid-Connected DSTATCOM with PWM Voltage Control and Hysteresis Current Control for Power Quality Improvement

Abstract The DTSTACOM is a power quality compensator that can be used in the distribution grid to compensate the demand of reactive power, which can be produced by different linear and non-linear loads. In this process, the control method of DSTATCOM is one of the key factors influencing the performance of DSTATCOM. This study aims to analyse the effect of two modulation schemes, Pulse Width Modulation (PWM) and Hysteresis Current Control (HCC), under several conditions. The proposed modelling approach and Synchronous Reference Frame (SRF) theory are used to verify reactive power compensation and total harmonic distortion (THD). Further, PWM and Hysteresis Current Control (HCC) with proportional-integral (PI) controller simulated in MATLAB for different cases, and percentage THD was calculated to prove the effectiveness of the proposed method for the control of reactive power and THD with grid-connected DSTATCOM. The results presented here justify that the HCC controller can be better than the PWM method to generate the PWM pulses for reduction of harmonics under various conditions of DTSTACOM to compensate the reactive power. Additionally, the simulation was performed to check the efficacy of the projected method to reduce THD by varying the current control band of HCC.

An Easy-Implemented Pulse Width Modulation Method for Vienna Rectifier with Minimized Current Distortion including Over-modulation Operation

An Easy-Implemented Pulse Width Modulation Method for Vienna Rectifier with Minimized Current Distortion including Over-modulation Operation

An Analysis and Optimization of the Battery Capacity Difference Tolerance of the Modular Multi-Level Half-Bridge Energy Storage Converter

As a power converter of battery energy storage, the multi-level converter and its battery balancing control have received much attention from scholars. This paper focuses on the modular multi-level half-bridge energy storage converter (MMH-ESC), including its topology, working principle, and pulse width modulation (PWM) methods. Under the battery balancing control strategy based on level-shifted carrier PWM (LS-PWM), formulas are derived and calculations are performed to get the charge or discharge of each submodule (SM), thereby obtaining the tolerance for capacity differences among these batteries. A range of battery capacity values that can maintain a balanced state is provided to enhance flexibility in battery configuration and utilization, avoiding the limitation of all batteries to the same capacity. Finally, a new bridge arm modulation wave allocation method is proposed. This method significantly expands the range of SM battery capacity selection and provides a high-tolerance modulation method for the converter under extreme or even fault conditions.

Power Conversion Systems with Synchronous Control and Regulation on the Base of Powerful Diode-Clamped Inverters via Pulse Width Modulation

This article provides a brief overview of the development and dissemination of the method of synchronous multi-zone pulse-width modulation (PWM) in relation to the regulation of diode-clamped inverters which are the main executive elements of the medium-power and high-power adjustable speed electric drives. It is shown that the modified schemes and algorithms of synchronous multi-zone PWM, applied for control of diode-clamped inverters, assure providing minimization of the common-mode voltage in systems, as well as continuous synchronization and symmetry of the base phase and linear voltages in drive systems on the base of diode-clamped inverters over the entire control range. There are no even harmonics and subharmonics in the spectra of the phase and line-to-line voltages of three-phase and six-phase drive systems, which helps to reduce losses in systems and increase the efficiency of their operation. As a result of a comparative analysis of the integral spectral characteristics of the main voltage waveforms of adjustable speed drives based on diode-clamped inverters, recommendations are formulated for the rational choice of schemes and algorithms of synchronous multi-zone PWM for the relevant systems and installations, depending on their operating modes.

Applications of power electronics technology: Advanced inverters

An inverter is a crucial component of renewable energy systems, converting direct current from solar panels and wind turbines into alternating current for use in homes and businesses. Inverters have a wide range of applications in power electronics technology, including electric vehicles, industrial equipment, and microgrid. Maximizing the efficiency of inverters is a hot research topic in the electronic and electrical fields. Engineers and researchers are interested in understanding the structure and parameters of inverters to optimize their performance. This article explores the basic inverter topology, presenting three circuit structures and their pulse-width modulation waveform modulation method. It also introduces a new type of inverter and explains its working state. The article concludes by examining potential future developments and research directions for inverters. As the world seeks to transition to cleaner energy sources, inverters will continue to play a vital role in making renewable energy systems more efficient and cost-effective.

Dual Random Noise Suppression Strategy for Permanent Magnet Synchronous Motor Based on Random Pulse Width Modulation and Random High-frequency Injection Method

This study proposes an innovative dual control strategy to tackle the challenge of electromagnetic noise in the sensorless low-speed operation of Permanent Magnet Synchronous Motors (PMSM). The strategy combines random Pulse Width Modulation (PWM) technology with a stochastic high-frequency injection approach. By incorporating two distinct randomized frequency switching techniques into the high-frequency injection circuit, the method integrates two-state Markov chains into both PWM technology and the random high-frequency injection method. Subsequently, a mathematical model for signal processing is developed, and extensive simulation and experimental verification are conducted. The experimental findings affirm the effectiveness of this approach in effectively mitigating electromagnetic noise while ensuring accurate location estimation within an acceptable range.

Сравнительный анализ математических описаний и методов широтно-импульсной модуляции

The article considers the mathematical description and comparison of the most common methods of pulse-width modulation (PWM) for a three-phase voltage inverter, namely vector PWM, PWM with third harmonic premodulation and classical PWM. In contrast to the classical mathematical description of PWM, a description is presented that is close to the implementation of modulation using modern microcontroller technology. The classic representation of PWM is based on comparing two signals. In this representation, the modulation pulse occurs at the moment when the modulating function is greater in value than the reference signal. When implementing PWM by a microcontroller, the pulse is placed within the period symmetrically with respect to the middle of the interval, while the pulse width is determined by the average value of the voltage modulating function. With a different mathematical description of PWM, the pulse is located differently within the modulation interval. There are presented the results of modeling and compares the mathematical descriptions of PWM methods according to the criterion of minimum dispersion of the current flowing in the load. As a result of the comparison, it was revealed that the same, differently described PWM algorithm gives different results. A comparison of vector PWM with a modified vector PWM was made. The modification consists in applying a dynamic pulse shift algorithm in such a way as to obtain a minimum of current dispersion in the load. Comparison of PWM methods was carried out at different frequencies of the reference signal; a static RL circuit was used as a load when simulating a three-phase voltage inverter. The results obtained allow us to recommend a pulse shift algorithm for implementing PWM in voltage inverters operating at relatively low PWM frequencies. Minimization of the current dispersion makes it possible to obtain improved energy and vibration-noise characteristics of the electric drive.

Compact three‐phase multilevel inverter with boosting capability for low‐power three‐phase induction motor drive

SummaryThis paper proposes a step‐up three‐phase multilevel inverter based on switched capacitor (SC) cells. The prominent features of this inverter are the reduction of the number of components (such as switches, capacitors, and sources) and the ability to boost the voltage. Also, the self‐voltage balancing of the capacitors of this inverter is one of the other features of this inverter. The level‐shifted pulse width modulation (LS‐PWM) method has been used for switching, making the output currents' total harmonic distortion (THD) low. The article has presented the experimental results of this inverter with a three‐phase induction motor with a power of 1.1 kW as a load.