Implementation Of Pulse Width Modulation Research Articles

The Impact of Modulation Techniques on Brushless DC Motor Drive

ABSTRACTThree‐phase brushless DC (BLDC) motors are cost‐effective and are increasingly used in various speed control applications. The phase voltage, DC‐bus utilization, current ripple, and torque ripple are major performance parameters for a BLDC motor drive. Different pulse width modulation (PWM) methods will diversely influence these parameters. This paper presents the phase voltage, current ripple, and DC‐bus utilization analysis of BLDC motor drive for four PWM techniques and provides a comparative analysis. The current ripple of the BLDC drive is evaluated with low and high switching frequency operations. Phase voltage and DC‐bus utilization of a BLDC motor are evaluated using analytical methods and validated experimentally. The investigation provided in this work are significant for PWM selection and implementation for low and high switching frequency operations. Both low‐ and high‐frequency operations are performed by supplying the BLDC drive from a silicon carbide (SiC) based inverter. These PWM techniques are also compared, considering high and low‐speed applications. Experimental results of SiC inverter‐fed BLDC motor drive are provided to substantiate the proposed work.

Simulation and FPGA based Implementation of PI and Fuzzy Controllers for Cascaded Asymmetric Multilevel Inverter

The main objective of this work is to improve the performance of Multilevel Inverter by using the novel LS-PD- PWM and controlling technique instead of the existing approach. The proposed work focus on closed loop controller such as existing PI and Fuzzy Logic Controller for resistive load with Multilevel Inverter. The proposed Asymmetric fifteen level Inverter offers less THD and high frequency than the Asymmetric nine level inverter. Asymmetric multilevel inverter is used to reduce the switching losses and THD. In this work is the generation and implementation of Pulse Width Modulation (PWM) techniques using Field Programmable Gate Array (FPGA) for Multilevel Inverter. PWM can be generated via Microprocessors, Microcontroller, FPGA and DSP Processors. Higher density Programmable Logic Devices (PLD) such as FPGAs can be used to amalgamate large amounts of logic into a single Integrated. Pulse width modulation (PWM) is generally used in power converter control. To generate LS-PD- PWM by using FPGA, this occupies less memory capacity and accurate than conventional one. An efficient PWM generation technique is performed using FPGA for lower frequency applications. Simulation and synthesis is done by ModelSim6.3c and Xilinx10.1. Further, the Implementation is carried out by FPGA Spartan3 Xc3s50. Key Word: PWM, FPGA, PLD (Programmable Logic Devices), LS-PD-PWM

A new floor function single‐carrier‐based modulated model predictive current control technique for single‐phase PUC5 inverter topology

SummaryIn this paper, a new floor function (F2) single‐carrier (SC)‐based modulated model predictive current control technique (M2PC2T) has been proposed by considering the conventional single‐phase five‐level packed U‐cell (PUC5) inverter topology. Generally, to regulate the output current, the finite control set‐based MPC technique without a modulator inherently operates with variable switching frequency, and it is unsuitable for industrial applications. To alleviate this, authors have implemented M2PC2T, which provides constant switching frequency of operation. In this technique, generally, the predictive algorithm has been integrated with any modulation stage. However, while the implementation of pulse width modulation (PWM) techniques, most authors have used conventional PWM techniques which further increases the control complexity as the level number increases. In this manuscript, a simple and generalized F2‐SC‐PWM technique has been proposed and integrated with the predictive algorithm. This PWM technique implementation process is very simple as compared with all conventional PWM techniques since even if the level number increases, the number of modulating and carrier signals is always only one. Finally, the complete closed‐loop control technique is called a generalized F2‐SC‐M2PC2T which is suitable for all stiff direct current (dc) sources and switched capacitor‐type multilevel inverter (MLI) topologies. The proposed control technique (PCT) has been experimentally verified with different transient and steady‐state case studies by considering resistive‐inductive load.

A new single modulating and single carrier‐based predictive current control technique for single‐phase quadruple boost multilevel inverter topology

SummaryA new floor function single carrier‐based modulated model predictive current control (F2‐SCM2PC2) technique has been proposed in this paper by considering traditional single‐phase quadruple boost switched capacitor‐based multilevel inverter (QB‐SCMLI) topology. Conventionally, the implementation process of single modulating and single carrier‐based pulse width modulation (PWM) techniques are very much complex and finite control set‐based model predictive control (FCS‐MPC) technique inherently operates with variable switching frequency (VSF) operation, which is not suitable for industrial applications. To alleviate the aforementioned issues, a new generalized closed‐loop F2‐SCM2PC2 technique has been proposed. It consists of a simple PWM implementation process and can easily be integrated with a predictive algorithm, thereby providing a constant switching frequency (CSF) of operation. The particular single modulating and single carrier‐based PWM technique with floor function is also suitable for low and high switching frequency (LSF‐HSF) operations. The validation of floor function‐based PWM technique in open‐loop and closed‐loop F2‐SCM2PC2 techniques has been effectively verified through experimentation on QB‐SCMLI topology with consideration of resistive–inductive load.

Pulse width modulation control for stochastic Lagrange systems

The pulse width modulation (PWM) control for Lagrange systems driven by servo motors in stochastic environment is researched in this paper. Principles of PWM for stochastic nonlinear systems are proved, a continuous control bounded in probability of stochastic Lagrange system is designed, and the stochastic closed-loop nonlinear programming is modeled in the same form as that in the deterministic case. Sure boundedness of the control is required as a hard constraint, and the stochastic quadratic programming problem is presented for which an analytic solution is constructed and the expression of the optimal duty ratio is obtained. Finally, the main procedures of design and implementation of the stochastic PWM are summarized, and the effectiveness of the proposed scheme is demonstrated by a simulation of articulated manipulator.

BLDC Motor Drives with A Programmable Simplified C-Block to Generate Accurate Six-Step PWM Based on STM32 Microcontroller

This paper presents a digital implementation of a brushless direct current motor (BLDCM) drive with a six-step pulse width modulation (PWM) using a programmable simplified C-block based on the STM32 microcontroller. The implementation is conducted through the PSIM simulation platform, which is commonly used for power electronics and motor control. This approach combines the benefits of using a programmable simplified C-block for precise and flexible programming with the PWM concepts of the STM32 microcontroller. The PWM method used on the BLDCM drive is the unipolar upper PWM technique (H~PWM_L~ON). The performance of the PWM implementation is analyzed in detail, including the accuracy of the PWM generation using a Fast Fourier Transform (FFT), the gating of the IGBTs in the three-phase inverter, and the effect of the duty cycle on the BLDCM's speed, phase voltage, and phase current.

Per-Phase Analysis, Efficient Implementation and Performance Evaluation of a 24-Sector Discontinuous PWM for Split-Phase Induction Motor Drives

Space vector-based 24-sector pulse width modulation (PWM) techniques for split-phase induction motor (SPIM) drive offer better performance than the 12-sector PWM methods; however, these methods are complex to implement. This paper analyses a space vector based 24-sector discontinuous PWM from a per-phase perspective. Analysis of three-phase average pole voltages, pertaining to this method, shows that each phase is clamped for a 60 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> interval in each half cycle, which is divided into three sub-intervals of 15 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> , 30 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> and 15 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^\circ$</tex-math></inline-formula> , respectively. The common-mode voltage is shown to be related to the fundamental voltage of one of the phases in each sector and to that of different phases in different sectors. This analysis leads to an understanding of the offset voltages to be added to the two sets of three-phase sinusoidal modulating signals for generating the equivalent modulating signals for the two inverters driving the SPIM. Further analysis of the switching sequences suggests appropriate carrier waves for the modulating signals to be compared against. The computationally efficient implementation of the 24-sector discontinuous PWM (DPWM-1), thus developed, is validated on a 6-kW laboratory prototype SPIM drive. Stator flux ripple-based analysis is used to evaluate stator current distortion and rms torque ripple of different PWM techniques. Simulated instantaneous torque ripple and torque harmonic spectra of the different techniques are compared. The proposed method offers lower THD at high speeds and lower switching loss at high power factors than the 24-sector continuous space vector PWM with significantly low computational effort.

Design and implement of pulse width modulation with low-cost hardware in the loop

&lt;p&gt;The paper presents a low-cost hardware in the loop based on Arduino. Sinusoidal Pulse Width Modulation (SPWM) designing, analyzing, and implementation is experimented as hardware in the loop. Sinusoidal Pulse Width Modulation implementation via MATLAB\Simulation demonstrates in this work. In this paper, Arduino Mega2560 platform, microcontroller, introduce as hardware. A comparative study of the both techniques is presented. Arduino interfaces with PC Target MATLAB environment. Three phases Voltage Source Inverter directs by the generated pulses that loads with three phases RLC. The obtaining output current and voltage waveform of RLC load of Hardware-in-the-Loop validates to the MATLAB\simulation output waveform. The compering shows the output waveforms are primarily having the same pattern. Arduino consider as the lost cost as microcontroller which could be used in real application.&lt;/p&gt;

Аналіз енергетичних процесів у семирівневому автономному інверторі напруги при різних алгоритмах модуляції

The most commonly used in autonomous voltage inverter (AVI) is pulse-width modulation (PWM) and single modulation. The advantage of PWM prior to single modulation is the ability to control the amplitude of the first harmonic of the output voltage and, accordingly, the current required both for scalar and vector control of an asynchronous electric drive.Multilevel autonomous voltage inverters (MAVI) are finding increasing application in industry, namely: in wind and solar power engineering, high-voltage substations, in industrial and traction electric drives. In comparison with the classical two-level inverters, MAVI have several advantages: providing greater output power MAVI, the reduced value of the emission of higher harmonics in the load and the supply network, reduction of switching losses in semiconductor switches, which directly increases the efficiency, increased sinusoidal output voltage and current.Currently, there are several topologies of multilevel AVI, among which the most common are MAVI with fixing diodes, MAVI with convertible capacitors, MAVI with cascade half-bridge. Due to the fact that the MAVI with fixing diodes found the greatest use among the listed topologies, this article is dedicated to this type.The article examines the realizable quality parameters of the output voltage and output current in a seven-level AVI with fixing diodes during the implementation of various modulation algorithms. Methods for the implementation of PWM are considered. In Matlab / Simulink / SymPowerSystems, a seven-level AVI model has been developed with considered control systems. The results of simulation in the form of energy indicators, namely the harmonic distortion of the output current and voltage, are obtained.Results of studies of a multi-bridge active voltage-source rectifier in the interleaving mode are presented. Based on the energy balance equation were obtained relation that determine the adjusting characteristic of the output voltage in the rectification and recovery modes. Were developed Matlab models of active multi-bridge rectifiers with different number of parallel bridges and different PWM frequencies. It is established that interleaving in the active rectifier allows to significantly reduce the switching frequency of the input current. At the same time, it’s significantly reduces power losses in power switches and increases the efficiency of the active rectifier. Interleaving provides compensation of the higher harmonics of the input current. It is established that the coefficient of harmonic distortions of the output current in the mode of spatial - vector modulation is 3,71 %, and has a better index, in comparison with other modes of PWM. At the same time, lower power losses in AVI have a mode of inverted sinusoidal PWM and is 3849 W. As a result, with an increase in the number of AVI level, IGBT-transistors will also decrease losses.

Center pulse width modulation implementation based on memristor

This paper introduces two new versions for memristor-based center pulse-width modulator (PWM) circuits. The proposed circuits use only one comparator which reduces the circuit complexity and power dissipation compared to a former work. The first design is based on two memristors and two resistors while the second design is based on four memristors. Theoretical analysis is provided, and the numerical solution is handled on MATLAB. Simulation is carried out on Cadence software, and the results follow the theoretical analysis. The experiment is implemented using commercial off-the-shelf components and, the results match both theoretical analysis and simulation results.

Single-Phase to Three-Phase Converters With Two Parallel Single-Phase Rectifiers and Reduced Switch Count

This paper presents two single-phase to three-phase conversion systems for a three-phase load application. The load is connected to a single-phase grid through an ac–dc–ac single-phase to three-phase converter. The single-phase rectifier is composed of two parallel single-phase half-bridge rectifiers. The first proposed topology is composed of a full-bridge three-phase inverter, i.e., three-leg inverter, while the other topology is composed of a two-leg inverter. Suitable modeling, including the circulation current, and control strategy are presented. A pulsewidth modulation (PWM) technique using a single or double carriers PWM implementation is presented. Proposed topologies permit to improve the harmonic distortion. In addition, the P5L converter can reduce the converter power losses. Finally, simulation and experimental results are presented for validation purposes.

Bidirectional Speed Control of DC Motor Based on Pulse Width Modulation using Microcontroller

This paper presents a design, simulation and implementation of Pulse Width Modulation (PWM) speed control system of DC motor using microcontroller (MCU). The PIC16F877A microcontroller is programmed to generate two periodic PWM signals from its Capture/Compare/PWM (CCP) modules. These output PWM signals from MCU with various duty cycle are used to controlling the speed and direction of DC motor through L293D driver chip which is used as an interface between MCU and DC motor. The PIC MCU has been programmed using flowcode software package and the complete PWM control system model has been simulated using proteus design suite software package. A hardware setup has been practically implemented for the proposed control system in order to check the simulation results and which were acceptable and satisfactory.

Enhanced Phase-Shifted PWM Carrier Disposition for Interleaved Voltage-Source Inverters

This letter presents a novel implementation of pulse width modulation that improves the quality of the line-to-line output voltages in interleaved multiphase voltage-source inverters (VSIs). In multiphase VSIs with n interleaved parallel-connected legs, the best single-phase output voltage is achieved when the carriers are evenly phase shifted. However, switching among nonadjacent levels can be observed at regular intervals in the line-to-line voltages, causing bad harmonic performance. With the proposed method, switching in the line-to-line voltages happens exclusively between adjacent levels. The modulator utilizes two sets of n evenly phase-shifted carriers that are dynamically allocated. Because of its generality, the proposed implementation is valid for any number of phases and any number of legs in parallel. A MATLAB/Simulink model has been set up for simulation purposes. Selected experimental results obtained from a three-phase VSI made up with two and three legs in parallel per phase are reported, confirming the enhancement attained with the proposed implementation.

Pulse width modulation schemes enabling single DC power source driven dual two‐level voltage source inverter with single voltage source inverter switching

Three-level voltage space phasor can be obtained using a dual two-level voltage source inverter (VSI). Two zero sequence voltage elimination pulse width modulation (PWM) switching variants are proposed in this paper for complete elimination of zero sequence voltage (ZSV) in the dual-VSI scheme. Both the PWM variants are designed in such a way that only one inverter is switched at any instant of time; to ensure that switching power losses in the dual-VSI is limited to one inverter only at any instant of time. Analytical expressions for the dwell times of the dual-VSI are developed and presented that successfully forces the ZSV in the dual-VSI to zero; at all instants of time. As a result, both the PWMs facilitate the dual-VSI to be driven from a single DC power source only. The implementation of the proposed PWM algorithms is greatly simplified and involves just the use of instantaneous magnitudes of the reference space vector. The implementation of PWMs totally avoids the time consuming task of sector identification and do not use look up tables. The PWMs proposed in this paper are first analysed, simulated using MATLAB/SIMULINK and then verified experimentally to validate the proposed PWMs.

Multiplierless Implementation of an Aliasing-Free Digital Pulsewidth Modulator

Digital pulsewidth modulators are used to transform nonconstant amplitude signals into pulsed signals, such that the information lying in the signal amplitude is encoded in the widths of pulses. Because of the inherent aliasing distortion in digital pulsewidth-modulated signals, additional signal processing steps are required to make pulsewidth modulation (PWM) suitable for applications like digital audio amplification or burst-mode radio-frequency transmitters. These processing steps, however, entail an undesirable increase in computational effort. This brief presents a multiplierless implementation of a digital aliasing-free pulsewidth modulator using lookup tables, adders, and arithmetic shifts only. Mathematical equations of asymmetric double-edge PWM are given, as well as a modified aliasing-free version of this PWM technique that directly integrates the distortion-avoiding signal processing steps into the pulsewidth modulator. Based on these equations, a multiplierless implementation of the aliasing-free PWM (AF-PWM) is developed. Simulation results obtained with a Simulink fixed-point model show that the proposed modulator implementation provides a feasible solution for realizing AF-PWM with low computational effort.

Effects of Current Modulation Conditions on the Chromaticity of Phosphor Converted (PC) White LEDs

For two well-known modulation methods, stepwise current modulation (SCM) and pulse width modulation (PWM), the effects of driving current modulation conditions on chromaticity were experimentally investigated in a white LED lighting system. For the experimental implementation of both SCM and PWM, a white LED lighting was fabricated using phosphor converted (PC) white light emitting diodes (LEDs) and a driving circuit module was developed. By using them, the variations of illuminance, color coordinates, and spectrum were evaluated under various forward current conditions. Through the analysis in color coordinates, yellow shift in SCM and blue shift in PWM were observed on chromaticity diagrams with increasing average driving current. In addition, in order to analyze color deviation quantitatively, color distance before and after current increase, and the correlated color temperature (CCT) were calculated. As a result, for the white LED lighting in both modulation conditions, the maximum difference in the calculated CCT was obtained close to 1000 K. It means that careful consideration is required to be taken in the design of illumination systems to avoid serious problems such industrial accidents.

Unified Pulse‐Width Modulation Scheme for Improved Digital‐Peak‐Voltage Control of Switching DC‐DC Converters

SUMMARYContrast to conventional dependent double‐edge (DDE) pulse‐width modulation (PWM), independent double‐edge (IDE) PWM is investigated and applied to the control of switching dc‐dc converters, with improved digital‐peak‐voltage (IDPV) controlled buck converter in this paper. IDE modulation unifies all the PWM schemes reported up to now and is thus called as unified PWM. It is revealed that conventional trailing‐edge, leading‐edge, trailing‐triangle, and leading‐triangle modulations are special cases of IDE modulation. The control laws of IDPV controlled buck converter with IDE modulation are investigated and compared with those of IDPV with DDE modulation. Their stabilities and robustness are analyzed subsequently. Digital implementation of the unified PWM is also carried out. Steady‐state and transient performances of IDPV controlled buck converters with IDE modulation and DDE modulation are compared and verified by experimental results. It is concluded that steady‐state and transient performances of IDPV with IDE are better than those of IDPV with DDE modulation. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Space Vector PWM Technique for a Three-to-Five-Phase Matrix Converter

Variable-speed multiphase (more than three phases) drive systems are seen as serious contenders to the existing three-phase drives due to their distinct advantages. Supply to the multiphase drives is invariably given from a voltage source inverter. However, this paper proposes an alternative solution for supplying multiphase drive system using a direct ac-ac converter called a matrix converter. This paper proposes the pulsewidth modulation (PWM) algorithm for the matrix converter topology with three-phase grid input and five-phase variable-voltage and variable-frequency output. The PWM control technique developed and presented in this paper is based on space vector approach. This paper presents the complete space vector model of the three-to-five-phase matrix converter topology. The space vector model yield 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> total switching combinations which reduce to 243 states considering the imposed constraints, out of which 240 are active and 3 are zero vectors. However, for space vector PWM (SVPWM) implementation, only 90 active and 3 zero vectors can be used. The SVPWM algorithm is presented in this paper. The viability of the proposed solution is proved using analytical, simulation, and experimental approaches.

Optimum crossing-point estimation of a sampled analog signal with a periodic carrier

The problem of estimating the crossing points of a continuous-time random process, represented by a sequence of uniformly spaced noisy samples, with a periodic analog carrier signal is of crucial importance in the implementation of pulse-width modulation (PWM) and other event-triggered sampling systems. In this paper, we formally approach this problem from a statistical signal processing perspective under a Bayesian framework. We derive the maximum a posteriori (MAP) estimator of the crossing point from a finite sequence of noisy observations, along with a close approximation based on minimum mean squared error (MMSE) considerations. We also study the Bayesian Cramér–Rao bound (CRB) on attainable mean square estimation error. Finally, simulations of a PWM scenario demonstrate that both the MAP and MMSE estimators approach the CRB and outperform several benchmark estimators. The MMSE is a particularly attractive solution as it offers a computationally efficient approximation to the MAP estimator.

Parabolic PWM for Current Control of Voltage-Source Converters (VSCs)

A novel parabolic carrier pulsewidth modulation (PWM) method is proposed in this paper for direct current control in a voltage-source converter (VSC). This method employs a pair of parabolic PWM carriers (a positive one and a negative one) to determine the switching states of the two switches in a converter phase leg while limiting the current tracking error within a nonlinear hysteresis band. Similar to the hysteresis PWM method, the proposed parabolic PWM can regulate both dc current and ac current with excellent and accurate dynamic response. Furthermore, as a carrier-based PWM method, the proposed parabolic PWM can maintain a constant switching frequency by the automatic peak current error adjustment through the PWM process. In this paper, the basic operation principle of the proposed PWM method is discussed, and its implementation scheme is presented. Simulation and experimental results based on a single-phase VSC with bipolar PWM implementation are provided.