Sinusoidal Pulse Width Modulation Research Articles

Reduction of Motor Drive System Loss by 5th Harmonic Superimposition PWM Control

Herein, the loss reduction of a motor drive system is experimentally studied by means of the 5th harmonic superimposition in the reference signal of a sinusoidal PWM inverter from the perspective of nonlinear magnetic characteristics. The measured data of the motor drive system loss exhibits a reduction of 1.5% in the condition when the superimposition rate is -0.15. More specifically, the motor core, copper and inverter losses are reduced. The results confirm the feasibility and efficacy of the proposed method. According to the fundamental research of a ring test with the same electrical steel as the motor, the magnetic characteristics of the B-H curve changes in the case of the 5th harmonic superimposition, which decreases the fundamental component of the current. Accordingly, the loss is considered to be reduced due to the decline in the fundamental current component and carrier frequency components.

Hybrid Fuzzy Logic Multilevel Inverter for Cost Management in Wind Turbines

Wind energy is a valuable renewable resource, and advances in wind energy technology have made it more cost-effective. The future of wind-electric transformation will depend on improvements in power electronic devices. A bridge-less power factor corrected buck-boost conversion has been developed for the wind energy conversion system, and for each voltage level, the total harmonic distortion, current, and power factor have been computed using MATLAB/Simulink with sinusoidal pulse width modulation approach for inverter switches. The simulation findings demonstrate that the proposed Cascaded H-Bridge (CHB) with a single DC source can efficiently manage voltage, current, and power factor through fast discrete wavelet transform analysis and switch management. The CHB-Multilevel Inverter (MLI) logic employs intermediate output voltages and is connected in a series of multiple single-stage inverters. The presented method compares current and planned performances and does not require different DC supplies for grid utility, resulting in cost-effective wind turbine management.

Investigation of Single-Phase, Single Voltage Source Multilevel Inverter with Voltage Boosting Gain Based on Different Sinusoidal Pulse Width Modulation Approach

Investigation of Single-Phase, Single Voltage Source Multilevel Inverter with Voltage Boosting Gain Based on Different Sinusoidal Pulse Width Modulation Approach

Proposal of Hybrid Discontinuous PWM Technique for Five-Phase Inverters under Open-Phase Fault Operation

One of the most common issues in inverters are open-circuit faults (OPF). In this scenario, a proper fault-tolerant technique must be used to improve the motor performance. Although basic fault-tolerant modulation techniques are normally preferred, this paper proposes a discontinuous pulse-width modulation algorithm (HD-PWM) to operate five-phase inverters under a single OPF. In particular, loss equalization between the remaining switches after a fault occurs is the main objective of the HD-PWM algorithm, thus preventing future faults from occurring. The efficiency and harmonic distortion of the proposed technique are compared to the well-known sinusoidal PWM by simulation and experimentation under OPF conditions. The results obtained show a great performance of the proposed modulation technique, obtaining a relevant efficiency improvement.

Near-bit apparent resistivity measurement method based on SPWM excitation

In order to improve the measurement accuracy of near-bit apparent resistivity and its measurement range, this paper excites the underground transmitting antenna by a sinusoidal pulse-width modulated (SPWM) current excitation method, which can improve the response of the receiving antenna and circuit in the resistivity measurement system under the usual square wave excitation, thus improving the measurement accuracy of near-bit apparent resistivity. In this paper, the effect of square wave, SPWM wave and sine wave excitation on resistivity measurement was studied, and the modulation algorithm and hardware control are programmed by DSP (Digital Signal Processor), and the SPWM signal is output by full-bridge inverter circuit and tuned antenna. The indoor experimental results show that the near-bit apparent resistivity measurement method based on the SPWM wave pulse excitation can achieve the measurement in the range of formation equivalent resistor value of less than 600kΩ. There is a high trend matching between near-bit apparent resistivity LWD curve and RT resistivity curve of well completion electrical logging in field tests of formation resistivity less than 2000Ω·m, which proves that the method can improve the accuracy of near-bit apparent resistivity measurement.

Sensorless Field Oriented Control of Synchronous Machines for Low and High Speeds with Space Vector Modulation-Based Direct Flux Control Measurement Sequence

During the last decade, field oriented control has often been implemented with space vector modulation due to its inherent advantages over other modulation techniques. On the other hand, direct flux control is a method that estimates the rotor electrical position of synchronous machines (e.g., permanent magnet synchronous motors) using only voltage measurements. In simple terms, direct flux control replaces position sensors by measuring the voltage difference between the star point of the synchronous machine and an artificial star point at particular instants during the switching pattern. Indeed, previous work dealt with direct flux control resorting exclusively to sinusoidal pulse width modulation and mostly in open-loop speed control schemes. This paper aims to present a space vector modulation-based direct flux control measurement sequence that can be used directly with field oriented control to perform sensorless speed control of synchronous machines. In contrast with previous publications, the direct flux control measurement sequence proposed in this paper not only extracts the direct flux control flux linkage signals with the same offset level but also obtains the phase currents needed for field oriented control without current ripple. In simple terms, the proposed direct flux control measurement sequence based on space vector modulation can be used with field oriented control to perform sensorless closed-loop speed control of synchronous machines. The sensorless speed control with the space vector modulation-based direct flux control sequence is validated for high speeds (80% of the nominal speed) and low speeds (6% of the nominal speed) using a high-fidelity four-pole synchronous machine’s simulation model implemented in ANSYS Simplorer and Maxwell.

Bipolar DC output fed grounded DC-AC converter for photovoltaic application

Introduction. In recent years the usage of electricity has increased tremendously as the electrical needs and loads got increased. Hence the researchers focused on the electricity generation from renewable sources in order to promote sustainable green environment. Owing to the lesser cost and more reliable high efficiency system with reduced use of equipments became prominent for the grid connected photovoltaic single phase systems. The novelty of this proposed converters are to reduce total power loss and to analyze the performance of the converter under various modulation index and to have lesser harmonics using sinusoidal pulse width modulation technique for both T-type and F-type inverter. Interest of the work is to merge two DC-DC converters which have same output voltage in order to have transformer less utilization of power. This has given pathway to develop a new DC-DC converter network by merging the common input nodes of CUK and SEPIC converter. Purpose. This similar structure of both converters made it easy to combine the input stages of and to get bipolar output. Methods. Here we can get bipolar output without the utilization of transformer which minimizes the overall size of the proposed system. In this paper, a combined CUK-SEPIC based grid connected transformerless inverter for photovoltaic application is suggested. Results. The suggested converter is simulated using MATLAB and the results were discussed. Further the circuit is extended with a 1 kW F-type inverter to demonstrate grid connection of the converter. Practical value. This converter can be implemented for photovoltaic applications for obtaining the bipolar DC output from the DC source.

MATLAB-Simulink environment based power quality improvement in photovoltaic system using multilevel inverter

Introduction. In this world of technical advancement, conventional resources are at the stage of destruction. To avoid such problems, we are going to use an alternative energy source namely solar by photovoltaic effect. The demand for multilevel inverters increased as they are used for different dynamic (high) voltage and dynamic (high) power appliances as they are capable of producing the output wave shape with low total harmonic distortion. Novelty. A new multilevel inverter is used in adding a (bidirectional) two way switch in between the capacitor and a traditional H-bridge module. This produces a better sine wave. By series connection of these two H-bridge modules, nine levels output voltage including zero is possible. The purpose of the proposed topology is reduction in the number of switches and it gives the good result with comparatively less power loss when it is compared with the other normal basic traditional inverters of the same output quality. Methods. In this paper, sinusoidal pulse width modulation technique is used for the working of the switches in the multilevel inverter. The results are verified by using simulation and also experimental setup is done. From the results it is observed that the proposed topology with reduced number of switches gives lower electromagnetic interference, lower harmonic distortion. Practical value. The total harmonic distortion value in the simulation is 14.4 % and practically it is 13.8 %.

H9 and H10 Transformer-Less Solar Photovoltaic Inverters for Leakage Current Suppression and Harmonic Current Reduction

Now-a-days, transformer-less inverters integrating renewable energy resources as solar photovoltaic systems are commonly employed in many grid-connected distributed energy systems in both industrial and residential settings. Transformer-less photovoltaic (TLPV) inverters have attracted increased attention due to their unique advantages, such as increased efficiency, low cost, and ease of installation. Converting fluctuating solar dc power to consistent ac power has been a difficulty in the recent decade to avoid security risks like ground fault currents and leakage currents. Leakage current minimization is one of the most crucial factors in the TLPV inverters. Different TLPV inverter topologies have been presented in the past, with leakage current being reduced by galvanic isolation on the dc or ac side of the inverter, common mode voltage (CMV) clamping, and modulation techniques. This paper proposed two novel single-phase grid-tied TLPV inverter topologies with control blocks, which can handle a wide variety of grid voltages. The proposed TLPV inverters offer very small leakage current, reduced total harmonic distortion (THD), and improved power quality. Based on the number of semiconductor devices, the proposed inverters are termed as H9 and H10 inverters. The switches are controlled using the unipolar sinusoidal pulse width modulation, which results in constant common mode voltage and reduction in leakage currents to 11.09 and 11.73 mA for the proposed H9 and H10 inverters, respectively. The proposed H9 and H10 inverters minimize the THDs to 1.62 and 2.09%, respectively. Besides, the proposed H9 and H10 inverters exhibit 98.19 and 98.12% European efficiency. The simulations are carried out on MATLAB/Simulink and the results are experimentally validated using downscale laboratory test platforms

A Comparative Study of Total Harmonic Distortion betweenTwo Topologies 27- and 31 Multi Level Inverter

In recent times, Multilevel inverters are considered an essential component of power electronics with widespread use in a wide range of high-voltage and high-power industrial and commercial applications. The use of multi-level inverters, also known as MLIs, has been preferred over conventional inverters due to the characteristics that these MLIs possess. These characteristics include low harmonic distortion caused by satisfacory performance of MLIs. This paper is concerned with analyzing harmonics to gain a deeper understanding of the performance of cascaded H-Bridge multilevel inverters (CHB-MLI). The model was constructed by using MATLAB/SIMULINK. A comparison was made between an asymmetrical cascaded 27 and 31-level multi-level inverter (MLI) by using the Phase disposition sinusoidal Pulse Width Modulation (PD-SPWM)and Phase Opposition Disposition sinusoidal Pulse Width Modulation (POD-SPWM) techniques. According to the outcomes of the simulations, 31 levels are better than 27 where Total Harmonic Distortion ( THD) in 31 levels is lower than 27 levels. The best result obtained during this study is 31 levels that use (PD-SPWM) technology, where the percentage of total harmonic distortion is small compared to the rest of the results and equal to 3.63%.

Design and performance analysis of asymmetric multilevel inverter with reduced switches based on SPWM

<span lang="EN-US">Multilevel inverters have the benefit of producing high output voltage values with little distortion. This paper deals with decreasing total harmonic distortion (THD) and providing an output voltage with various step levels switching devices. In this study, a 27-level inverter with three asymmetric H-Bridge was designed and simulated based on level shift sinusoidal pulse-width modulation and phase shift sinusoidal pulse-width modulation methods. MATLAB/Simulink has been used to create this model and test it at different types of loads. The results showed that a multilevel inverter with (PS-PWM) produces less (THD) than a multilevel with (LS-PWM), when the resistive load was used, the produced voltage and current THD in (PS-PWM) and (LS-PWM) are 3.02% and 4.30% respectively, that has resulted from the linearity between voltage and current in the resistive load. While in the case of applying an inductive load, the THD in the voltage is constant in both (PS-PWM) and (LS-PWM) methods and has the same values as the THD in a resistive load. However, the THD in the current with inductive load decreased to 2.79% in (PS-PWM) and 4.04% in (LS-PWM). Finally, these results show that the performance of the proposed power circuit with PS-PWM is better than (LS-PWM).</span>

An alternate hybrid PWM for uniform thermal sharing in single phase voltage-source inverter

The most prevalent reason for IGBT failure in voltage-source inverter (VSI) is thermal stress, which is influenced by the topology and modulation technique adopted. Hence, it is crucial to understand the impact of common sinusoidal pulse width modulation (PWM) strategies on the thermal behavior of VSI and develop improved PWM techniques. This paper presents an alternate hybrid PWM (AHPWM) switching sequence for a single-phase VSI to decrease its thermal stress and prolong its lifetime. To evaluate the number of cycles to failure of VSI, power loss and thermal analysis were conducted for VSI with AHPWM and compared with conventional PWMs. The thermal cycles experienced by IGBTs with different modulation techniques were experimentally validated using a laboratory prototype of VSI. These findings suggest that by employing AHPWM, the likelihood of VSI failure is reduced by at least one-and-a-half times, resulting in lower VSI maintenance costs.

A Predictive Current Control Strategy for a Medium-Voltage Open-End Winding Machine Drive

This paper presents a medium-voltage drive based on an open-end winding induction machine supplied by a multilevel power converter topology. The power converter consists of cascaded two-level three-phase voltage source inverters (VSI) connected to each side of the machine windings and each VSI is fed by an isolated DC supply. The topology has been previously reported in the literature as a sinusoidal pulse-width modulation operating in an open loop. In this work, a closed-loop model predictive control (MPC) strategy is proposed. MPC offers a much simpler method to control the power switches of the inverter compared to complex modulation strategies that are typically used in multilevel converters. Moreover, the advantage of reducing the common-mode voltage offered by the open-end winding configuration is fully exploited in this work. Simulation results are presented to validate the performance of the proposed topology and control method.

An Enhanced Space Vector PWM Strategies for Three Phase Asymmetric Multilevel Inverter

This work presents the two space vector pulse width modulation (SVPWM-I and SVPWM-II) strategies for eleven-level (11L) asymmetric cascaded H-bridge (CHB) multilevel inverter (MLI). Depending on the isolated structure and nonappearance of capacitor voltage balancing issues, the CHB MLI structure is favoured. These days, the SVPWM control method is accomplished superior consideration among the diverse PWM methods. In common, the SVPWM strategy is realized based on deteriorating higher-level hexagons into a lower level hexagon (2-level). Compared to the classical SVPWM strategy, the proposed SVPWM-I strategy decreases the memory and mathematical burden necessity included within the demonstration of eleven-level SVPWM devoid of losing the inverter output voltage (AC) contour by diminution the number of two-level hexagons. Also, the SVPWM-II strategy is presented, which incredibly diminishes the mathematical endeavours. The presented two SVPWM methods performed on an eleven-level asymmetric CHB multilevel inverter (MLI) by utilizing SIMULINK/MATLAB program tool and are compared with conventional sinusoidal PWM and Third harmonic injection (THI) PWM methods to confirm the proposed SVPWM methods. The proposed SVPWM methods give higher AC RMS voltage and lower harmonic distortion when compared to SPWM and THIPWM methods. To validate the presented two SVPWM control schemes, hardware results are taken on asymmetric eleven-level CHB MLI.

Three-Phase Single-Stage Bidirectional CCM Soft-Switching AC–DC Converter With Minimum Switch Count

In this article, a three-phase single-stage bidirectional ac–dc converter with low component count is proposed. The single-stage structure is configured by integrating a three-phase ac–dc converter and a three-phase dual active bridge converter. The power factor correction and bidirectional power control are performed by adjusting the modulation index of sinusoidal pulse width modulation (SPWM) and phase-shift angle between the primary and secondary bridges. The low-frequency components generated by SPWM are absorbed by fundamental blocking capacitors connected in series with transformer windings, resulting in true high-frequency isolation. The proposed converter can achieve soft-switching of all switching devices even in continuous conduction mode. A 110 Vac, 3 kW, 100 kHz prototype is implemented to validate the proposed concept and demonstrated 95.34% peak efficiency.

A Resonant DC-Link Inverter and Its Voltage Compensation Strategy

In order to solve the output voltage loss problem caused by the zero-voltage notch of resonant dc-link (RDCL) inverter and improve system efficiency, this article proposes an RDCL inverter and its voltage compensation method. The topology of this auxiliary circuit is simpler, and the resonant current is separated from the load current by parallel auxiliary switch, which reduces the current stress of the main switches. At the same time, the method is based on the conventional sinusoidal pulsewidth modulation (SPWM); this method first calculates the operation time of the auxiliary circuit based on the magnitude of the phase current, second adjusts the position of the triangular carrier according to the calculation results, and finally generates the driving signals for early turn-on and delayed turn-off, which solves the voltage loss problem and improves the voltage utilization, the output voltage is the same as that of the ideal SPWM. The working principle, parameter design conditions, and voltage compensation method are analyzed in detail in the article. Finally, a 5-kW/16 kHz prototype is created with insulated gate bipolar transistor (IGBT) as switching device, which verifies the novel resonant dc-link inverter and its modulation strategy is effective.

Design of 15 level reduced switches inverter topology using multicarrier sinusoidal pulse width modulation

In this proposed paper, multicarrier sinusoidal pulse width modulation (M-SPWM) method is implemented for design of 15 level reduced switches inverter topology. This inverter topology generates 15 level output-voltage with suitablelswitching pulse production using M-SPWM and altered level of voltages are attained with distinction of modulationlindex. The split inductor is used to diminish the harmoniclcontent and flatted output current. This type of system which contains different range of different range of voltage supplies. As a result, this inverter reduces the difficulty in gating time calculation and there is no neutral point fluctuation issue. This paper illuminates the modes of switching and minimization of stress in voltage and harmonic diminution are examined. The grades of the projected multilevel inverter (MLI) system are verified using Matlab/Simulink and dsPIC controller respectively.

A Five-Leg Three-Level Dual-Output Inverter

Classical 3-level dual-output inverter, 3-L DOI, involves two similar 3-level inverters that provides a pair of 3-phase output voltages with same or different frequencies from common input voltage source. Flexibility of either operation of the constituting inverters is evident in this DOI; but total duplication of power switches is a major drawback. State of the art coupled 3-L DOIs reduce this drawback by providing series-shared power devices between the two different 3-phase output terminals. Compared with the classical 3-L DOI, these newly developed coupled 3-L DOIs involves a smaller number of power switches; however, independent operation of the constituting inverters is lost. In this brief, a 3-L DOI is proposed which involves lesser number of power devices and provides flexibility of either operation of the constituting inverters. The 3-L DOI feature hinges on the concept of parallel-common-inverter-leg representation. At the same or varying frequency mode operation, the proposed inverter can synthesize two 3-phase output voltages. Range and relation between the two modes of operations are defined for the DOI. The control strategy is based on the single triangular carrier sinusoidal pulse-width modulation perspective. Experimental results are presented that depict the DOI inverter performances.

MATLAB Simulation of Sinusoidal Pulse Width Modulation based Three and Seven Level Current-Source Inverters

Here, a multilevel current-source inverter (MCSI) topology is analyzed. Here, the issue of constructing a novelmodular single-rating inductor MCSI has been explored. The proposed topology isbuilt with identical modules where all inductors carry the sameamount of current, simplifying the construction and operationof industrial applications with higher efficiency. A new state machine approach with a proper implementation of the phase-shifted carrier-sinusoidal pulse width modulation (PSC-SPWM) allows both current balancein all modules and effective switching-frequency minimization. The performance of the MSCI proposed is simulated with MATLAB. As a result of this topology and PSC-SPWM utilization, current balance was achieved in both main and sharing inductors, even under load and operating point changes. The switching frequency was drastically reduced with a new state machine approach, taking the advantage of the three different zero-states of the topology. The topology adopted allows operation with high efficiency by reducing the current through the inductors and the losses in the switches.

Frequency Domain Electromagnetic System Based on Unmanned Aerial Vehicles Platform for Detecting Shallow Subsurface Targets

Due to the advantages of being nondestructive, rapid, and convenient, the electromagnetic detection method has attracted growing interest in the field of shallow subsurface detection. With the rapid development of unmanned aerial vehicle (UAV) technology, the use of the UAV platform for measurement can not only improve work efficiency but also avoid the significant losses that may be caused by humans working in dangerous areas. Therefore, we propose a broadband frequency domain electromagnetic system AFEM-3 based on a UAV platform for shallow subsurface targets detection (within less than 2 m). The sensor head adopts a concentric planar coil structure with a high spatial resolution, and a bucking coil connected in reverse series with the transmitting coil is used to suppress the primary field at the receiving coil. We designed a transmitting module based on unipolar frequency multiplication sinusoidal pulse width modulation technology that can generate multi-frequency arbitrary combination transmitting waveforms with low total harmonic distortion. It can also be matched to a variety of different transmitter coils by using the same hardware circuit. In addition, the global navigation satellite system and inertial measurement unit are integrated on the sensor head. The measurement response value, position, and attitude information can be displayed in real-time through the host computer. Through the static experiment of a standard coil, we verified the consistency between the AFEM-3 system with the theory. The performance of the system was evaluated through field experiments. The experimental results show that the system can effectively detect multiple metal targets in shallow subsurface areas. For different metal targets, the AFEM-3 system can provide obvious frequency domain characteristics.