Performance comparison between PWM and SSDM techniques in interleaved boost converter

This paper proposes the pulse width modulation (PWM) technique for the five-phase open-end winding induction motor (FPOEWIM) drive fed from five-phase dual inverter (FPDI) with a single dc source. The selected method gives the advantages of reduced switching losses specifically for induction motor drives working with higher power factors with the elimination of common-mode current (CMC). The method also reduces the computational burden over the processing unit. The proposed PWM technique is explained in detail with the implementation algorithm. The algorithm is used to select the proper switching states based on the reference vector location. Further, the proposed PWM technique is analyzed for the switching losses. The reduction in the switching losses is supported with the switching loss function (SLF) analysis. The SLF for the proposed PWM technique is plotted and compared with the conventional sinusoidal PWM (SPWM) technique. The presented method is simulated and the results are given. The validation of simulated results is done using the experimental results.

The increasing integration of renewable energy sources such as solar and wind energy into modern power grids necessitates advanced power conversion technologies. Solid-state transformers (SSTs) play a critical role in this context, particularly in the low/medium-voltage dc to medium-voltage ac conversion stage. However, the performance of SST is heavily influenced by the employed pulse width modulation (PWM) technique used in switching of the power converter. Conventional PWM methods often lead to significant harmonic distortion and power losses, limiting overall system efficiency and thermal stability. This work presents an advanced trapezoidal-triangular carrier-based PWM technique designed to reduce the total harmonic distortion (THD) and power loss of the cascaded H-bridge (CHB) multilevel inverter (MLI) used in SST. The proposed approach is evaluated through comprehensive simulations in MATLAB/Simulink and PLECS, achieving an unfiltered output voltage THD of 16% and total power loss of 10.76 kW for a 300 kW CHB inverter, both improvements over existing PWM techniques. A scaled-down laboratory prototype is developed and tested to experimentally validate the simulation results. The findings confirm that the proposed PWM strategy effectively enhances the performance of the CHB inverter deployed in the SST, making it a promising solution for efficient and reliable renewable energy integration into the power grid.

Multilevel inverters have gained significant attention in recent years due to their ability to achieve higher voltage and lower harmonic distortion compared to conventional two-level inverters. Pulse width modulation (PWM) techniques play a crucial role in controlling multilevel inverters by generating the required switching signals for their power electronic devices. This paper presents a comprehensive comparative analysis of various PWM techniques employed in multilevel inverters, including sinusoidal pulse width modulation (SPWM), space vector pulse width modulation (SVPWM), carrier-based pulse width modulation (CBPWM), and selective harmonic elimination (SHEPWM). Each PWM technique's advantages, limitations, and suitability for different multilevel inverter topologies are discussed. Furthermore, recent advancements and hybrid PWM techniques are also examined to explore potential improvements in performance and efficiency. This paper aims to provide researchers, engineers, and practitioners with valuable insights into selecting the most appropriate PWM technique for their specific multilevel inverter applications, considering factors such as performance requirements, cost constraints, and ease of implementation.

The Flying Capacitor Multi Level Inverter (FCMLI) has a great advantage with respect to the availability of voltage redundancies. This work proposes a switching pattern for a modified inverter structure. It is used to improve the performance of chosen single phase five level H-bridge type FCMLI as compared to conventional FCMLI. The chosen multi level inverter is simulated for various multicarrier based Pulse Width Modulation(PWM) techniques for a resistive load. The PWM techniques include Phase Disposition (PD) PWM, Phase Opposition and Disposition (POD) PWM, Alternative Opposition and Disposition (APOD) PWM, Carrier Overlapping (CO) PWM, Phase Shift (PS) PWM and Variable Frequency (VF) PWM and the harmonics of the output voltages are observed for various modulation indices. The performance of chosen FCMLI is confirmed through MATLAB-SIMULINK based simulation. It is observed that sinusoidal reference with PODPWM provides output with relatively low distortion. Its also seen that COPWM strategy is found to perform better since it provides relatively higher fundamental RMS output voltage.

Carrier-based sinusoidal pulse-width modulation techniques for flying capacitor modular multi-level cascaded converter

This paper presents a novel switching sequence for Space Vector Advanced Pulse Width Modulation generation for Z source inverter. The Performances of an inverter depends on what type of modulation strategies is used to switch. There exists different types of classical and advanced Pulse Width Modulation (PWM) techniques to switch the traditional Voltage Source Inverter (VSI).The advanced PWM techniques are superior to classical PWM techniques in respect of load current ripple, Total Harmonic Distortions, switching losses. The same concept of advanced PWM techniques for VSI is applicable for Z-Source Inverter. This paper proposes certain vector sequences based on advanced PWM techniques for ZSI. The proposed vector sequences are analyzed in respect of load/line current ripple based on stator flux ripple concept. The superiority of the advanced PWM techniques over classical is verified by simulation study of a ZSI in PSim9.1.1 Environment for R-L and different motor load conditions.

This paper proposes the simplified pulse width modulation (PWM) strategy in the bidirectional ac/dc single-phase converter with the feed-forward control scheme. In this, the number of switching of the proposed simplified PWM strategy is reduced to one-fourth to that of the unipolar & bipolar PWM. The feed-forward control scheme is used to achieve better performance of the ac/dc converter in both the rectifier & inverter mode as compared with the conventional dual-loop control scheme. The simplified PWM strategy with feed-forward control scheme has higher efficiency than that of the unipolar PWM & bipolar PWM strategies. Also, the total harmonic distortion is less in this PWM strategy. The simulation & experiments are carried out to verify the validity of the proposed PWM strategy & control scheme.

The theoretical developments are described which form the basis for specifying the most appropriate reference signal that should be used in the carrier-based pulse width modulation (PWM) technique at any given carrier frequency and fundamental voltage. The load current distortion factor is used to compare the performances of various reference signals. The performances of the traditional carrier-based PWM techniques, using sinusoidal reference signals, are established to provide a means for comparison. A modified square-wave reference is shown to provide a low current distortion at very low carrier frequencies. A modified PWM technique can be adopted to lower the current distortion at very low carrier frequencies and also at large fundamental magnitudes. The reference signal that minimizes the current distortion is shown to be dependent upon the fundamental magnitude and the carrier frequency. >

The five-phase loads with Multi-Level Inverters (MLI) are preferred by industries in high and medium power applications due to lower switching loss, voltage stress across switches, etc. The controlling of a five-phase motor drive is done by Pulse Width Modulation (PWM) techniques. This paper discusses different multi carrier PWM techniques, such as Level Shifting Carrier (LSC) PWM and Phase Shifting Carrier (PSC) PWM techniques available for controlling the inverter drive. The simulation is carried out for all PWM techniques and load voltage, voltage THD, Common Mode Voltage (CMV), and DC-link voltages are noted and compared among the PWM techniques.

In this paper, a feedforward proportional carrier-based pulsewidth modulation (PWM) is proposed for the dc link control of the single-phase cascaded H-bridge multilevel photovoltaic inverter. The conventional carrier-based PWM techniques, such as the phase-shifted PWM and the level-shifted PWM, require multiple individual dc voltage controllers for the individual maximum power point tracking (MPPT). Thus, the control structure and the controllers' designs are quite complex. Several noncarrier-based PWM techniques, such as the feedforward space vector modulation, the sorting-algorithm-based modulation, and the lookup table-based modulation, have the capability of individual dc voltage regulation. Although these noncarrier-based PWM techniques require only one total dc voltage controller in the outer voltage loop, the implementations of them are much more complicated than those of the carrier-based PWM techniques. In this paper, with the proposed feedforward proportional carrier-based PWM, each individual modulation signal is directly generated by multiplying the current loop controller's output and the modulation signal's feedforward proportional factor. With the feedforward PWM and the total dc voltage control, the individual dc voltage regulation is achieved. This carrier-based PWM combines the strengths of both the traditional carrier-based PWM and the noncarrier-based PWM. It is not only easy for implementation, but also requires only one total dc voltage controller in the outer voltage loop. The detailed description, derivation, and analysis of this modulation are included in this paper. In addition, the simulations and experiments demonstrate the performance of the dc link control and the individual MPPT using the proposed PWM and the control strategy.

Common mode voltage (CMV) variations in the dual inverter fed induction motor drives causes unwanted shaft voltage and bearing currents resulting in reduced the life time. Single dc-link dual inverters topologies eliminate CMV but generate a poor quality of output voltage with circulating currents. Exploiting the new pulse pattern for the isolated dc-link dual inverter, new scalar pulse width modulation (PWM) methods are proposed in this paper using the freedom of selection reference signals and carrier signals. These scalar PWM techniques reduce CMV to maximum permissible limits with good quality of output voltage. PWM techniques proposed in this paper can also be extended to N-level inverter. To validate the proposed PWM techniques numerical studies are carried out in MATLAB/simulink environment.

Multilevel inverters are increasingly being used in high-power medium voltage industrial drive applications due to their superior performance compared to conventional two-level inverters. Thre are a number of Pulse width modulation (PWM) techniques applied in recent years. The most widely applied PWM techniques are Sine Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM). SPWM is the most simple modulation technique that can realize easily in analog circuit. However, it has some drawbacks such as higher total harmonic distortion (THD), lower effective DC utilization and lower switching frequency. Space vector pulse width modulation (SVPWM) is widely used because of their easier digital realization and better DC bus utilization and lower THD. The complexity is due to the difficulty in determining the reference vector location, on times calculation, and switching states selection. This paper presents a simple SVPWM algorithm for diode clamped three level inverters based on standard two-level SVPWM which can easily determine the location of reference vector, calculate the on-times, the selection of switching states. Three level diode clamped inverter (3LDCI) using space vector modulation technique has been modeled and simulated using MATLAB/SIMULINK and Origin 6.1 with a passive R-L load that can be extended to any level. Simulation results are presented to verify the proposed SVPWM control in terms of THD. The results are compared with conventional sinusoidal pulse width modulation (SPWM) where SVPWM shows better performance than SPWM in terms of THD. DOI: http://dx.doi.org/10.11591/ijpeds.v5i1.6038

Pulse width modulation (PWM) techniques involving different switching sequences are used in space vector-based PWM generation for reducing line current ripple in induction motor drives. This study proposes a hybrid PWM technique employing five switching sequences. The proposed technique is a combination of continuous PWM, discontinuous PWM (DPWM) and advanced bus clamping PWM methods. Performance of the proposed PWM technique is evaluated and compared with those of the existing techniques on a constant volts per hertz induction motor drive. In terms of total harmonic distortion in the line current, the proposed method is shown to be superior to both conventional space vector PWM (CSVPWM) and DPWM over a fundamental frequency range of 32–50 Hz at a given average switching frequency. The reduction in harmonic distortion is about 42% over CSVPWM at the rated speed of the drive.

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.

In this study, we propose a highly sensitive multichannel pH sensor that is based on an optical-fiber pulse width modulation (PWM) technique. According to the optical-fiber PWM method, the received sensing signal’s pulse width changes when the optical-fiber pH sensing-element of the array comes into contact with pH buffer solutions. The proposed optical-fiber PWM pH-sensing system offers a linear sensing response over a wide range of pH values from 2 to 12, with a high pH-sensing ability. The sensitivity of the proposed pH sensor is 0.46 µs/pH, and the correlation coefficient R2 is approximately 0.997. Additional advantages of the proposed optical-fiber PWM pH sensor include a short/fast response-time of about 8 s, good reproducibility properties with a relative standard deviation (RSD) of about 0.019, easy fabrication, low cost, small size, reusability of the optical-fiber sensing-element, and the capability of remote sensing. Finally, the performance of the proposed PWM pH sensor was compared with that of potentiometric, optical-fiber modal interferometer, and optical-fiber Fabry–Perot interferometer pH sensors with respect to dynamic range width, linearity as well as response and recovery times. We observed that the proposed sensing systems have better sensing abilities than the above-mentioned pH sensors.