PWM Strategy Research Articles

Multimode Carrier-Based PWM Strategy of Open-End Winding PMSM With Isolated DC Sources

Multimode Carrier-Based PWM Strategy of Open-End Winding PMSM With Isolated DC Sources

A novel PWM plus phase shift modulation strategy for three‐level isolated dual‐active‐bridge DC–DC converters

AbstractA hybrid‐three‐level isolated dual‐active‐bridge (HTDAB) DC–DC converter is widely used for grid‐interactive power converters. However, a traditional extended‐phase‐shift (EPS) modulation scheme would cause voltage‐level‐disorder (VLD) problems in HDAB DC–DC converter system because the output voltage of HTDAB would be clamped at a high‐ or low‐level during power transmission when the inductor current changes directions. Thus, the zero voltage sequence of the HTDAB cannot be stably maintained under EPS control, which not only leads to a significant difference between the actual transmission power and the target output power but also seriously affects the stability of the system control. To address this limitation, the reasons leading to VLD are analysed in detail, that is, an inappropriate PWM switching sequence at the output zero voltage level would occur under EPS control. Then, a novel PWM plus phase shift (PPS) modulation strategy is proposed, which can eliminate VLD completely. Finally, an experimental prototype is built to verify the effectiveness of the proposed PPS modulation scheme. The experimental results demonstrate that the PPS modulation method proposed in this article can effectively eliminate level disturbances and improve system stability.

Optimal Space Vector-Based Hybrid PWM Scheme in Terms of Common-Mode Voltage and Line Current Ripple

Optimal Space Vector-Based Hybrid PWM Scheme in Terms of Common-Mode Voltage and Line Current Ripple

Implementation of NLC‐SHM based novel PWM scheme on packed U‐cell multilevel inverter

AbstractThis article introduces a novel integrated nearest level controller (NLC) combined with selective harmonic mitigation (SHM) control approach aimed at efficiently suppressing lower‐order harmonics has been introduced. The proposed methodology is implemented on the PUC‐7 inverter topology, leveraging the combined benefits offered by both NLC and SHM controllers through a hybrid model. The proposed method demonstrates the capability to reduce lower‐order harmonics up to the 49th harmonic from the load voltage. The particle swarm optimization algorithm is employed to determine optimal switching angles and their corresponding nearest levels, thereby reducing implementation time, computational complexity, and overall system intricacy. The performance analysis of the proposed control strategy across various scenarios, including fluctuations in modulation index and monitoring diverse parameters such as load dynamics has been performed. This approach yields a significant reduction in total harmonic distortion in both load voltage and current. A comparative analysis between NLC, selective harmonic mitigation (SHM), and the integrated NLC‐SHM approach is carried out on the PUC‐7 inverter. The integrated SHM‐NLC control is implemented and validated using the MATLAB Simulink environment, complemented by hardware‐based experimentation, to ascertain its effectiveness.

PWM Strategy in OVM and Six-Step Regions for Open-End Winding PMSM Fed by a Dual Inverter With a Common DC Bus

PWM Strategy in OVM and Six-Step Regions for Open-End Winding PMSM Fed by a Dual Inverter With a Common DC Bus

Symmetrical Transformer Design for Suppressing Even-Order Components in CM Noise Applied to Converter With Fixed-Frequency PWM Strategy

Symmetrical Transformer Design for Suppressing Even-Order Components in CM Noise Applied to Converter With Fixed-Frequency PWM Strategy

A Modified Carrier-Based PWM Strategy for Common Mode Voltage Elimination and Neutral Point Voltage Balance in a Unidirectional Three-Level Converter for AC Motor Drives

A Modified Carrier-Based PWM Strategy for Common Mode Voltage Elimination and Neutral Point Voltage Balance in a Unidirectional Three-Level Converter for AC Motor Drives

Urgent Need of Plastic Waste Management: A Review

Plastic waste has emerged as an environmental challenge globally and has become a critical issue with widespread impacts on the environment, produces chemical pollution, creates micro-plastics, kills terrestrial wildlife, human health and animals, choking our oceans, killing and harming marine life and requires an immediate action. Plastic contaminates the air, soil, and water without appropriate collection and disposal methods, harming ecosystems and humans in the process. Plastic persists in the ecosystem for long, endangering species and dispersing pollutants. The use of plastic also fuels global warming. The majority of plastics comprises of chemicals derived from the combustion of fossil fuels including coal, oil, and gas. The paper examines types of plastic wastes and their sources; it's environmental and socio-economic impacts and the current state of PWM practices and strategies worldwide. It examines the current methods for gathering, recycling, and disposing of plastic garbage while seeking ways to improve them. Plastic pollution can modify natural processes and habitats, making ecosystems less able to adapt to climate change. This has a direct impact on the social well-being, food production, and livelihoods of millions of people. Plastic garbage is causing terrible issues and other serious health problems, especially in urban areas. These challenges have raised alarming public concerns leading to implementation of policies aimed at minimizing the amount of plastic waste generated in the environment. Additionally, it also emphasizes on importance of collaboration between governments, industries and people to achieve meaningful progress. By reviewing existing literature and data, the paper aims to focus on the complexities of PWM and highlight the areas of improvement.

A novel partitioned hybrid PWM strategy to reduce the common‐mode voltage in three‐level neutral‐point‐clamped inverters

AbstractTo reduce the common‐mode voltage (CMV) generated during the operation of the three‐level neutral‐point‐clamped (3L‐NPC) inverters, this study proposes a partitioned hybrid pulse width modulation (PHPWM) strategy. In this strategy, the three‐level vector space is divided into high‐modulation region and low‐modulation region according to the modulation index. The reference voltage is synthesized by only medium and small basic vectors with low CMV magnitude. In the low‐modulation region, a clamped level method and a five‐segment asymmetric switching sequence are adopted to reduce the loss and current distortion. In the high‐modulation region, it repartitions the vector space by medium vectors and takes a seven‐segment asymmetric switching sequence to reduce the loss and distortion slightly. The simulation results for the PHPWM strategy and the other two strategies are compared to demonstrate the superiority of PHPWM. The experiment results verify its feasibility. The results indicate that the PHPWM is capable of restricting the CMV within 1/6 of the DC‐linkage voltage and it can make a balance between efficiency and output total harmonic distortion.

A Computationally Efficient Carrier-Based PWM Strategy for Asymmetrical Six-Phase Motor Drive of Electric Vehicle With Unified Zero-Sequence Signal

A Computationally Efficient Carrier-Based PWM Strategy for Asymmetrical Six-Phase Motor Drive of Electric Vehicle With Unified Zero-Sequence Signal

PWM Strategy for the Cancellation of the Common Mode Noise Generated in a Multicell DC–AC Converter

PWM Strategy for the Cancellation of the Common Mode Noise Generated in a Multicell DC–AC Converter

Hybridized PWM Strategy for Three- and Multiphase Three-Level NPC Inverters

Hybridized PWM Strategy for Three- and Multiphase Three-Level NPC Inverters

Generalized discontinuous PWM strategy for Z-source inverters with switch losses optimization

Generalized discontinuous PWM strategy for Z-source inverters with switch losses optimization

A Real-Time Calculation PWM Strategy That Can Eliminate One Beat Delay for PMSM Driving

A Real-Time Calculation PWM Strategy That Can Eliminate One Beat Delay for PMSM Driving

A comprehensive review on recent trends and future prospects of PWM techniques for harmonic suppression in renewable energies based power converters

Research has concentrated on promoting the development of environmentally friendly energies since air pollution, energy crises, and global warming are main challenges in modern era. One effective way to reduce environmental damage is to use Renewable Energy Resources (RER). The prominence of RER is increasing due to escalating global energy challenges. Power converter development and application are closely associated to the deployment of RER. One major problem with these power converters is the presence of extremely high harmonic components in their output voltage. Various PWM techniques are employed to suppress harmonics and no singular PWM technique is universally applicable to all circumstances. Firstly, this review paper provides readers with in-depth explanation of the significance of harmonic suppression as well as presentation of several important PWM strategies. Then, the advantages and disadvantages are explored, and the methods are compared in terms of the number of harmonics suppressed by each PWM technique. Further, this review also discusses and describes harmonics suppression, PWM categorization, Single PWM, Multiple PWM, Sinusoidal PWM, Modified Sinusoidal PWM, SVPWM, Hysteresis PWM, Selective Harmonic Elimination PWM, and Multiple Carrier PWM, as well as their benefits and drawbacks. Tables with comparative assessment based on various parameters are provided for each PWM technique. Lastly, conclusion with a thorough presentation of future tendencies is provided.

A seven‐level switched‐capacitor based transformerless inverter with modified PWM strategy to enhance the performance of grid‐connected PV systems

AbstractAmong different types of transformerless photovoltaic inverters, multi‐level inverters based on switched‐capacitors (SC) are the burning topic of recent decades due to their potential advantages, such as, single source requirement, voltage boosting capability, and high power density. However, for a seven level output voltage, a conventional SC based inverter architecture uses more than two units of SC, a large amount of power switches, which then lead to capacitor voltage balancing problems. This paper presents a seven‐level switched‐capacitor transformerless inverter (SCTI), which is structured with only two SC units, ten power switches, and a single DC source. The proposed SCTI ensures voltage boosting capability, self‐voltage balancing, and low power semiconductor losses. Apart from these, a modified sinusoidal pulse width modulation (MSPWM) is also proposed in this work, which guarantees better thermal performance and low inverter output voltage THD for the proposed SCTI. The proposed SCTI along with the MSPWM is simulated in MATLAB/Simulink and PLECS computer simulation environments. A reduced scale laboratory prototype is also built and tested to ensure the feasibility of the proposed SCTI.

A Hybrid PWM Strategy for Switching Loss Reduction in Three-Level Inverters

The advanced bus-clamping PWM (ABCPWM) sequences are well known to reduce line current THD in a three-level neutral point-clamped inverter. This paper deals with ABCPWM sequences employed optimally to achieve minimum switching loss throughout the linear operating region in a three-level inverter. The work extensively analyzes the performance of these sequences in terms of inverter switching loss and compares them with centered space vector modulation PWM (CSVPWM). Based on the analysis, a hybrid PWM scheme termed as <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">switching loss reduction</i> is proposed by optimally employing ABCPWM sequences in conjunction with variation in power factors. At a given average switching frequency, the proposed hybrid scheme reduces inverter switching loss compared to CSVPWM and the recently proposed discontinuous PWM-based optimization strategy at all power factors and modulation indices. With this scheme, switching loss reduces to 22% to 36% compared to CSVPWM and a maximum of 12% reduction than the existing optimization strategy. Furthermore, the scheme gives lower harmonic distortion compared to these two existing PWM schemes near high modulation indices and near unity power factor load. The theoretical, simulated, and real-time simulation results are presented with experimental results using TMS320F28335 DSP controller for validating the proposed work.

A PSO-Based Optimized Hybrid PWM Strategy for a Binary Asymmetric Cascaded H-Bridge Photovoltaic Inverter With Single PV Source Per Phase

A PSO-Based Optimized Hybrid PWM Strategy for a Binary Asymmetric Cascaded H-Bridge Photovoltaic Inverter With Single PV Source Per Phase

Torque and flux control of induction motors fed by synchronized and symmetrical voltage pulses

SummaryThe low switching frequency in high‐power motor drives is mandatory for reducing thermal stress on power devices but often results in significant current harmonics. Synchronized space vector modulation (SynSVM), a widely used low‐carrier‐ratio PWM strategy, offers a simple implementation and reduced harmonics. However, implementing SynSVM in traditional AC motor current regulation poses challenges due to fixed voltage samples. To address this, a high‐performance control scheme based on SynSVM is proposed in this manuscript. It ensures the stator flux vector follows a predefined trajectory by integrating voltage pulses from the original SynSVM. The basic voltage vector switching is facilitated through high‐frequency monitoring and compensation of torque and flux errors, resulting in a fast torque response. Furthermore, synchronized and symmetrical voltage pulses, inherent in the original SynSVM, are equivalently generated, to effectively mitigate current harmonics. This proposed method liberates designers from the complexities of current regulation based on SynSVM. Both simulations and experiments validate the efficacy of the proposed method.

Discontinuous PWM Strategy for Reliability and Efficiency Improvements of Single-Phase Five-Level T-Type Inverter

Reliability and efficiency improvements of PV inverters have a high potential to decrease the cost of PV energy. Discontinuous PWM is an effective method to improve both the efficiency and reliability of the power devices of the single-phase five-level T-type NPC inverter. However, applying DPWM gives a negative effect on the lifetime of the DC-link capacitors and thus reduces the reliability of the inverter from the system-level reliability point of view. This paper proposes the DPWM strategy to improve the lifetime of the DC-link capacitor compared with the conventional DPWM method so that both the reliability and efficiency of the single-phase five-level T-type NPC inverter are improved. Through the proposed strategy, the lifetime of the DC-link capacitor is improved, but its negative effects on the efficiency of the inverter and the lifetime of the power devices are negligible. Therefore, the advantages of applying DPWM can be sustained. Simulation and experimental results verify the feasibility and effectiveness of the proposed DPWM strategy.