An adaptive modulation scheme for fundamental frequency switched multilevel inverter with unbalanced and varying voltage sources

2015 ◽  
Author(s):  
Y. C. Fong ◽  
K. W. Eric Cheng
Keyword(s):  
Fundamental Frequency ◽  
Adaptive Modulation ◽  
Multilevel Inverter ◽  
Modulation Scheme

scholarly journals Microcontroller Based Flexible Modulation Scheme of MLI Operation for Selective Lower Levels: A Knowledge Based Approach

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
R. K. Dhatrak ◽  
R. K. Nema ◽  
D. M. Deshpande
Keyword(s):  
Pulse Generation ◽  
Multilevel Inverter ◽  
Experimental Results ◽  
Modulation Scheme ◽  
Inductive Load ◽  
Medium Voltage ◽  
Knowledge Based ◽  
Common Mode Voltage ◽  
Power Modules ◽  
And Performance

In today’s industrial world multilevel inverter (MLI) got a significant importance in medium voltage application and also a very potential topic for researchers. It is experienced that studying and comparing results of multilevel inverter (MLI) at distinct levels are a costlier and time consuming issue for any researcher if he fabricate different inverters for each level, as designing power modules simultaneously for different level is a cumbersome task. In this paper a flexible quotient has been proposed to recognize possible conversion of available MLI to few lower level inverters by appropriately changing microcontroller programming. This is an attempt to obtain such change in levels through simulation using MATLAB Simulink on inductive load which may also be applied to induction motor. Experimental results of pulse generation using dsPIC33EP256MC202 demonstrate the feasibility of proposed scheme. Proposed flexible quotient successfully demonstrates that a five-level inverter may be operated as three and two levels also. The paper focuses on odd levels only as common mode voltage (CMV) can be reduced to zero and performance of drives is better than even level. Simulated and experimental results are given in paper.

WiMAX and Wi-Fi Services through Mobile Networks

2016 ◽  
pp. 160-189
Author(s):  
Sajal Saha ◽  
Angana Chakraborty ◽  
Asish K. Mukhopadhyay ◽  
Anup Kumar Bhattacharjee
Keyword(s):  
Mobile Networks ◽  
Antenna Selection ◽  
Adaptive Modulation ◽  
Path Loss ◽  
Mobile Wimax ◽  
Modulation Scheme ◽  
Coding Schemes ◽  
Radio Resources ◽  
Integrated Architecture ◽  
Restricted Mobility

WIFI and WiMAX became popular worldwide due to simplicity of installation and cost reduction compared with traditional DSL cable. The key challenge of WiFi is the restricted mobility of the user whereas mobile WiMAX (IEEE 802.16m) provides ubiquitous environment to the user. The recent challenges of WiMAX is managing radio resources (both licensed and unlicensed) efficiently through different QoS service classes, implementing proper modulation and coding schemes at PHY, proper antenna selection in MIMO to achieve better QOS. User can avail the benefits of speed and mobility through an integrated architecture comprising WiFi and WiMAX. This chapter provides an in depth performance evaluation of Mobile WiMAX and WiFi under various Modulation and Coding Schemes (MCS), cyclic prefixes and different path-loss models under integrated environment. Moreover, we present an optimized adaptive modulation scheme that senses the SNR and adaptively switches to required MCS to achieve desired level of QoS and link stability.

A Modulation Scheme for Floating Source Multilevel Inverter Topology with Increased Number of Output Levels

2016 ◽  
Vol 6 (5) ◽  
pp. 1985 ◽  
Author(s):  
Hussain M. Bassi
Keyword(s):  
Substantial Reduction ◽  
Multilevel Inverter ◽  
Modulation Scheme ◽  
Sinusoidal Wave ◽  
Switching Scheme ◽  
Multilevel Inverters ◽  
Modulation Technique ◽  
Multi Level ◽  
Inverter Topology ◽  
Switching Devices

<p>This paper presented and studied a new switching scheme for floating source multilevel inverters to produce more levels with the same number of switching devices. In the proposed scheme, the function of the dc sources, except the inner one, is to build up square wave or blocks that is close in the shape to the desired sinusoidal wave. The job of the inner switching devices is to increase the number of the levels to produce smother sinusoidal wave in the inverter output. This job can be done by adding or subtracting the value of the inner dc source to/from the blocks. The topology used in this paper is based on the conventional floating source multi-level inverter using two legs. This topology and modulation technique show substantial reduction in the total harmonics distortion when the modulation technique is the hybrid method. The performance of the proposed switching scheme in generating more levels has been evaluated by PSCAD/EMTDC simulation.</p>

scholarly journals Realization of a Generalized Switched-Capacitor Multilevel Inverter Topology with Less Switch Requirement

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1556 ◽  
Author(s):  
Anzar Ahmad ◽  
MU Anas ◽  
Adil Sarwar ◽  
Mohammad Zaid ◽  
Mohd Tariq ◽  
...  
Keyword(s):  
Output Voltage ◽  
Multilevel Inverter ◽  
Basic Unit ◽  
Modulation Scheme ◽  
Switched Capacitor ◽  
Level Control ◽  
Active Components ◽  
Proposed Model ◽  
Environment Simulation ◽  
The Cost

Conventional multilevel inverter topologies like neutral point clamped (NPC), flying capacitor (FC), and cascade H bridge (CHB) are employed in the industry but require a large number of switches and passive and active components for the generation of a higher number of voltage levels. Consequently, the cost and complexity of the inverter increases. In this work, the basic unit of a switched capacitor topology was generalized utilizing a cascaded H-bridge structure for realizing a switched-capacitor multilevel inverter (SCMLI). The proposed generalized MLI can generate a significant number of output voltage levels with a lower number of components. The operation of symmetric and asymmetric configurations was shown with 13 and 31 level output voltage generation, respectively. Self-capacitor voltage balancing and boosting capability are the key features of the proposed SCMLI structure. The nearest level control modulation scheme was employed for controlling and regulating the output voltage. Based on the longest discharging time, the optimum value of capacitance was also calculated. A generalized formula for the generation of higher voltage levels was also derived. The proposed model was simulated in the MATLAB®/Simulink 2016a environment. Simulation results were validated with the hardware implementation.

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