Level-shifted Sinusoidal Pulse Width Modulation Research Articles

A Single-Stage Closed Loop Control of SC-Based Inverter

This work presents a closed loop five-Level grid-connected inverter. The inverter is based on the switched capacitor approach. The suggested architecture has a lower number of components and is able to maintain a voltage balance across the various capacitors in the system. The construction that has been presented offers a number of benefits, including the capacity to produce five-level voltage output, lower current THD, and enhanced efficiency. Additionally, leakage-current in the circuit is eliminated due to the common grounding configuration. The current injected into the grid is controlled by a PI controller. As a result, a carefully controlled current of the desired quality can be injected into the system using just one renewable energy source. In order to test the suggested topology, the level-shifted sinusoidal pulse width modulation scheme is adopted. The design of switched capacitors as well as the computation of power loss in switches is offered. The performance of this suggested inverter topology is evaluated in comparison to other topologies that are recently presented in the literature. In addition, the power losses and efficiency are calculated using thermal modeling of the topology in PLECS software. MATLAB-2018/Simulink is used to simulate and analyze the PV-connected grid system.

A Modified Design of Multilevel Inverter Using Sinusoidal Pulse Width Modulation

Multi-level Inverter technology is gaining popularity and been a momentous choice in the region of the high-power medium voltage-energy control. Producing high quality without the use of more count of switches and thus the development of such low switch Multi Level Inverter (MLI) topologies are concentrated more in this current research. These have the ability to meet the increasing demand of power rating using improved power quality through subsequent reduction in harmonic distortion. MLIs have their impression in the fields of large electric drives, traction, renewable energy conversion, electric vehicles, active power filters, HVDC and facts. The multi-level inverter generate a quasi sinusoidal voltage from various level of DC voltage. The proposed inverter is a 15-level cascaded MLI inverter and 23-level being its extension. These both are created by using the Level Shifted-Sinusoidal Pulse Width Modulation (LS-SPWM) technique. Reduction in the Total Harmonic Distortion (THD) has been the chief aim of the selected pattern. It gave a superior result in the THD. The proposed configuration overcomes the drawbacks of MLIs such as complexity, need of great number of power devices. It has less number of switches resulting in more levels of count from 15 to 23. Thus reduces the cost and gets better reliability for medium power applications. The proposed topology is simulated using MATLAB/SIMULINKR2013a and is verified.

Three-phase five-level CHB inverter fed induction motor for renewable applications

<p><span lang="EN-US">This paper presents the three-phase CHB inverter fed induction motor suitable for renewable energy source applications. Normally, all present existing multilevel inverters produce multilevel output, but the number of components required is more, bulk in size, more in cost. Which are more burdens to small capacity renewable sources. These challenges are eliminated in CHB inverter. This CHB mainly consisting of one DC source, one capacitor and eight switches in each phase. To generate a five-level output in phase to ground voltage, it is required to maintain the capacitor voltage (V2) at fifty percent of the DC source voltage (V1). This capacitor voltage is regulated by a sensor less voltage regulating technique. The sensor less voltage regulation works without any sensor devices. We can implement this technique with very less cost compared to other techniques. The sensor less voltage regulation is realized by level-shifted sinusoidal pulse width modulation. The simulation results show a very good dynamic performance. Controller maintains the capacitor voltage at fifty percent of the source voltage irrespective of main source voltage changes and load changes. Inverter generates a five-level wave at the output from line to ground and seven-level wave from line to line with fewer Harmonic. It is implemented in matlab/simulink and showing good dynamic performance.</span></p>

Reduced Switch Count Based Single Source 7L Boost Inverter Topology

The new inverter topologies based on switched capacitor concept with voltage boosting ability are attractive for the low voltage applications. Such low voltage requirements allow a single-stage dc-ac power conversion, improving overall system performance, reliability and power density. This brief proposes a new multilevel inverter topology based on the switched-capacitor (SC) with a single source of dc voltage. The proposed topology is ideal for low voltage renewable energy applications. Seven-level (7L) output voltage is accomplished with triple voltage gain using two switched capacitors and 10 switches. Other major features of the proposed topology are self-voltage balancing of capacitor voltages, reduced number of switches with lower voltage stress and generation of negative voltage levels without using backend H-bridge. To show the advantages of the proposed topology, a detailed comparison with other similar topologies with seven-level single-source configuration has been accomplished in this brief. The proposed topology has been tested using the traditional level-shifted sinusoidal pulse width modulation (LS-PWM) technique. This brief includes various experimental results with different operating conditions to prove the performance of the proposed topology.

Asymmetrical Cascade Multilevel Inverter Design using Modified Level Shift Pulse Width Modulation

Multi-level inverter technology emerges as extremely significant choice in region of high-power medium voltage energy control. The multi-level inverter(MLI) generate a quasi sinusoidal voltage from various level of dc voltage. The proposed inverter design for 21 level cascaded MLI inverter by using Level Shifted-Sinusoidal Pulse Width Modulation (LS-SPWM) technique with new carrier and evaluate the Total Harmonic Distortion(THD). The proposed inverter design has the least number of components to lessen the cost and get better reliability of converter for medium power applications. The presented control techniques are applicable to cascaded H-bridge 21 level inverter to get better voltage regulation and thereby, lead the better efficiency,reliability and economic improvement. The selected pattern gave superior result in Total Harmonic distortion.