scholarly journals Output Voltage Ripple Reduction in a Symmetric Multistage-Stacked Boost Architecture (MSBA) Converter

Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 394
Author(s):  
Julio C. Rosas-Caro

This article proposes a different operation mode in a recently proposed converter, the multistage-stacked boost architecture (MSBA) converter working under the symmetric operation mode. The operation mode of the converter is analyzed with a modified pulse width modulation (PWM) scheme, in which the switching function of transistors is obtained from an interleaved scheme. The results show that the modified PWM results in a similar operation of the converter, with a reduced output voltage ripple, without increasing the switching frequency. A mathematical model of the converter is provided, the output voltage ripple calculation is performed in the traditional, and the modified PWM scheme, simulation, and experimental results are provided to verify the operation mode and the obtained equations.

Author(s):  
Sreenivasappa Bhupasandra Veeranna ◽  
Udaykumar R Yaragatti ◽  
Abdul R Beig

The digital control of three-level voltage source inverter fed high power high performance ac drives has recently become a popular in industrial applications. In order to control such drives, the pulse width modulation algorithm needs to be implemented in the controller. In this paper, synchronized symmetrical bus-clamping pulse width modulation strategies are presented. These strategies have some practical advantages such as reduced average switching frequency, easy digital implementation, reduced switching losses and improved output voltage quality compared to conventional space vector pulse width modulation strategies. The operation of three level inverter in linear region is extended to overmodulation region. The performance is analyzed in terms THD and fundamental output voltage waveforms and is compared with conventional space vector PWM strategies and found that switching losses can be minimized using bus-clamping strategy compared to conventional space vector strategy. The proposed method is implemented using Motorola Power PC 8240 processor and verified on a constant v/f induction motor drive fed from IGBT based inverter.


Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7643
Author(s):  
Lingling Cao ◽  
Jiefeng Lin ◽  
Shikai Chen ◽  
Yuanmao Ye

Multilevel inverters have been widely used in various industrial applications such as renewable energy generation and electric vehicles. An improved circuit of symmetrical cascaded switched-capacitor multilevel inverter is proposed so that the reactive power is absorbed by its power supply instead of capacitors. Then, a special hybrid pulse width modulation strategy combing level-shifted pulse width modulation (LS-PWM) and phase-shifted pulse width modulation (PS-PWM) was developed for the inverter. With this modulation algorithm, the power between cascaded units is automatically balanced, and the voltage of the capacitor in each unit is also automatically balanced to the dc input voltage. In addition, the optimized capacitor voltage ripple makes it possible to use a smaller capacitor to produce a better output voltage waveform. Theoretical analysis, simulation and experimental results show that the equivalent switching frequency of the cascaded multilevel inverter is twice the original frequency so that the output voltage harmonics are only distributed near even multiples of the carrier frequency.


2021 ◽  
Vol 280 ◽  
pp. 05009
Author(s):  
Ihor Kozakevych ◽  
Roman Siyanko

The work is devoted to the study of performance of a multilevel electric energy converter using phase-shifted pulse-width modulation. Equations describing the state of a dynamic system multilevel converter - load are investigated and a mathematical model of the system in Matlab / Simulink environment has been constructed. Variants of implementation of phase-shifted pulse-width modulation systems from the point of view of influence on harmonics of output voltage and magnitude of circulating current in the converter are investigated.


Author(s):  
M. H. Yatim ◽  
A. Ponniran ◽  
A. N. Kasiran

<span>This paper presents a proposed modified pulse width modulation – low frequency triangular (MPWM-LFT) switching strategy for minimization of voltage THD with implementation of asymmetric multilevel inverter (AMLI) topology on the reduced number of switching devices (RNSD) circuit structure. Principally, MPWM-LFT able to produce optimum angle of the output voltage level in order to minimize total harmonic distortion (THD). In this study, 5-level reduced number of switching devices circuit structure is selected as a circuit configuration for asymmetric (7-level structure) multilevel inverter. For switching strategy, MPWM used low switching frequency in producing signal and needs higher output voltage levels to achieve low total harmonic distortion. In contrast, sinusoidal pulse width modulation used high switching frequency in order to minimize total harmonic distortion. By optimizing angle at the output voltage using MPWM-LFT switching strategy, the voltage THD is lower as compared to MPWM and SPWM switching strategies. MPWM-LFT switching strategy obtains 11.6% of voltage THD for the 7-level asymmetric topology as compared to MPWM and SPWM switching strategies with the voltage THD are 21.5% and 17.5% respectively from the experimental works.</span>


2014 ◽  
Vol 626 ◽  
pp. 141-149 ◽  
Author(s):  
Shibu J.V. Bright ◽  
V. Suba ◽  
S. Ramkumar ◽  
S. Jeevananthan

The pulse width modulation (PWM) strategy employed in the voltage source inverter (VSI) not only control the magnitude of the output voltage but also the quality. Performance evaluations of such strategies are done in terms of fundamental voltage, total harmonic distortion (THD), switching losses etc. (primary indices) and also in terms of acoustic noise, electromagnetic interference (EMI), harmonic spread factor, distribution of harmonic power etc. (secondary indices). Multilevel inverter (MLI) has become unanimous choice in medium and high power applications due to their superior performance compared to three level inverters. The conventional Sub-Harmonic PWM (SHPWM) scheme and its variations offer the output voltage spectrum with high intensity harmonic components around the switching frequency; it will end with cluster harmonic with high acoustic noise. The first objective of this paper is to investigate harmonic spreading effects of existing multilevel inverter (MLI) strategies. Secondly the developing innovative PWM strategies for MLIs based on modified reference and carrier functions, which were proved for superior the primary indices at three-level VSI. Thorough simulation study of Pulse width modulation strategies such as SHPWM, inverted sine carrier PWM, MWM PWM, third harmonic injection PWM, triplen harmonic injection PWM, analog space vector PWM, trapezoidal PWM and discontinuous PWM for a cascaded multilevel inverter, are presented with results of primary and secondary indices. Hence, the PWM strategies of MLI are evaluated for harmonic spreading effect first time and a guide line for a beginner to select the PWM scheme for MLI fed drive systems is stenciled.


2014 ◽  
Vol 573 ◽  
pp. 143-149
Author(s):  
N. Ismayil Kani ◽  
B.V. Manikandan ◽  
Prabakar Perciyal

—This The Pulse Width Modulation (PWM) DC-to-AC inverter has been widely used in many applications due to its circuit simplicity and rugged control scheme. It is however driven by a hard-switching pulse width modulation (PWM) inverter, which has low switching frequency, high switching loss, high electro-magnetic interference (EMI), high acoustic noise and low efficiency, etc. To solve these problems of the hard-switching inverter, many soft-switching inverters have been designed in the past. Unfortunately, high device voltage stress, large dc link voltage ripples, complex control scheme and so on are noticed in the existing soft-switching inverters. This proposed work overcomes the above problems with simple circuit topology and all switches work in zero-voltage switching condition. Comparative analysis between conventional open loop, PI and fuzzy logic based soft switching inverter is also presented and discussed. Keywords—Zero voltage switching, Inverter, Dc link, PI controller, Fuzzy logic system control ,Modulation strategy, Soft switching


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Jagabar Sathik ◽  
Dhafer J. Almakhles ◽  
N. Sandeep ◽  
Marif Daula Siddique

AbstractMultilevel inverters play an important role in extracting the power from renewable energy resources and delivering the output voltage with high quality to the load. This paper proposes a new single-stage switched capacitor nine-level inverter, which comprises an improved T-type inverter, auxiliary switch, and switched cell unit. The proposed topology effectively reduces the DC-link capacitor voltage and exhibits superior performance over recently switched-capacitor inverter topologies in terms of the number of power components and blocking voltage of the switches. A level-shifted multilevel pulse width modulation scheme with a modified triangular carrier wave is implemented to produce a high-quality stepped output voltage waveform with low switching frequency. The proposed nine-level inverter’s effectiveness, driven by the recommended modulation technique, is experimentally verified under varying load conditions. The power loss and efficiency for the proposed nine-level inverter are thoroughly discussed with different loads.


Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 853 ◽  
Author(s):  
Abdul Yasin ◽  
Muhammad Ashraf ◽  
Aamer Bhatti

The key issue in the implementation of the Sliding Mode Control (SMC) in analogue circuits and power electronic converters is its variable switching frequency. The drifting frequency causes electromagnetic compatibility issues and also adversely affect the efficiency of the converter, because the proper size of the inductor and the capacitor depends upon the switching frequency. Pulse Width Modulation based SMC (PWM-SMC) offers the solution, however, it uses either boundary layer approach or employs pulse width modulation of the ideal equivalent control signal. The first technique compromises the performance within the boundary layer, while the latter may not possess properties like robustness and order reduction due to the absence of the discontinuous function. In this research, a novel approach to fix the switching frequency in SMC is proposed, that employs a low pass filter to extract the equivalent control from the discontinuous function, such that the performance and robustness remains intact. To benchmark the experimental observations, a comparison with existing double integral type PWM-SMC is also presented. The results confirm that an improvement of 20% in the rise time and 25.3% in the settling time is obtained. The voltage sag during step change in load is reduced to 42.86%, indicating the increase in the robustness. The experiments prove the hypothesis that a discontinuous function based fixed frequency SMC performs better in terms of disturbances rejection as compared to its counterpart based solely on ideal equivalent control.


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