The Study on Harmonic Characteristics of Three-Phase SPWM Inverter

2011 ◽  
Vol 117-119 ◽  
pp. 1779-1783
Author(s):  
Hong Juan Zhang ◽  
Yong Xing Hou

Through using dual Fourier transform quantitative analysis and harmonic loss calculation on the output voltage of three phase voltage-Sinusoidal Pulse Width Modulation (SPWM) inverter, a valid harmonic inhibition scheme is presented. Carrier frequency is reasonably selected to eliminate low times harmonics, harmonics of carrier frequency times and triple frequency sideband. Analysis of fast Fourier transform is achieved in MATLAB. Simulation results show that harmonics are effectively inhibited, output voltage waveform is improved and voltage distortion factor is decreased from1.16% to 0.71%.

2013 ◽  
Vol 392 ◽  
pp. 409-412
Author(s):  
Xian Bin Dai ◽  
Xiao Hua Yuan ◽  
Wei Du

This paper introduces the working principle of the research of simulation in the main circuit of Static Var Generator based on Cascade H-Bride and takes the three-phase Static Var Generator based on cascade H-Bride with rated capacity 10kVar,rated voltage 380V for example to proceed the MATLAB simulation. The research shows that the more amount of cascade H-Bride, the more number of output voltage levels in the main circuit of Static Var Generator, the smaller value of voltage waveform distortion factor, and the less harmonic content be inject in electric network, which improves power index.


The Multilevel Z sources Inverter have been documented as attractive topologies used for elevated voltage adaptation. As the digit of levels improved, the synthesized set of steps output waveform have many ladder, imminent the preferred sine waveform but the major weakness of MLI be its amplitude of ac output voltage is imperfect to DC input sources voltage summing up. To conquer this drawback seven level cascading symmetric multilevel inverter based Z source inverter have been projected. This work focuses on different multi-carrier sinusoidal PWM scheme for the seven level three phase Z source symmetric cascading inverter. Performance parameters of seven level three phase Z source symmetric cascading inverter has been analyzed. A simulation circuit model of seven level three phase Z source symmetric cascading inverter urbanized using MATLAB/SIMULINK and its presentation have been urbanized.


Circuit World ◽  
2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anbarasan P. ◽  
Krishnakumar V. ◽  
Ramkumar S. ◽  
Venkatesan S.

Purpose This paper aims to propose a new MLI topology with reduced number of switches for photovoltaic applications. Multilevel inverters (MLIs) have been found to be prospective for renewable energy applications like photovoltaic cell, as they produce output voltage from numerous separate DC sources or capacitor banks with reduced total harmonic distortion (THD) because of a staircase like waveform. However, they endure from serious setbacks including larger number of capacitors, isolated DC sources, associated gate drivers and increased control difficulty for higher number of voltage levels. Design/methodology/approach This paper proposes a new three-phase multilevel DC-link inverter topology overpowering the previously mentioned problems. The proposed topology is designed for five and seven levels in Matlab/Simulink with gating pulse using multicarrier pulse width modulation. The hardware results are shown for a five-level MLI to witness the viability of the proposed MLI for medium voltage applications. Findings The comparison of the proposed topology with other conventional and other topologies in terms of switch count, DC sources and power loss has been made in this paper. The reduction of switches in proposed topology results in reduced power loss. The simulation and hardware show that the output voltage yields a very close sinusoidal voltage and lesser THD. Originality/value The proposed topology can be extended for any level of output voltage which is helpful for sustainable source application.


2012 ◽  
Vol 588-589 ◽  
pp. 454-457
Author(s):  
Xin Jun Li

The three-phase voltage type SPWM inverter output voltage and current harmonic and its generation rule is discussed. And put forward a new easy to implement harmonic suppression strategy, the method through the correct choice of the carrier frequency and the sinusoidal wave superimposed on a three wave makes saddle shaped wave, to produce a corresponding SPWM waveform control inverter switch on-off thus improving the output waveform. Mathematical analysis shows that is helpful to reduce the output voltage THD ( waveform distortion factor ), improved harmonic current loss and torque characteristics, the simulation results prove the validity of these measures and practical.


Author(s):  
Sanjeev Kumar ◽  
◽  
H.K. Verma ◽  
M.P.S. Chawla ◽  
◽  
...  

A hybrid structured asymmetric switching capacitor multilevel inverter (ASC-MLI) is suggested in this work. The notion behind presenting this topology is to reduce the device count and DC sources as compared with conventional MLI. The step by step operating mode of single phase ASC-MLI is presented and by doing slight modifications the same configuration is used in three phase utility application and electric drive. The proposed configurations utilize major benefits of self-voltage balancing capability of capacitor voltage, which is independent from different load type and modulations index. To generate the switching pulse for corresponding switches the multi-carrier based sinusoidal pulse width modulation (MCS-PWM) technique is used; in addition to this simulation result are obtained using MATLAB/Simulink 2016b software version. Simulation results of an induction motor drive connected as three phase load highlights good performance of 17-level MLI.


Author(s):  
Nor Azizah Mohd Yusoff ◽  
Azziddin M. Razali ◽  
Kasrul Abdul Karim ◽  
Auzani Jidin ◽  
Tole Sutikno

<p>This paper presents an analysis of virtual-flux direct power control (VFDPC) technique for the three-phase pulse width modulation (PWM) ac-dc converter. The proposed VFDPC is developed by assuming the grid voltage and converter line filters quantities are related to a virtual three-phase ac motor. The controller works with less number of sensors by eliminating the voltage sensors used for measuring the three-phase grid voltage. The grid virtual flux which is proportional to the grid voltage will be estimated from the information of converter switching states, line current, and dc-link output voltage. Several analyses are performed in order to study the steady state and dynamic performance of the converter, particularly during the load and DC voltage output reference variations. The proportional integral (PI) controller at the outer voltage control loop of VFDPC is tuned properly and the entire PWM ac-dc converter system is simulated using MATLAB/Simulink to ensure the dc output voltage follow the desired output voltage under steady state and dynamic conditions. Ac-dc converter utilizing the proposed VFDPC is able to generate three-phase input current waveforms that are almost sinusoidal with low harmonics contents which is less than 5% and near unity power factor (<em>pf</em>) operation.</p>


Author(s):  
G. V. V. Nagaraju ◽  
G. Sambasiva Rao

<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>


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