Diode Clamped Three Level Inverter Using Sinusoidal PWM

 

ABSTRACT:

An inverter is a circuit which converts dc power into ac power at desired output voltage and frequency. The ac output voltage can be fixed at a fixed or variable frequency. This conversion can be achieved by controlled turn ON & turn OFF or by forced commutated thyristors depending on applications. The output voltage waveform of a practical inverter is non sinusoidal but for high power applications low distorted sinusoidal waveforms are required. The filtering of harmonics is not feasible when the output voltage frequency varies over a wide range. There is need for alternatives. Three level Neutral Point Clamped inverter is a step towards it.

KEYWORDS:

  1. Harmonics
  2. Inverter
  3. THD
  4. PWM

 SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Figure1.Diode clamped three level inverter

EXPECTED SIMULATION RESULTS:

 

 Figure2. Upper triangular pulse width modulation

Figure3. lower triangular pulse width modulation

Figure4. three level voltage waveform

Figure5.Matlab model of three level inverter feeding induction motor

 Figure 6. stator waveform of three level inverter

 CONCLUSION:

In normal inverters odd harmonics are present which causes distortion of the output waveform. By using the “THREE LEVEL DIODECLAMPED INVERTER” we can eliminate some number of harmonics hence increasing the efficiency of the inverter.

 REFERENCES:

[1] A.Mwinyiwiwa, Zbigneiw Wolanski, ‘Microprocessor Implemented SPWM for Multiconverters with Phase-Shifted Triangle Carriers’ IEEE Trans. On Ind. Appl., Vol. 34, no. 3, pp 1542-1549, 1998.

[2] J. Rodriguez, J.S. Lai, F. Z. Peng, ’ Multilevel Inverters: A Survey of Topologies, Controls and Applications’, IEEE Trans. On Ind. Electronics, VOL. 49, NO. 4, pp. 724-738, AUGUST 2002

[3] D. Soto, T. C. Green, ‘A Comparison of High Power Converter Topologies for the Implementation of FACTS Controller’, IEEE Trans. On Ind. Electronics, VOL. 49, NO. 5, pp. 1072-1080, OCTOBER 2002.

[4] Muhammad H. Rashid, Power Electronics: Circuits, Devices and Applications, Third edition, Prentice Hall of India, New Delhi, 2004.

[5] Dr. P. S. Bimbhra, Power Electronics, Khanna Publishers, Third Edition, Hindustan Offset Press, New Delhi-28, 2004.

Simulation Analysis of SVPWM Inverter Fed Induction Motor Drives

ABSTRACT:

In this paper represent the simulation analysis ofspace vector pulse width modulated(SVPWM) inverter fedInduction motor drives. The main objective of this paper isanalysis of Induction motor with SVPWM fed inverter and harmonic analysis of voltages & current. for control of IMnumber of Pulse width modulation (PWM) schemes are used tofor variable voltage and frequency supply. The most commonlyused PWM schemes for three-phase voltage source inverters(VSI) are sinusoidal PWM (SPWM) and space vector PWM(SVPWM). There is an increasing trend of using space vectorPWM (SVPWM) because of it reduces harmonic content involtage, Increase fundamental output voltage by 15% & smoothcontrol of IM. So, here present Modeling & Simulation ofSVPWM inverter fed Induction motor drive inMATLAB/SIMULINK software. The results of Total HarmonicDistortion (THD), Fast Fourier Transform (FFT) of current areobtained in MATLAB/Simulink software.

KEYWORDS:

  1. Inverter
  2. VSI
  3. SPWM
  4. SVPWM
  5. IM drive

 SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

  Figure 1.Simulation Block Diag. of SVPWM Three level inverter with IM load

EXPECTED SIMULATION RESULTS:

 

Figure 2 Inverter Line voltage

Figure 3 Inverter Line currents

Figure 4 Stator Current

Figure 5 Rotor Current

Figure 6 Mechanical Speed

Figure 7 Torque

Figure 8 Harmonic (FFT) Analysis of Line current

 CONCLUSION:

The SVPWM Inverter fed induction motor driveModeling & then simulation is done in MATLAB/SIMULINK 12. From simulation results of THD & FFT analysis concluded that SVPWM technique is better overall PWM techniques which gives less THD in Inverter current 4.89%., which under the permissible limit.

 REFERENCES:

[1] A. R. Bakhshai H. R. Saligheh Rad G. Joos, space vectormodulation based on classification method in three-phasemulti-level voltage source inverters, IEEE 2001

[2] Bimal K Bose, modern power electronics and ac drives © 2002Prentice hall ptr.

[3] Dorin O. Neacsu, space vector modulation –An introductiontutorial at IECON2001 IEEE 2001

[4] Fei Wang, Senior Member, “Sine-Triangle versus Space-VectorModulation for Three-Level PWM Voltage-Source Inverters”,IEEE transactions on industry applications, vol. 38, no. 2,March/April 2002. The 27th Annual Conference of the IEEEIndustrial Electronics Society

[5] F. Wang, Senior, Sine-Triangle vs. space vector modulation forthree-level voltage source inverters ,IEEE 2000