Closed-Loop Approach For Reducing Total Harmonic Distortion In A Flying Capacitor Multilevel Inverter

Vol. 1 No. 1

Year: 2013

 
Issue: Jan-Mar

Title : Closed-Loop Approach For Reducing Total Harmonic Distortion In A Flying Capacitor Multilevel Inverter

  

Author Name : S.SHANMUGA PRIYAN, K.RAMANI 

Synopsis :  

This paper concentrates on the closed loop control scheme, focusing on the reduction of total harmonic distortion (THD) in a proposed seven level flying capacitor multilevel inverter (FCMLI). Among the various multilevel inverter (MLI) topologies, FCMLI provides more advantages. The development of closed loop model for seven level FCMLI dramatically reduces the low-order harmonics and THD. Extensive simulation has been applied to compare the performance of the proposed system in closed loop control scheme with that of the open loop control scheme. In order to justify the merits of the proposed system, it is interfaced with the single phase lamp load and analysed through simulation investigations.

Fuzzy Flatness Based Control Of Three Phase Inverter Fed Induction Motor

Vol. 1 No. 1

Year: 2013

 
Issue: Jan-Mar

Title : Fuzzy Flatness Based Control Of Three Phase Inverter Fed Induction Motor 

Author Name : SASIKUMAR C, C. Muniraj 

Synopsis :  

Induction motor plays a vital role in engineering and industry. Induction motor offer a convenient means for controlling the operation of different equipment used in industry. Induction motor input supply will give from the voltage source inverter for its speed control purpose. If we connect induction motor directly to the AC supply its speed control will not applicable, so that we go inverter fed induction motor speed control. Vector control can controls the independent control of flux and torque in the induction motor. By adjusting gate pulse through vector control for vary speed of induction motor. fuzzy flatness based control is applied in the speed controller of induction motor. This method gives better efficiency of induction motor speed control. Fuzzy flatness controller method for induction motor gives better performance and reduces tracking error and reduces the torque ripple.

Comparison of Various Variable Amplitude Carrier Overlapping PWM Methods for Three Phase Five Level Cascaded Inverter

Vol. 1 No. 1

Year: 2013

 
Issue: Jan-Mar

Title : Comparison of Various Variable Amplitude Carrier Overlapping PWM Methods for Three Phase Five Level Cascaded Inverter

  

Author Name : R. Revathy, C.R.Balamurugan , S.P.Natarajan

  

Synopsis :  

This paper presents the comparison of various Carrier Overlapping Pulse Width Modulation (COPWM) Strategies for the three phase Cascaded Multi Level Inverter (CMLI). Various new schemes adopting the constant switching frequency and also variable switching frequency multicarrier control freedom degree combination concepts are developed and simulated for the chosen three phase CMLI. A three phase CMLI is controlled in this paper with Sinusoidal PWM (SPWM) reference along with Carrier Overlapping (CO) techniques and simulation is performed using MATLAB-SIMULINK. The variation of fundamental RMS output voltage and total harmonic distortion is observed for various carrier overlapping techniques. Among the various equal amplitude carrier overlapping techniques such as COPDPWM, COPODPWM, COAPODPWM, COVFPWM and COPWM-D, it is observed that COAPOD provides less total harmonic distortion (THD) and COPWM-D provides higher RMS voltage. Among the various variable amplitude carrier overlapping techniques, such as VACOPDPWM, VACOPODPWM, VACOAPODPWM, VACOVFPWM and VACOPWM-D, it is recognised that VACOAPOD provides less THD and VACOPOD provides higher RMS voltage. By comparing the equal amplitude carrier overlapping techniques with the variable amplitude carrier overlapping techniques, it is observed that VACOVFPWM provides higher fundamental RMS output voltage with relatively low distortion.

Studies on Triangular Reference with Carrier Overlapping Pulse Width Modulation Methods for Diode Clamped Five Level Inverter

Vol. 1 No. 1

Year: 2013

 
Issue: Jan-Mar

Title : Studies on Triangular Reference with Carrier Overlapping Pulse Width Modulation Methods for Diode Clamped Five Level Inverter

  

Author Name : S.Sumathi, D.Meena , C.R.Balamurugan , S.P.Natarajan

Synopsis :  

This paper presents the comparison of Variable Amplitude Pulse Width Modulation COPWM techniques for the three phase Diode Clamped Multi Level Inverter (DCMLI). A three phase DCMLI is controlled in this paper with Triangular PWM (TPWM) reference for Carrier Overlapping (CO) techniques. The variation of Total Harmonic Distortion (THD) in the inverter output voltage is observed for various modulation indices. Simulation is performed using MATLAB-SIMULINK. By comparing the various carriers overlapping technique such as COPWM-A, COPWM-B, COPWM-C and COPWM-D, it is observed that COPWM-C provide an output with relatively low distortion and COPWM-A and COPWM-D provides relatively higher fundamental RMS output voltage. By comparing the various variable amplitude carriers overlapping technique such as VACOPWM-A, VACOPWM-B, VACOPWM-C and VACOPWM-D, it is observed that VACOPWM-C provide a output with relatively low distortion and VACOPWM-D provides relatively higher fundamental RMS output voltage. Finally by comparison between the various COPWM  and variable amplitude carrier overlapping technique, it is observed that VACOPWM-C provide an output with relatively low distortion and VACOPWM-D provides relatively higher fundamental RMS output voltage.

Fault Diagnosis In Multilevel Inverter Drive Fed Induction Motor Using Wavelet Transforms

Vol. 1 No. 1

Year: 2013

 
Issue: Jan-Mar

Title : Fault Diagnosis In Multilevel Inverter Drive Fed Induction Motor Using Wavelet Transforms

  

Author Name : V. Vinothkumar, C. Muniraj

  

Synopsis :

Induction motors are becoming the most widely used motors in the industrial environments. Industry has begun to use higher power ratings, and multilevel inverter drives have become a solution for high-power applications in recent years. A multilevel inverter not only achieves high-power ratings but also enables the use of renewable energy sources. Renewable energy sources such as photovoltaic, wind, and fuel cells can be easily interfaced to a multilevel converter system for a high power application. There are many faults occurring in the multi-level inverter, in which if the type of fault and the location of the fault are known then it will be easier to clear the faults. Therefore in the proposed work a fault diagnosis method is been implemented using the discrete wavelet transform method. In this proposed work to diagnose the faults in the multi-level inverter, the output current and voltage signals of the multi-level inverter is analyzed simultaneously in both the time and frequency domains by using the discrete wavelet transforms. The discrete signal of the stator current is decomposed up to the eighth level of resolution of the discrete wavelet transforms using selected mother wavelet. The eight level of frequency band values is useful in analyzing the signals in both time and frequency domains. The simulation of this circuit is implemented by using the MATLAB software.