Design and Simulation of Cascaded H-Bridge Multilevel Inverter Based DSTATCOM for Compensation of Reactive Power and Harmonics

ABSTRACT:

 

This paper presents an investigation of five-Level Cascaded H - bridge (CHB) Inverter as Distribution Static Compensator (DSTATCOM) in Power System (PS) for compensation of reactive power and harmonics. The advantages of CHB inverter are low harmonic distortion, reduced number of switches and suppression of switching losses. The DST ATCOM helps to improve the power factor and eliminate the Total Harmonics Distortion (THD) drawn from a Non-Liner Diode Rectifier Load (NLDRL). The D-Q reference frame theory is used to generate the reference compensating currents for DSTATCOM while Proportional and Integral (PI) control is used for capacitor dc voltage regulation. A CHB Inverter is considered for shunt compensation of a 11 kV distribution system. Finally a level shifted PWM (LSPWM) and phase shifted PWM (PSPWM) techniques are adopted to investigate the performance of CHB Inverter. The results are obtained through Matlab/Simulink software package.

KEYWORDS:

 

1.      DSTATCOM

2.      Level shifted Pulse width modulation (LSPWM)

3.      Phase shifted Pulse width modulation (PSPWM)

4.       Proportional-Integral (PI) control

5.      CRB multilevel inverter

6.       D-Q reference frame theory

SOFTWARE: MATLAB/SIMULINK

SCHEMATIC DIAGRAM:

Fig. 1 Schematic Diagram of a DST ATCOM

Fig. 2 Block diagram of 5-level CHB inverter model

EXPECTED SIMULATION RESULTS:

Fig. 3 five level PSCPWM output

Fig. 4 Source voltage, current and load current without DSTATCOM

Fig. 5 DC Bus Vooltage

Fig. 6 Phase-A source voltage and current

Fig. 7 Harmonic spectrum of Phase-A Source current without DSTATCOM

Fig. 8 Harmonic spectrum of Phase-A Source current with DSTATCOM

CONCLUSION:

A DSTATCOM with five level CHB inverter is investigated. Mathematical model for single H-Bridge inverter is developed which can be extended to multi H Bridge. The source voltage , load voltage , source current, load current, power factor simulation results under nonlinear loads are presented. Finally Matlab/Simulink based model is developed and simulation results are presented.

REFERENCES:

[ I ] K.A Corzine. and Y.L Familiant, "A New Cascaded Multi-level HBridge Drive:' IEEE Trans. Power.Electron .• vol. I 7. no. I. pp. I 25-I 3 I . Jan 2002.

[2] J.S.Lai. and F.Z.Peng "Multilevel converters - A new bread of converters, "IEEE Trans. Ind.Appli .• vo1.32. no.3. pp.S09-S17. May/ Jun. 1996.

[3] T.A.Maynard. M.Fadel and N.Aouda. "Modelling of multilevel converter:' IEEE Trans. Ind.Electron .• vo1.44. pp.3S6-364. Jun. I 997.

[4] P.Bhagwat. and V.R.Stefanovic. "Generalized structure of a multilevel PWM Inverter:' IEEE Trans. Ind. Appln, VoI.IA-19. no.6, pp. I OS7-1069, Nov.!Dec .. 1983.

[5] J.Rodriguez. Jih-sheng Lai, and F Zheng peng, "Multilevel Inverters; A Survey of Topologies, Controls, and Applications," IEEE Trans. Ind. Electron., vol.49 , n04., pp.724-738. Aug.2002.

Real time implementation of unity power factor correction converter based on fuzzy logic

 Abstract

In this paper an analysis and real time implementation of unity power factor correction converter (PFC) based on fuzzy logic controller is studied. A single phase AC–DC boost converter is realized to replace the conventional diode bridge rectifier. Fuzzy logic and hysteresis control techniques is implemented to improve the performance of the boost converter. The fuzzy controller is applied to DC voltage loop circuit to get better performance. The current loop is being controlled by using a PI, and hysteresis controllers. The robustness of the controller is verified via MATLAB/Simulink, the results show that the fuzzy controller gives well controller. An experiment test is implemented via a test bench based on dSPACE 1103. The experimental results show that the proposed controller enhanced the performance of the converter under different parameters variations.

Keywords

1.      Power factor correction (PFC)

2.       PLL

3.       Fuzzy logic controller (FLC)

4.       Hysteresis controller

5.       DSPACE 1103

Software: MATLAB/SIMULINK

Circuit Diagram:

Fig. 1. Single phase PFC boost converter control system

Expected Simulation Results

\

Fig.2. Diode Bridge input current

Fig.3. Line Current and its harmonic spectrum using the fuzzy controller for

DC bus

\

Fig.4. DC bus voltage based on fuzzy controller

Fig.5. PFC input current

Conclusion:

In this paper, a single-phase PFC converter DC voltage loop has been analysed. The fuzzy logic controller technique is implemented to improve the performance of the PFC converter, it is robust and efficient. Matlab/Simulink has been used to simulate the proposed techniques with successful result, the dSPACE 1103 have been used to implement the fuzzy controller in real-time. Simulation results have been presented and confirmed by the real time tests; in the same time, high efficiency is obtained. The proposed controller applied to the unity power factor give better results, a reduced harmonic distortion, and robustness control during parameter variations.

References

[1] M. Malinowski, M. Jasinski, M.P. Kazmierkowski, “Simple direct power control of three-phase PWM rectifier using space-vector modulation (DPCSVM)”, IEEE Transactions on Industrial Electronics (2004) 447–454

[2] Masashi O., Hirofumi M. “An AC/DC Converter with High Power Factor”, IEEE Transaction on Industrial Electronics, 2003, Vol 50, No. 2, pp. 356–361.

[3] Kessal A, Rahmani L, Gaubert JP, Mostefai M. “Analysis and design of an isolated single-phase power factor corrector with a fast regulation”. Electr Power Syst Res 2011; 81:1825–31.

[4] Guo L, Hung JY, Nelms RM. “Comparative evaluation of sliding mode fuzzy controller and PID controller for a boost converter.” Electr Power Syst Res 2011; 81:99–106.

[5] Kessal A, Rahmani L, Gaubert JP, Mostefai M. “Experimental design of a fuzzy controller for improving power factor of boost rectifier”. Int J Electron 2012;99 (12):1611–21.

A Solar Power Generation System With a Seven-Level Inverter

ABSTRACT:

 

This paper proposes a new solar power generation system, which is composed of a dc/dc power converter and a new seven-level inverter. The dc/dc power converter integrates a dc–dc boost converter and a transformer to convert the output voltage of the solar cell array into two independent voltage sources with multiple relationships. This new seven-level inverter is configured using a capacitor selection circuit and a full-bridge power converter, connected in cascade. The capacitor selection circuit converts the two output voltage sources of dc–dc power converter into a three-level dc voltage, and the full-bridge power converter further converts this three-level dc voltage into a seven-level ac voltage. In this way, the proposed solar power generation system generates a sinusoidal output current that is in phase with the utility voltage and is fed into the utility. The salient features of the proposed seven-level inverter are that only six power electronic switches are used, and only one power electronic switch is switched at high frequency at any time. A prototype is developed and tested to verify the performance of this proposed solar power generation system.

KEYWORDS:

 

1.      Grid-connected

2.      Multilevel inverter

3.      Pulse-width modulated (PWM) inverter

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. Configuration of the proposed solar power generation system.

EXPECTED SIMULATION RESULTS:

Fig. 2. Simulation results of the proposed solar power generation system: (a) utility voltage, (b) negative terminal voltage for adding the symmetric filter inductor, and (c) negative terminal voltage for adding the symmetric filter inductor and the extra filter C_f –R_f –C_f .

Fig. 3. Experimental results for the ac side of the seven-level inverter:

(a) utility voltage, (b) output voltage of seven-level inverter, and (c) output

current of the seven-level inverter

Fig. 4. Experimental results for the dc side of the seven-level inverter:

(a) utility voltage, (b) voltage of capacitor C2, (c) voltage of capacitor C1,

and (d) output voltage of the capacitor selection circuit.

Fig. 5. Experimental results of the dc–dc power converter: (a) ripple current of inductor, (b) ripple voltage of capacitor C2, and (c) ripple voltage of capacitor C1.

Fig. 6. Output power scan of the solar cell array.

Fig. 7. Experimental results for the MPPT performance of the proposed solar power generation system.

CONCLUSION:

This paper proposes a solar power generation system to convert the dc energy generated by a solar cell array into ac energy that is fed into the utility. The proposed solar power generation system is composed of a dc–dc power converter and a seven level inverter. The seven-level inverter contains only six power electronic switches, which simplifies the circuit configuration. Furthermore, only one power electronic switch is switched at high frequency at any time to generate the seven-level output voltage. This reduces the switching power loss and improves the power efficiency. The voltages of the two dc capacitors in the proposed seven-level inverter are balanced automatically, so the control circuit is simplified. Experimental results show that the proposed solar power generation system generates a seven-level output voltage and outputs a sinusoidal current that is in phase with the utility voltage, yielding a power factor of unity. In addition, the proposed solar power generation system can effectively trace the maximum power of solar cell array.

REFERENCES:

[1] R. A. Mastromauro, M. Liserre, and A. Dell’Aquila, “Control issues in single-stage photovoltaic systems: MPPT, current and voltage control,” IEEE Trans. Ind. Informat., vol. 8, no. 2, pp. 241–254, May. 2012.

[2] Z. Zhao, M. Xu,Q. Chen, J. S. Jason Lai, andY. H. Cho, “Derivation, analysis, and implementation of a boost–buck converter-based high-efficiency pv inverter,” IEEE Trans. Power Electron., vol. 27, no. 3, pp. 1304–1313, Mar. 2012.

[3] M. Hanif, M. Basu, and K. Gaughan, “Understanding the operation of a Z-source inverter for photovoltaic application with a design example,” IET Power Electron., vol. 4, no. 3, pp. 278–287, 2011.

[4] J.-M. Shen, H. L. Jou, and J. C. Wu, “Novel transformer-less grid connected power converter with negative grounding for photovoltaic generation system,” IEEE Trans. Power Electron., vol. 27, no. 4, pp. 1818– 1829, Apr. 2012.

[5] N. Mohan, T. M. Undeland, and W. P. Robbins, Power Electronics Converters, Applications and Design, Media Enhanced 3rd ed. New York, NY, USA: Wiley, 2003.