ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
Soft-Switching Current-Fed Push–Pull Converter for 250-W AC Module Applications ABSTRACT: In this paper, a soft-switching single-inductor push– pull converter is proposed. A push–pull converter is suitable for low-voltage photovoltaic ac module systems, because the step-up ratio of the high-frequency transformer is high, and the number of primary-side switches is relatively small. However, the conventional push–pull converter does not have high efficiency because of high-switching losses due to hard switching and transformer losses (copper and iron losses) as a result of the high turn ratio of the transformer. In the proposed converter, primary-side switches are turned ON at the zero-voltage switching condition and turned OFF at the zero-current switching condition through parallel resonance between the secondary leakage inductance of the transformer and a resonant capacitor. The proposed push–pull converter decreases the switching loss using soft switching of the primary switches. In addition, the turn ratio of the transformer can be reduced by half using a voltage-doubler of secondary side. The theoretical analysis of the proposed converter is verified by simulation and experimental results.
KEYWORDS: 1. Current-fed push–pull converter 2. Photovoltaic (PV) ac module 3. Soft-switching
SOFTWARE: MATLAB/SIMULINK
For Simulation Results of the project Contact Us
Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245 CONTROL BLOCK DIAGRAM:
Fig. 1. Control block diagram of the dc–dc converter and dc–ac inverter using a microcontroller.
For Simulation Results of the project Contact Us
Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245 EXPECTED SIMULATION RESULTS:
Fig. 2. (a) Carriers and a reference for PWM. (b) Waveforms of primary switch S1 . (c) Waveforms of primary switch S2 .
For Simulation Results of the project Contact Us
Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
Fig. 3. (a) Boost inductor current iLbst . (b) Resonant capacitor voltage vC r .
For Simulation Results of the project Contact Us
Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
Fig. 4. (a) Waveforms of tracking the MPP. (b) PWM according to MPPT. (c) Start flag of MPPT.
For Simulation Results of the project Contact Us
Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
Fig. 5. Current and voltage waveforms of switch S1 according to ZVS and ZCS.
Fig. 6. Waveforms of resonant capacitor voltage and boost inductor current.
For Simulation Results of the project Contact Us
Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245
ELECTRICAL PROJECTS USING MATLAB/SIMULINK Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245 CONCLUSION: In this paper, the soft-switching single-inductor push–pull converter for PV ac module applications is proposed. Soft switching was confirmed at each part, and MPPT is performed for extracting the maximum power from the PV module. Switches of the primary side operate in the ZVS condition at turn-off and in the ZCS condition at turn-on. The proposed converter maintains a Vo of 400 V to provide ac 220 Vrms for dc–ac inverters. The maximum efficiency is 96.6%. These results were confirmed by simulation and verified by a 250-W experimental setup.
REFERENCES: [1] S. B. Kjaer, J. K. Pedersen, and F. Blaabjerg, “A review of single-phase grid-connected inverters for photovoltaic modules,” IEEE Trans. Ind. Appl., vol. 41, no. 5, pp. 1292–1306, Sep. 2005. [2] S. B. Kjaer, J. K. Pedersen, and F. Blaabjerg, “Power inverter topologies for photovoltaic modules: A review,” in Proc. IEEE. Ind. Appl. Conf., vol. 2, Oct. 2002, pp. 782–788. [3] Y. Xue, L. Chang, S. B. Kjaer, J. Bordonau, and T. Shimizu, “Topologies of single-phase inverters for small distributed power generators: An overview,” IEEE Trans. Power Electron., vol. 19, no. 5, pp. 1305–1314, Sep. 2004. [4] R. Gonzalez, J. Lopez, P. Sanchis, and L. Marroyo, “Transformerless inverter for singlephase photovoltaic systems,” IEEE. Trans. Power Electron., vol. 22, no. 2, pp. 693–697, Mar. 2007. [5] T. Shimizu,K.Wada, andN.Nakamura, “Flyback-type single-phase utility interactive inverter with power pulsation decoupling on the DC input for an AC photovoltaic module system,” IEEE Trans. Power Electron.,, vol. 21, no. 5, pp. 1264–1272, Sep. 2006.
For Simulation Results of the project Contact Us
Gmail:asokatechnologies@gmail.com, Website: http://www.asokatechnologies.in
0-9347143789/9949240245