Power Factor Improvement in Modified Bridgeless Landsman Converter Fed EV Battery Charger

Abstract

 This work deals with the design and implementation of a new charger for battery operated electric vehicle (BEV) with power factor improvement at the frontend. In the proposed configuration, the conventional diode converter at the source end of existing electric vehicle (EV) battery charger, is eliminated with modified Landsman power factor correction (PFC) converter. The PFC converter is cascaded to a flyback isolated converter, which yields the EV battery control to charge it, first in constant current mode then switching to constant voltage mode. The proposed PFC converter is controlled using single sensed entity to achieve the robust regulation of DC-link voltage as well as to ensure the unity power factor operation. The proposed topology offers improved power quality, low device stress, low input and output current ripple with low input current harmonics when compared to the conventional one. Moreover, to demonstrate the conformity of proposed charger to an IEC 61000-3-2 standard, a prototype is built and tested to charge a 48V EV battery of 100Ah capacity, under transients in input voltage. The performance of the charger is found satisfactory for all the cases.

Keywords

1.      Battery Operated Electric Vehicle

2.      Battery Charger

3.      Power Factor Improvement

4.      Modified Landsman Converter

5.      Power Quality

Conclusion

An improved EV charger with modified BL Landsman converter followed by a flyback converter has been proposed, analyzed, and validated in this work to charge an EV battery with inherent PF Correction. The design and control of the proposed EV charger in DCM mode have offered the advantage of reduced number of sensors at the output. Moreover, the proposed BL converter has reduced the input and output current ripples due to inductors both in input and output of the converter. A prototype has been developed and operation of the charger has been verified by the experimental results under steady state and sudden fluctuations in input voltage. The results from the hardware validation show that the performance of proposed charger is found satisfactory for improved power quality based charging of EV battery. Moreover, the input current THD is reduced as low as 4.3% to meet the recommended IEC 61000-3-2 standard guidelines for power quality. Therefore, proposed BL converter fed charger aims at cost effective, reliable and suitable option to replace the conventional lossy and inefficient EV battery charger

References

[1] Wencong Su, Habiballah Eichi, Wente Zeng and Mo-Yuen Chow, “A survey on the electrification of transportation in a smart grid environment,” IEEE Transactions Industrial Informatics, vol. 8, no. 1, pp. 1-10, Feb. 2012.

[2] Ching Chuen Chan, “The state of the art of electric, hybrid, and fuel cell vehicles,” Proc. IEEE, vol. 95, no. 4, pp. 704–718, Apr. 2007

[3] Kaushik Rajashekara, “Present status and future trends in electric vehicle propulsion technologies,” IEEE J. Emerg. Sel. Topics Power Electronics., vol. 1, no. 1, pp. 3–10, Mar. 2013.

[4] Juan C. Gomez and Medhat M. Morcos, “Impact of EV battery chargers on the power quality of distribution systems,” IEEE Transactions Power Del., vol. 18, no. 3, pp. 975–981, Jul. 2003.

[5] Luca Solero, “Nonconventional on-board charger for electric vehicle propulsion batteries,” IEEE Transactions Vehicular Technology, vol. 50, no. 1, pp. 144-149, Jan 2001