An Efficient Inductive Power Transfer Topology for Electric Vehicle Battery Charging

Abstract

 Recently available high-frequency power converter topologies for inductive power transfer (IPT) system utilize either zero voltage switching (ZVS) or zero current switching (ZCS) based power electronic converters while maintaining a near sinusoidal current for limited power transfer range. However, achieving ZVS or ZCS for all power switches simultaneously is still a challenging task in IPT systems. In this article, an improved zero-voltage zero-current switching (ZVZCS) IPT topology and its switching pattern are proposed. ZVS is achieved by optimizing the classical series compensation and additionally, an auxiliary network is employed to achieve ZCS. The proposed concept is verified by using MATLAB/Simulink based simulations for resistive and battery load. Finally, the practical viability of the proposed topology is validated by the results obtained using a laboratory prototype rated for 1.1kW, 85 kHz.An efficiency of 91.26% is achieved with ZVZCS for a full dynamic power transfer range of 20W–1.1 kW.

Index Terms

Battery chargers, dc–dc power converters, electric vehicles (EVs), inductive charging, soft switching, wireless power transmission.

Block diagram:

 

Fig. 1. General configuration of wireless battery charger topology.

Expected simulation results:

 

 

Fig. 2. ZCS turn-OFF for (a) S2 and (b) S4.

 

Fig. 3. Converter characteristics waveform in various operating modes.

 

Fig. 4. Input side characteristic of primary network.

 

Fig. 5. Output characteristic for BC application

Conclusion

 In this article, the voltage fed series compensation based ZVZCS topology and its tuning method for wireless electrical vehicle battery charger have been proposed. Suitable modifications were presented for the full-bridge dc–dc converter, and enhanced performance with a wide range of input variation is achieved. The need for a high-power processor is eliminated, which further reduces the overall cost. The theoretical analysis and modeling have been presented to obtain ZVZCS with reduced control complexity. The simulation results verified the ZVZCS condition of the proposed topology for a full load range. The offered solution produced less ripple in input/ output voltage and current while utilizing a low value of dc link, and filter capacitance values, respectively. An acceptable efficiency of 91.26% has been achieved for both battery and resistive loads.

References

 

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