Analysis and Implementation of a Novel Bidirectional DC–DC Converter

ABSTRACT:  

A novel bidirectional dc–dc converter is presented in this paper. The circuit configuration of the proposed converter is very simple. The proposed converter employs a coupled inductor with same winding turns in the primary and secondary sides. In step-up mode, the primary and secondary windings of the coupled inductor are operated in parallel charge and series discharge to achieve high step-up voltage gain. In step-down mode, the primary and secondary windings of the coupled inductor are operated in series charge and parallel discharge to achieve high step-down voltage gain. Thus, the proposed converter has higher step-up and step-down voltage gains than the conventional bidirectional dc–dc boost/buck converter. Under same electric specifications for the proposed converter and the conventional bidirectional boost/buck converter, the average value of the switch current in the proposed converter is less than the conventional bidirectional boost/buck converter. The operating principle and steady-state analysis are discussed in detail. Finally, a 14/42-V prototype circuit is implemented to verify the performance for the automobile dual-battery system.

KEYWORDS:

1.      Bidirectional dc–dc converter

2.      Coupled inductor

SOFTWARE: MATLAB/SIMULINK

 CIRCUIT DIAGRAM:

Fig. 1. Proposed bidirectional dc–dc converter.

 EXPECTED SIMULATION RESULTS:

Fig. 2. Some experimental waveforms of the proposed converter in step-up

mode. (a) i_L1, i_L2, and i_L, (b) i_S1, i_S2, and i_S3. (c) v_DS1, v_DS2, and v_DS3.

Fig. 3. Dynamic response of the proposed converter in step-up mode for the

output power variation between 20 and 200 W.

Fig. 4. Some experimental waveforms of the proposed converter in step down

mode. (a) i_LL, i_L1, and i_L2, (b) i_S3, i_S1, and i_S2. (c) v_DS3, v_DS1, and v_DS2.

Fig. 5. Dynamic response of the proposed converter in step-down mode for

the output power variation between 20 and 200 W.

CONCLUSION:

This paper researches a novel bidirectional dc–dc converter. The circuit configuration of the proposed converter is very simple. The proposed converter has higher step-up and step-down voltage gains and lower average value of the switch current than the conventional bidirectional boost/buck converter. From the experimental results, it is see that the experimental waveforms agree with the operating principle and steady-state analysis. At full-load condition, the measured efficiency is 92.7% in stepup mode and is 93.7% in step-down mode. Also, the measured efficiency is around 92.7%–96.2% in step-up mode and is around 93.7%–96.7% in step-down mode, which are higher than the conventional bidirectional boost/buck converter.

REFERENCES:

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