Dynamic Response Improvements of Parallel-Connected Bidirectional DC–DC Converters
Parallel-connected modular current-fed bidirectional DC–DC converters are used for the AC motor drive system powered by batteries with low voltage and wide voltage range. The input current ripple can be reduced significantly by employing interleaving technology not only for individual module but also for all the modules. A current-sharing control strategy is applied for the constituent modules. Double pulse width modulation plus double phase shifted control with equal duty cycles for one module can minimize the circulation loss and avoid non-active power issue. Factors affecting dynamic performance are investigated based on the small-signal modeling. The leakage inductance value is optimized in view of system reliability and better dynamic performance. Besides, to improve the dynamic performance further, feed-forward control employing optimized feed-forward coefficient based on the small-signal analysis is implemented. A 4 kW prototype composed of two bidirectional DC–DC converters is built to verify the effectiveness for the proposed control strategy in AC motor drive application with fast regenerative braking.
KeywordsParallel-connected DC–DC converter Current-sharing Dynamic performance Feed-forward control Motor drive
- 1.Chen W, Ruan X (2008) Modularization structure for series-parallel connected converters. In: IEEE Applied Power Electronics Conference and Exposition. IEEE, pp 1531–1535Google Scholar
- 5.Cheng J, Shi J, He X (2012) A novel input-parallel output-parallel connected DC–DC converter modules with automatic sharing of currents. In: IEEE Power Electronics and Motion Control Conference, pp 1871–1876Google Scholar
- 6.Sha D, You F, Wang X (2016) A high efficiency current fed semi dual active bridge DC–DC converter for low input voltage applications. IEEE Trans Ind Electron 63(4):2155–2164Google Scholar
- 9.Zhang X, Guo F, Yao C, Li H, Xu P, Wang J (2014) Small-signal modeling and controller design of an isolated quasi-switched-capacitor DC/DC converter. In: IEEE Applied Power Electronics Conference and Exposition (APEC), pp 1032–1038Google Scholar