Three-level back-to-back converters with ESS directly connected to the lower DC-link

With the conventional circuit configuration of DC microgrids, two power conversion stages are required to transfer the energy from the Energy Storage System to loads or sources: DC/DC and DC/AC conversions. This paper proposes a new circuit configuration which puts the battery directly to the lower DC-link of 3-level back-to-back converters. The proposed circuit reduces the two-step power conversion stage to one-step. The working principle of the proposed circuit is analyzed, and the controllers for the circuit are designed. The validity of the control algorithm is verified by computer simulation.

[1]  Andrzej M. Trzynadlowski,et al.  Flexible-Voltage DC-Bus Operation for Reduction of Switching Losses in All-Electric Ship Power Systems , 2014, IEEE Transactions on Power Electronics.

[2]  Dong Chen,et al.  Control and Operation of a DC Microgrid With Variable Generation and Energy Storage , 2011, IEEE Transactions on Power Delivery.

[3]  Seung-Ki Sul,et al.  Variable-Speed Engine Generator With Supercapacitor: Isolated Power Generation System and Fuel Efficiency , 2009 .

[4]  Giorgio Sulligoi,et al.  Modeling, Simulation, and Experimental Validation of a Generation System for Medium-Voltage DC Integrated Power Systems , 2010 .

[5]  A. Tessarolo,et al.  Electric generation technologies for all-electric ships with Medium-Voltage DC power distribution systems , 2013, 2013 IEEE Electric Ship Technologies Symposium (ESTS).

[6]  Zhi-Hong Mao,et al.  Ship to Grid: Medium-Voltage DC Concepts in Theory and Practice , 2012, IEEE Power and Energy Magazine.

[7]  Seung-Ki Sul,et al.  A Naval Integrated Power System with a Battery Energy Storage System: Fuel efficiency, reliability, and quality of power. , 2015, IEEE Electrification Magazine.

[8]  Jonghoon Kim,et al.  Stable Configuration of a Li-Ion Series Battery Pack Based on a Screening Process for Improved Voltage/SOC Balancing , 2012, IEEE Transactions on Power Electronics.

[9]  Y. Khersonsky,et al.  Power electronics and future marine electrical systems , 2004, Fifty-First Annual Conference 2004 Petroleum and Chemical Industry Technical Conference, 2004..

[10]  Seung-Ki Sul,et al.  Electric Propulsion Naval Ships with Energy Storage Modules through AFE Converters , 2014 .

[11]  A. Tessarolo,et al.  Shipboard Power Generation: Design and Development of a Medium-Voltage dc Generation System , 2013, IEEE Industry Applications Magazine.