Design and Control of a Bidirectional Power Conversion System with 3-level T-type Inverter for Energy Storage Systems

  • Sung, Won-Yong (Department of Electrical and Computer Engineering, Sungkyunkwan University) ;
  • Ahn, Hyo Min (Department of Electrical and Computer Engineering, Sungkyunkwan University) ;
  • Oh, Chang-Yeol (Power Conversion & Control Research Center, HVDC Research Division, Korea Electrotechnology Research Institute (KERI)) ;
  • Lee, Byoung Kuk (Department of Electrical and Computer Engineering, Sungkyunkwan University)
  • Received : 2017.09.18
  • Accepted : 2017.10.20
  • Published : 2018.01.01


In this paper, the design process and the control method of the power conversion system (PCS) that consists of a bidirectional DC-DC converter and a 3-level T-type inverter for an energy storage system is presented. Especially the design method of the output LCL filter for a 3-lvel T-type inverter without complex mathematical process are proposed. The validity of the control method and design process in this paper are verified through simulation and experimental analysis.

E1EEFQ_2018_v13n1_326_f0001.png 이미지

Fig. 1. Configuration of PCS for ESS

E1EEFQ_2018_v13n1_326_f0002.png 이미지

Fig. 2. Configuration of PCS controller

E1EEFQ_2018_v13n1_326_f0003.png 이미지

Fig. 3. Line-to-line voltages of the 3-level T-type inverter

E1EEFQ_2018_v13n1_326_f0004.png 이미지

Fig. 4. Phase voltages of the 3-level T-type inverter

E1EEFQ_2018_v13n1_326_f0005.png 이미지

Fig. 5. Equivalent single-phase short circuit model in high-frequency band

E1EEFQ_2018_v13n1_326_f0006.png 이미지

Fig. 6. Simulation results of PCS with designed LCL filter

E1EEFQ_2018_v13n1_326_f0007.png 이미지

Fig. 7. Simulation results of LCL filter currents

E1EEFQ_2018_v13n1_326_f0008.png 이미지

Fig. 8. 5kW prototype of the PCS with 3-level T-typeinverter and experimental environment

E1EEFQ_2018_v13n1_326_f0009.png 이미지

Fig. 9. Experimental results of the 3-level T-type inverterin discharging mode

E1EEFQ_2018_v13n1_326_f0010.png 이미지

Fig. 10. Experimental results of the 3-level T-type inverterin charging mode

E1EEFQ_2018_v13n1_326_f0011.png 이미지

Fig. 11. Experimental results of the PCS

Table 1. Control targets of the PCS

E1EEFQ_2018_v13n1_326_t0001.png 이미지

Table 2. Specification of the PCS

E1EEFQ_2018_v13n1_326_t0002.png 이미지

Table 3. Design result of the LCL filter

E1EEFQ_2018_v13n1_326_t0003.png 이미지


Supported by : Korea Institute of Energy Technology Evaluation and Planning (KETEP)


  1. C. Y. Oh, "Design and Control of Energy Storage Systems based on 3-Level T-Type Inverters," Ph.D. dissertation, Dept. Elect. Comput. Eng., Sungkyunkwan Univ., Suwon, Korea, 2016.
  2. B. Ren, X. Sun, S. An, X. Cao, Q. Zhang "Analysis and Design of an LCL Filter for the Three-level Grid Connected Inverter," 2012 IEEE 7th Int. Power Electron. and Motion Cont. Conf., Harbin, China, pp. 317-318, Jun. 2012.
  3. P. Alemi, "Analysis and Control of Grid-Connected Three-Level T-type Converters," Ph.D dissertation, Dept. Elect. Eng., Yeungnam Univ., Gyeongsan, 2014.
  4. H. M. Ahn, C. Y. Oh, E. S. Jang, and B. K. Lee, "Design of Output Filter for Grid Connected 3-level T-type Inverter," 2016 Power Electronics Annual Conference, Buan, Korea, pp.317-318, Jul. 2016.
  5. T. C. Wang, Z. Ye, G. Sinha, and X. Yuan, "Output Filter Design for a Grid-interconnected Three-Phase Inverter," PESC 2003, Acapulco, Mexico, Jun. 2003.
  6. Q. Liu, L. Peng, Y. Kang, S. Tang, Deliang Wu, and Y. Qui, "A Novel Design and Optimization Method of an LCL Filter for a Shunt Active Power Filter," IEEE Trans. Ind. Electron., vol. 61, no. 8, pp. 4000-4010, Aug. 2014.
  7. P. Channegowda and V. John, "Filter Optimization for Grid Interactive Voltage Source Inverters," IEEE Trans. Ind. Electron., vol. 57, no. 12, pp. 4106-4114, Dec. 2010.
  8. H. M. Ahn, C. Y. Oh, W. Y. Sung, J. H. Ahn, and B.K. Lee, "Analysis and design of LCL filter with passive damping circuits for three-phase grid-connected inverters," J. Elect. Eng. Tech., vol. 12, no. 1, pp. 217-224, Jan. 2017.
  9. S. Lim, and J. Choi, "LCL Filter Design for Grid Connected NPC Type Three-Level Inverter," IJRER, vol. 5, no. 1, pp. 45-53, 2015.
  10. C. Xia, X. Gu, T. Shi and Y. Yan, "Neutral-point potential balancing of three-level inverters in directdriven wind energy conversion system," IEEE Trans. Energy Convers., vol. 26, no. 1, pp. 18-19, Mar. 2011.
  11. J. Shen, S. Schrüder, and R. Roesner, "A neutral point balancing controller for three-level inverter with full power-factor range and low distortion," In IEEE Energy Conversion Congr. and Expo., pp. 3419-3426, 2011.
  12. IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems, IEEE standard 519-192, 10, May 1992.