The battery charging system can be implemented according to two main approaches, nominally stand-alone and integrated solutions. To develop a more compact system, researchers are exploiting the EV motor as a passive element and its inverter for energy conversion, and it is found from the literature [1],[2] that the integrated onboard charging system with traction motor is the most used technique. In recent years, the V2G systems have been well adopted in automotive industries due to some attractive features like reactive power compensation capability, current ripple reduction, and power density improvement. The bidirectional features of the PEC allow the engineers to develop compact systems via a system integration approach. A charging system with integrated converters can increase the voltage level (i.e., 400V or 800V) compared to conventional chargers. Moreover, this feature will increase the charging flexibility and interoperability, while reducing the system size via incorporating integrated structures [3]. The PECs are highly non-linear systems due to the presence of at least one non-linear switch (transistor/diode). In this paper, the small-signal linear-average (SSLA) transfer functions of a 2-level 3-phase AC/DC traction inverter and a 3-phase interleaved DC/DC converter are proposed. Furthermore, based on the SSLA model the controller parameters for the feedforward control (AC/DC) and dual-loop cascaded control (DC/DC) have been designed to achieve better stability and fast dynamic response during source and load variations. Finally, MATLAB/Simulink® is used to validate the dynamic response of the integrated charger for both G2V and V2G operations.

[1] A. Bruyere, L. De Sousa, B. Bouchez, P. Sandulescu, X. Kestelyn and ` E. Semail, “A multiphase traction fast-battery-charger drive for electric or plug-in hybrid vehicles: Solutions for control in traction mode,” 2010 IEEE Vehicle Power and Propulsion Conference, Lille, 2010, pp. 1-7.
[2] S. Lacroix, E. Laboure and M. Hilairet, “An integrated fast battery charger for Electric Vehicle,” 2010 IEEE Vehicle Power and Propulsion Conference, Lille, 2010, pp. 1-6.
[3] Bruell, Martin & Brockerhoff, Philip & Pfeilschifter, Franz & Feustel, Hans-Peter & Hackmann, Wilhelm. (2016), “Bidirectional Charger-Traction System,” World Electric Vehicle Journal. 8. 237-248. 10.3390/wevj8010237.