SINGLE PHASE SINGLE STAGE BI-DIRECTIONAL LEVEL 1 ELECTRIC VEHICLE BATTERY CHARGER
A single phase single stage level-1 electric vehicle (EV) battery charger can control the power flow in both directions. The converter efficiency is high as the devices undergo ZCS which reduces switching loss in the devices. This converter does not require any intermediate DC link capacitor stage and the power density of the converter is high.
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This application is a continuation of and claims priority to U.S. patent application Ser. No. 16/638,620, entitled “Single Phase Single Stage Bi-Directional Level 1 Electric Vehicle Battery Charger,” filed Feb. 12, 2020, which is a 371 National Stage Patent Application of and claims priority to International Application No. PCT/US2018/044930, filed Aug. 2, 2018, which claims benefit and priority to U.S. Provisional Patent Application Ser. No. 62/546,955, entitled “Single Phase Single Stage Bi-Directional Level 1 Electric Vehicle Battery Charger,” filed Aug. 17, 2017, the entire contents of which are hereby incorporated by reference.
This disclosure pertains to an electric vehicle (EV) battery charging application.
The electrification of transportation has significantly increased in recent times to reduce fossil fuel consumption and greenhouse emissions. Electric vehicles (EVs) are gradually replacing the conventional internal combustion engine based vehicles. However, the increasing penetration of these EVs can have a considerable impact on the grid. Thus the chargers used for charging the batteries should have additional features like power factor correction (PFC) controllers and bidirectional power flow capabilities to minimize the impact of power quality on the grid.
Commercially available single-phase isolated AC-DC EV battery chargers can be classified into two-stage solution and single-stage solution. The two stage solution consists of a front-end PFC stage. It is followed by an isolated DC-DC stage. The frontend stage employs diode bridge rectifiers followed by a boost, buck, or buck-boost stages. Large storage elements like electrolytic capacitors are required to link these two stages. The main advantage of this two-stage solution is that the output voltage regulation and PFC control are decoupled. Thus, the PFC performance can always be ensured despite the change in input AC voltage and load power. This PFC operation enhances the power quality of the grid. Nevertheless, this two-stage solution suffers from low overall efficiency due to more number of devices. Moreover, the converter power density is limited because of the two separate stages and bulky DC link capacitors.
The alternative solution is to develop single stage AC-DC converters. The fly back converters are selected to achieve cost-effective designs because theoretically only one active switch is necessary. However, they are only suitable for lower power level because of the high-voltage and current stresses on the devices. For high-power rating single stage AC-DC converters, full bridge (FB) type topologies are preferred. In the resonant type FB and dual active bridge type FB AC-DC converters, the output voltage regulation is realized either by changing the switching frequency or by shifting the phase angle between the two bridges. These converters only use capacitors as the output filter. Thus, the voltage rating of the capacitors is lower. However, the main disadvantage of these converters is the nonlinear relation between the control parameters and the input current. Even if a complex control algorithm is applied, the grid current total harmonics distortion (THD) is large compared to conventional two-stage solution.
SUMMARYThe present disclosure relates generally to a battery charger for electric vehicles (EVs), and particularly to a single stage single phase power converter for EV charging application.
In preferred embodiments, the AC side of the proposed converter has a current-fed full bridge matrix converter that is connected to another full-bridge converter on a secondary side of a high-frequency (HF) transformer. The advantages of the proposed EV charger are its bidirectional power flow capabilities, inherent power factor correction (PFC) control, the fact that intermediate DC link capacitors are not required, soft switching capabilities in both primary and secondary side switches, improved grid current quality due to input line inductor, and the fact that the power density and efficiency of the converter is high.
The present disclosure relates to a single phase, single stage level-1 electric vehicle (EV) charger. The single phase single stage level-1 EV battery charger can control the power flow in both directions. Preferred switching sequences of the devices are also described. The converter efficiency is high as the devices undergo ZCS which reduces switching loss in the devices. This converter does not require any intermediate DC link capacitor stage. As an advantage, the power density of the converter is high.
The converter topology shown in
During Vin>0, Mia, M2a, M3a and M4a exhibit ZCS. In a similar fashion, Mode 5 to Mode 8 can also be explained. Here M1b, M2b, M3b and M4b exhibit ZCS. It is important to notice that Ck continues to conduct current even if Vbat>Vin. As a result, there is a path for the input current to flow at every switching condition. This phenomena ensures PFC for all loading conditions.
In vehicle to grid (V2G) mode, power is transferred from the battery (Vbat) to the grid (Vin). For V2G operation, battery side devices are switched in square wave mode and three level sine triangle pulse-width modulation (PWM) switching is conducted for the grid side devices. For positive input voltage (Vin>0), the operation can be divided from Mode 9 to Mode 12. Similarly, the operation can be divided from Mode 13 to Mode 16 for Vin<0. For V2G operation, the resonating capacitor Ck is removed from the circuit through a contactor.
Mode 9 to Mode 12 are continued until M5 and M6 are in the on-state in the secondary side. Once M7 and M8 are turned on, the switching cycles described above are reversed. In a similar fashion, the switching of the devices are carried out for Vin<0. As described above, all devices on the primary side undergo ZCS.
REFERENCESThe following documents and publications are hereby incorporated by reference.
F. Jauch and J. Biela, “Single-phase single-stage bidirectional isolated ZVS ac-dc converter with PFC,” in Proc. 15th Int. Power Electron. Motion Control Conf., 2012, pp. S1d-S5d.
H. S. Athab, D. D. C. Lu, A. Yazdani, and W. Bin, “An efficient singleswitch quasi-active PFC converter with continuous input current and low dc-bus voltage stress,” IEEE Trans. Ind. Electron., vol. 61, no. 4, pp. 1735-1749, April 2014.
C. Li, Y. Zhang, and D. Xu, “Soft-switching single stage isolated ac-dc converter for single-phase high power PFC applications,” in Proc. 9th Int. Conf. Power Electron. ECCE Asia, 2015, pp. 1103-1108.
R. Watson and F. C. Lee, “A soft-switched, full-bridge boost converter employing an active-clamp circuit,” in Proc. 27th Annu. IEEE Power Electron. Spec. Conf., 1996, pp. 1948-1954.
C. Qiao and K. M. Smedley, “A topology survey of single-stage power factor corrector with a boost type input-current-shaper,” in Proc. 15th Annu. IEEE Appl. Power Electron. Conf. Expo., 2000, pp. 460-467.
M. Pahlevaninezhad, P. Das, P. Jain, A. Bakhshai, and G. Moschopoulos, “A self sustained oscillation controlled three level ac-dc single stage converter,” in Proc. IEEE Appl. Power Electron. Conf. Expo., 2012, pp. 1172-1178.
M. Z. Youssef and P. K. Jain, “Analysis and design of a compact single stage ac-dc resonant converter with high power factor,” in Proc. Can. Conf. Elect. Comput. Eng., 2007, pp. 702-705.
S. Dusmez, X. Li, and B. Akin, “A fully integrated three-level isolated single-stage PFC converter,” IEEE Trans. Power Electron., vol. 30, no. 4, pp. 2050-2062, April 2015.
S. Guo, X. Ni, K. Tan, and A. Q. Huang, “Operation principles of bidirectional isolated ac/dc converter with natural clamping soft switching scheme,” in Proc. 40th Annu. Conf. IEEE Ind. Electron. Soc., 2014, pp. 4866-4872.
H. S. Ribeiro and B. Vieira Borges, “Solving technical problems on the full-bridge single-stage PFCs,” IEEE Trans. Ind. Electron., vol. 61, no. 5, pp. 2264-2277, May 2014.
H. Pinheiro, P. Jain, and G. E. Z. Joos, “Self-oscillating resonant ac/dc converter topology for input power-factor correction,” IEEE Trans. Ind. Electron., vol. 46, no. 4, pp. 692-702, August 1999.
P. K. Jain, J. E. R. Espinoza, and N. Ismail, “A single-stage zero-voltage zero-current-switched full-bridge dc power supply with extended load power range,” IEEE Trans. Ind. Electron., vol. 46, no. 2, pp. 261-270, Apr. 1999.
J. Chen, R. Chen, and T. Liang, “Study and implementation of a single-stage current-fed boost PFC converter with ZCS for high voltage applications,” IEEE Trans. Power Electron., vol. 23, no. 1, pp. 379-386, January 2008.
B. Singh, B. N. Singh, A. Chandra, K. Al-Haddad, A. Pandey, and D. P. Kothari, “A review of single-phase improved power quality ac-dc converters,” IEEE Trans. Ind. Electron., vol. 50, no. 5, pp. 962-981, October 2003.
D. Gautam, F. Musavi, M. Edington, W. Eberle, and W. G. Dunford, “An automotive on-board 3.3 kW battery charger for PHEV application,” in Proc. 2011 IEEE Veh. Power Propulsion Conf., 2011, pp. 1-6.
N. Weise and L. Doiron, “DQ current control of a bidirectional, isolated single-stage ac-dc converter,” in Proc. 29th Annu. IEEE Appl. Power Electron. Conf. Expo., 2014, pp. 1888-1893.
G. Xu, D. Sha, and X. Liao, “Input-series and output-parallel connected single stage buck type modular ac-dc converters with high-frequency isolation,” IET Power Electron., vol. 8, pp. 1295-1304, 2015.
W. Zhu, K. Zhou, M. Cheng, and F. Peng, “A high-frequency-link single phase PWM rectifier,” IEEE Trans. Ind. Electron., vol. 62, no. 1, pp. 289-298, January 2015.
M. S. Agamy and P. K. Jain, “A three-level resonant single-stage power factor correction converter: Analysis, design, and implementation,” IEEE Trans. Ind. Electron., vol. 56, no. 6, pp. 2095-2107, June 2009.
J. Everts, F. Krismer, J. Van den Keybus, J. Driesen, and J. W. Kolar, “Optimal ZVS modulation of single-phase single-stage bidirectional DAB ac-dc converters,” IEEE Trans. Power Electron., vol. 29, no. 8, pp. 3954-3970, August 2014.
Claims
1. A power converter having bidirectional power flow capabilities and inherent power factor correction (PFC) control, comprising:
- a high frequency transformer comprising a primary AC side, a secondary side, and a resonating circuit,
- wherein the primary AC side of the high frequency transformer comprises a current-fed full bridge matrix converter, wherein the current-fed full bridge matrix converter comprises eight silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) positioned in four pairs, wherein a first pair of SiC MOSFETS consists of a first A SiC MOSFET and a first B SiC MOSFET, wherein a second pair of SiC MOSFETs consists of a second A SiC MOSFET and a second B SiC MOSFET,
- wherein a third pair of SiC MOSFETs consists of a third A SiC MOSFET and a third B SiC MOSFET, and wherein a fourth pair of SiC MOSFETs consists of a fourth A SiC MOSFET and a fourth B SiC MOSFET,
- wherein the secondary side of the high frequency transformer comprises a full bridge matrix converter, wherein the full bridge matrix converter comprises four SiC MOSFETs, wherein the four SiC MOSFETs consist of a fifth SiC MOSFET, a sixth SiC MOSFET, a seventh SiC MOSFET, and an eighth SiC MOSFET, and
- wherein the resonating circuit comprises a leakage inductor of the high frequency transformer and a capacitor.
2. An electric vehicle (EV) battery charger comprising the power converter of claim 1.
3. The electric vehicle (EV) battery charger of claim 2, further comprising an input source and a battery.
4. One or more photovoltaic cells comprising the power converter of claim 1.
Type: Application
Filed: Dec 7, 2021
Publication Date: Mar 24, 2022
Applicant: University of Houston System (Houston, TX)
Inventors: Kaushik Rajashekara (Pearland, TX), Parthasarathy Nayak (Houston, TX), Sumit Kumar Pramanick (Houston, TX)
Application Number: 17/543,919