ABSTRACT:
This paper deals with a
unity power factor (UPF) Cuk converter EV (Electric Vehicle) battery charger
having a high frequency transformer isolation instead of only a single phase
front end converter used in vehicle's conventional battery chargers. The
operation of the proposed converter is defined in various modes of the
converter components i.e. DCM (Discontinuous
Conduction Mode) or CCM (Continuous Conduction Mode) along with the optimum
design equations. In this way, this isolated PFC converter makes the input
current sinusoidal in shape and improves input power factor to unity. Simulation
results for the proposed converter are shown for charging a lead acid EV battery
in constant current constant voltage (CC-CV) mode. The rated full load and
varying input supply conditions have been considered to show the improved power
quality indices as compared to conventional battery chargers. These indices
follow the international IEC 61000-3-2 standard to give harmonic free input
parameters for the proposed circuit.
KEYWORDS:
1.
UPF Cuk Converter
2.
Battery Charger
3.
Front end converter
4.
CC-CV mode
5.
IEC 61000-3-2 standard
SOFTWARE: MATLAB/SIMULINK
CIRCUIT DIAGRAM:
Fig.
1 General Schematic of an EV Battery Charger with PFC CUK Converter
EXPERIMENTAL RESULTS:
Fig.2 Simulated performance of the
isolated Cuk converter in rated condition
(a) rated input side and output side
quantities (b-c) harmonic analysis of the
current at source end
Fig.3 Simulated performance of the
isolated Cuk converter while input is
varied to 270V (a) rated input side
and output side quantities (b-c) harmonic
analysis of the current at source end
Fig.4 Simulated performance of the
isolated Cuk converter while input is
reduced to 270V (a) rated input side
and output side quantities (b-c) harmonic
analysis of the current at source end
Fig.5
Simulated performance of the isolated Cuk converter at light load
condition
(a) rated input side and output side quantities (b-c) harmonic analysis
of
the current at source end
CONCLUSION:
An isolated Cuk
converter based battery charger for EV with remarkably improved PQ indices
along with wellregulated battery charging voltage and current has been designed
and simulated. The converter performance has been found satisfactory and well
within standard for rated as well as different varying input rms value of
supply voltages. The considerably improved THD in the current at the source end
makes the proposed system an attractive solution for efficient charging of EVs
at low cost.
The proposed UPF
converter performance has been tested to show its suitability for improved
power quality based charging of an EV battery in CC-CV mode. Moreover, the cascaded
dual loop PI controllers are tuned to have the smooth charging characteristics
along with maintaining the low THD in mains current. The proposed UPF converter
topology have the inherent advantage of low ripples in input and output side due
to the added input and output side inductors. Therefore, the life cycle of the
battery is increased. MATLAB based simulation shows the performance assessment
of the proposed charger for the steady state and dynamics condition which clearly
state that the proposed charger can sustain the sudden disturbances in supply
for charging the rated EV battery load. Moreover, during whole disturbances in
supply voltage, thepower quality parameters at the input side, are maintained within
the IEC 61000-3-2 standard and THD is also very low.
REFERENCES:
[1] Limits for Harmonics Current
Emissions (Equipment current ≤ 16A per Phase), International
standards IEC 61000-3-2, 2000.
[2] Muhammad H. Rashid, “Power
Electronics Handbook, Devices, Circuits, and Applications”,
Butterworth-Heinemann, third edition, 2011.
[3] N. Mohan, T. M. Undeland, and W. P.
Robbins, Power Electronics: Converters, Applications and Design.
Hoboken, NJ, USA: Wiley, 2009.
[4] B. Singh, S. Singh, A. Chandra and
K. Al-Haddad, “Comprehensive Study of Single-Phase AC-DC Power Factor Corrected
Converters With High-Frequency Isolation”, IEEE Trans. Industrial
Informatics, vol. 7, no. 4, pp. 540-556, Nov. 2011.
[5] A. Abramovitz K. M. Smedley
"Analysis and design of a tapped-inductor buck–boost PFC rectifier with
low bus voltage" IEEE Trans. Power Electron., vol. 26 no. 9 pp.
2637-2649 Sep. 2011.
