ABSTRACT:
In
this paper, a solar PV (Photovoltaic) array, a battery energy storage (BES), a
diesel generator (DG) set and grid based EV charging station (CS) is utilized
to provide the incessant charging in islanded, grid connected and DG set
connected modes. The charging station is primarily designed to use the solar
photovoltaic PV array and a BES to charge the electric vehicle (EV) battery.
However, in case of exhausted storage battery and unavailable solar PV array
generation, the charging station intelligently takes power from the grid or DG
(Diesel Generator) set. However, the power from DG set is drawn in a manner
that, it always operates at 80-85% loading to achieve maximum fuel efficiency
under all loading conditions. Moreover, in coordination with the storage
battery, the charging station regulates the generator voltage and frequency without
a mechanical speed governor. It also ensures that the power drawn from the grid
or the DG set is at unity power factor (UPF) even at nonlinear loading.
Moreover, the PCC (Point of Common Coupling) voltage is synchronized to the
grid/ generator voltage to obtain the ceaseless charging. The charging station
also performs the vehicle to grid active/reactive power transfer, vehicle to
home and vehicle to vehicle power transfer for increasing the operational
efficiency of the charging station. The operation of the charging station is
experimentally validated using the prototype developed in the laboratory.
KEYWORDS:
1. EV Charging Station
2. Solar PV Generation
3. Power Quality
4. DG Set
SOFTWARE:
MATLAB/SIMULINK
CONCLUSION:
An
implementation of PV array, storage battery, grid and DG set based charging
station has been realized for EV charging. The presented results have verified
the multimode operating capability (islanded operation, grid connected and DG
set connected) of the CS using only one VSC. Test results have also verified
the satisfactory operation of charging station under different steady state
conditions and various dynamics conditions caused by the change in the solar
irradiance level, change in the EV charging current and change in the loading.
The operation of charging station as a standalone generator with good quality
of the voltage, has been verified by the presented results. Whereas, test
results in DG set or grid connected mode, have verified the capability of ANC
based control algorithm to maintain the power exchange with the grid at UPF or
the optimum loading of the DG set. Moreover, the islanded operation, grid
connected and DG set connected operations along with the automatic mode
switching have increased the probability of MPP operation of the PV array and
optimum loading of DG set along with increasing the charging reliability. The
IEEE compliance operation of the charging station with voltage and current THD
always less than 5% verifies the effectiveness of the control. Form the above
mentioned point, it can be concluded that this charging station with the
presented control have the capability to utilize the various energy sources
very efficiently and provides the constant and cost effective charging to the
EVs.
REFERENCES:
[1] International Energy Agency-Global EV Outlook 2018- Towards cross-modal electrification. [Online] Available: https://webstore.iea.org /download/direct/1045?fileName=Global_EV_Outlook_2018.pdf
[2] International Energy Agency- Renewables 2O18 - Analysis and Forecasts to 2O23 [Online]. Available: https://webstore.iea.org/ download/summary/2312?fileName=English-Renewables-2018ES.pdf.
[3] J. Ugirumurera and Z. J. Haas, “Optimal Capacity Sizing for Completely Green Charging Systems for Electric Vehicles,” IEEE Trans. Transportat. Electrificat.vol. 3, no. 3, pp. 565-577, Sept. 2017.
[4] G. R. Chandra Mouli, J. Schijffelen, M. van den Heuvel, M. Kardolus and P. Bauer, “A 10 kW Solar-Powered Bidirectional EV Charger Compatible With Chademo and COMBO,” IEEE Trans, Power Electron., vol. 34, no. 2, pp. 1082-1098, Feb. 2019.
[5] V. Monteiro, J. G. Pinto and J. L. Afonso, “Experimental Validation of a Three-Port Integrated Topology to Interface Electric Vehicles and Renewables With the Electrical Grid,” IEEE Trans. Ind. Informat., vol. 14, no. 6, pp. 2364-2374, June 2018
