<figure><img src="image_1.png" /></figure>

HAL
open science

# V2G and G2V plug-in and wireless charging integration in Vehicle Parking

Atharva Deshpande, Tushar Dongare, Pratik Chaudhari, Shubham Borse

► To cite this version:

Atharva Deshpande, Tushar Dongare, Pratik Chaudhari, Shubham Borse. V2G and G2V plug-in and wireless charging integration in Vehicle Parking. International Research Journal of Engineering and Technology, 2021, 8 (7). [https://hal-03298974](https://hal.science/hal-03298974)

HAL Id: hal-03298974

https://hal.science/hal-03298974

Submitted on 25 Jul 2021

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

Public Domain
# V2G and G2V plug-in and wireless charging integration in Vehicle Parking

Atharva Deshpande¹, Tushar Dongare², Pratik Chaudhari³, and Shubham Borse⁴

¹Department of Electrical Engineering, Matoshri College Of Engineering and Research Centre, Nashik, India

July 25, 2021

## Abstract

Electric vehicles (EV) are becoming a conventional preference and in coming times they will overtake conventional engines due to their countless advantages over them. The Only challenge is the limitations of battery charging infrastructure availability while traveling. Currently, an open-source charging dock employs a plug-in charging system, where the individual needs to plug in the charging cable to EV and from the charging dock. This unguarded charging dock involves risk factors like inexpertness to manually chose the required mode with personal safety and surrounding conditions, etc. therefore, in this paper, we are introducing an Automatic charging dock system, which involves automatic detection between the V2G and G2V mode of charging so as to counter the errors involve in non-expert handling procedure. This especially enhances the charging infrastructure safety in the plug-in system. Furthermore, the wireless power transfer charging system would be for Electric vehicles without a Plug-in alternative.

**Index Terms:** EV, charging dock, risk, smart detection, V2G, G2V, wireless charging.

## 1 Introduction

Vehicles are one of the most parts of today's human life. even though, it has become a basic need for humans after food clothing, and shelter. automobiles are in various forms like two-wheelers, four-wheelers, multi-wheel bus, trucks, etc. Currently, the vehicles are work with the help of fuels like petrol, diesel, etc. and the fuels are getting depleted rapidly. Also, these fossil fuels take time for their formation.

These all factors lead to an ecological imbalance

of the earth. Recently a rapid advancement has taken place in the automobile sector for the development of electric vehicles, plug-in hybrid vehicles, etc. They need batteries or battery-fuel combinations to operate. The charging of these vehicles is done with the help of charging outlets from the power grid. This electricity provided to the charging dock largely comes from the conventional sources of coal and other fossil fuels. They are also a contributor to the ecological imbalance due to limited availability and pollution. Hence, solutions need to find an alternative source of power. Renewable energy sources can be used in order to curb this problem. Apart from these vehicles also can be used as electricity-generating utilities. In this paper, we are presenting a working model representation of Grid-tied smart parking. This type of parking will help generate electricity through various renewable energy sources like solar, wind, piezo, etc. Also, the vehicle's batteries can act as an energy storage option for the load. This is known as Vehicle to Grid (V2G) or Grid to Vehicle (G2V). Furthermore, energy conservation measures are taken through human detection sensor installed at the parking lot. This sensor will also serve the purpose of security against the entry of humans into the parking lot. Also, the Radiofrequency tag system will serve against illegal entrants on the campus while opening the gate. The driverless car with a wireless charging facility is also worked out in this model project. The conventional charging system of wired connectors is also shown for easy comparison.

## 2 Vehicle to grid (V2G)

Vehicle to grid (V2G) technology can be defined as a system in which there is a capability to control, bi-directional flow of electric energy be-
tween a vehicle and the electrical grid. The integration of electric vehicles into the power grid is called the vehicle-to-grid system. Any electric-drive vehicle has within them the energy source and power electronics combining making it capable to drive the power requirements of homes and offices.

It has been calculated that 92% of the total vehicles remain parked even during peak hours. When a vehicle is not being operated, the onboard battery is connected to a nearby electrical grid via appropriate communication devices. The idea is to use the power from idle vehicles to provide load-shedding and peak shaving and many other functions. The vehicle batteries can be fully charged during low-demand hours and the flow can be reversed at any time according to the requirements. This can be fulfilled by utilizing the concept of 'smart grid' which is an electricity network capable of processing the information, manages the electricity flow to fulfill the end-users varying power demand, and is able to provide communication between generation sources and end-users. This concept works to balance the 'off-peak' and 'peak' demand. The Vehicle can get charged during off-peak hours and can sell it back to the grid during peak hours.

<figure><img src="image_2.png" /><figcaption>Figure 1: V2G system.</figcaption></figure>

## A. Advantages and Applications of V2G.

### Electrical Vehicles and PHEVs

PHEVs can be operated as a load while charging, a distributed storage, including services like reactive regulation, motor starting, or a standalone energy source such as peak sharing. Although care has to be taken while discharging the onboard batteries as excessive discharge might affect the battery life and its expectancy. The PHEV fleet is large enough and if a particular portion of the vehicle's stored energy could be tapped while parked, it would provide the power grid with large amounts of energy at a given time of the day. This section concentrates on the benefits of using PHEVs as a distributed storage.

## B. Peak sharing and other electrical benefits

The stored battery energy can be used to provide power to help balance loads by charging at

night when the demand is low (valley filling) and providing power to the grid when the demand is high (peak sharing). Peak sharing also provides additional advantages such as the reduction of a variety of unwanted factors like line losses, delay transmission, transmission congestion, etc. It also helps in reducing the stressed operation of a power system, thus adding to its longevity in terms of lasting. This leads to avoiding heavy investments in installing peaking power plants. Power regulation authorities have a good ability to predicting the peak loads (mostly during summers due to the load of the AC's).

Using hybrid vehicles as a distributed storage acts as a robust alternative to expensive and capital-demanding 'peaking plant' generators. Generally, power-seeking bodies purchase electrical energy through long-term contracts with generation companies or from spot electricity markets in the short run. Peak load periods, see the highest electricity prices. Peak shaving applications of the PHEV fleet reduces the cost of electricity during peak periods. The money saved in the case can be used to further propel the utilities of PHEVs by investing in research facilities and expanding their horizon. The average benefits from the V2G participation of an EV are estimated to range from $392 to $561 annually per vehicle. Thus PHEVs offer the power system with a flexible, controllable load and could provide load leveling during off-peak periods.

# 3 Components and Construction

## A. Copper coil

The Induction coil is an electrical device for producing an intermittent source of high voltage. An induction coil consists of a central cylindrical core of soft iron on which are wound two insulated coils: an inner or primary coil, having relatively few turns of copper wire, and a surrounding secondary coil, having a large number of turns of thinner copper wire. An interrupter is used for making and breaking the current in the primary coil automatically. This current magnetizes the iron core and produces a large magnetic field throughout the induction coil.

## B. Atmega-328 Microcontroller

The high-performance Microchip piccoPower® 8-bit AVR® RISC-based microcontroller combines 32 KB ISP Flash memory with read-while-write capabilities, 1024B EEPROM, 2 KB SRAM, 23 general purpose I/O lines, 32 general purpose working registers, three flexible timer/counters with compare modes, internal
<figure><img src="image_3.png" /><figcaption>Figure 2: Construction</figcaption></figure>

<figure><img src="image_4.png" /><figcaption>Figure 3: Copper Coil.</figcaption></figure>

and external interrupts, serial programmable USART, a byte-oriented Two-Wire serial interface, SPI serial port, a 6-channel 10-bit A/D converter (8-channels in TQFP and QFN/MLF packages), programmable watchdog timer with internal oscillator, and five software selectable power saving modes. The device operates between 1.8-5.5 volts.

### C. Multivibrator IC

When we say to an astable multivibrator circuit. Most people think of IC-555. It is famous for making pulse generators and timers. But here we are using CD4047. It is also an Astable multivibrator circuit on CMOS chips. We can use it in many circuits. Most used in an AC inverter, Square wave generator, LED flasher,

and more. It has an advantage over 555 IC that outputs a 50% duty cycle and requires a wide voltage supply. (3V to 15V).

## 4 Designing an Inverter circuit and Buck-Boost converter

### A. Inverter

In this project, we have developed a 60 W inverter circuit, which can be further increased to 100 W using a higher rating transformer and more robust heat management system. The inverter is a multivibrator IC-based MOSFET powered output for 50 Hz frequency through a battery-powered Dc supply of 12 volts. Since the Indian national grid recommends 50 Hz as the standard frequency for synchronization purposes, we have constructed the inverter to synchronize the T- box power generation with the national grid, to contribute to national power generation and meet the load demand. The voltage rating we will be getting out of this inverter is 230v AC, 50 Hz. Following is the circuit diagram for the inverter circuit.

### A. Basic Square wave generator

6V DC input to the chopper. DC-DC conversion 12V DC output from the chopper circuit is a constant DC voltage and is then input to the inverter circuit After the RC modulation for pulse width, the CD4047 multivibrator IC will
<figure><img src="image_5.png" /><figcaption>Figure 4: Square wave generator</figcaption></figure>

<figure><img src="image_6.png" /><figcaption>Figure 5: Waveform signal of three output</figcaption></figure>

give an output at its terminal.

Both this output signal from Q and Q' is then amplified using a MOSFET circuit and is then connected to the center-tapped transformer at each end. The center connection of the transformer is then connected directly to the ground connection of the DC input. This square waveform is alternating in nature, ideal only for simple applications, but it will involve too much distortion noise content. The Frequency OUPUT will not be constant and can cause damage to the connected AC appliance.

So a capacitor is added to make the circuit smooth. The step-up transformer would then convert the 12 V AC voltage to 230 V AC. One more capacitor would filter the ripple content generated due to conversion and the circuit would give full AC pure 50 Hz waveform. We use 12-battery as a power supply. The output will be a square wave, which has three forms are: I would Get The 50% duty Cycle Pin 13 is the basic frequency obtained by the VR1 and C1 across pins 1,2 & 3. Pin 10 (Q) and Pin 11(Q) shows the half frequency of the original frequency at pin 13. Both frequencies at pins 10 and pin 11

are inverted to each other phases. The inverted Outputs are 180 degrees out of phase. Three outputs have the 50% duty cycle. See the waveform signal of three outputs. We cannot adjust the duty cycle of this circuit. It always is a duty cycle of 50% that symmetry exists. Then, we can set the frequency output by adjusting VR1 and charging C1. The value of VR1 is used in a range of 1K to 1M. To Adjust to the desired frequency. And, the C1 will determine the frequency. The value is used to determine the various range. You can see this from the table below. Note: You should pick a capacitor that has a low leakage. To reduce waveform distortion and mistake frequency. The value of C1 in the circuit as Figure 1 to determine the frequency use.

$$1\mu F = 1-10Hz$$

$$0.1\mu F = 10Hz-1kHz$$

$$0.01\mu F = 100Hz-10kHz$$

And it use VR1 potentiometer is 250K. Another simple practical approach for frequency generation

$$\text{Frequency} = 1 / \text{time}$$

$$50 = 1 / R * C \quad 50 = 1 / (R * C)$$

$$50 = 1 / (R * 0.01 * 10 - 6)$$

$$50 * R * 10 - 8 = 1$$

$$R = 1 / (0.0012394)$$

$$R = 806 \text{ ohms.}$$

Thus, if we use a capacitor of 0.01 uF and set a target of 50 Hz frequency, we need to adjust our variable resistor to around 806 ohms.

## A. Stepwise conversion from 12 V DC to 230 V AC

6V DC input to the chopper. DC-DC conversion 12V DC output from the chopper circuit is a constant DC voltage and is then input to the inverter circuit After the RC modulation for pulse width, the CD4047 multivibrator IC will give an output at its terminal.

Both this output signal from Q and Q' is then amplified using a MOSFET circuit and is then connected to the center-tapped transformer at each end. The center connection of the transformer is then connected directly to the ground connection of the DC input. This square waveform is alternating in nature, ideal only for simple applications, but it will involve too much distortion noise content. The Frequency OUPUT will not be constant and can cause damage to the connected AC appliance.

So a capacitor is added to make the circuit smooth. The step-up transformer would then convert the 12 V AC voltage to 230 V AC. One more capacitor would filter the ripple content generated due to conversion and the circuit would give full AC pure 50 Hz waveform.

## B. Buck-Boost converter
<figure><img src="image_7.png" /><figcaption>Figure 6: Inverter circuit</figcaption></figure>

DC-DC converters are also known as Choppers. Here we will have a look at Buck-Boost converter which can operate as a DC-DC Step-Down converter or a DC-DC Step-Up converter depending upon the duty cycle, D.

$$V0/Vin = -D/1-D$$

We know that D varies between 0 and 1. If D > 0.5, the output voltage is larger than the input; and if D < 0.5, the output is smaller than the input. But if D = 0.5 the output voltage is equal to the input voltage. A circuit of a Buck-Boost converter is shown below.

<figure><img src="image_8.png" /><figcaption>Figure 7: Buck-Boost converter</figcaption></figure>

<figure><img src="image_9.png" /><figcaption>Figure 8: Buck-Boost converter</figcaption></figure>

## 5 Operation

In this project, a representation of a parking system for 3 vehicles is shown. The first two

vehicles would be conventional electric vehicles, which have a plug-in charging system. These vehicles would have a certain voltage across the batteries. We have considered a reference voltage of around 6 volts. So, depending on the usage the vehicles could be either over the 6v range or under it.

<figure><img src="image_10.png" /><figcaption>Figure 9: Grid to Vehicle</figcaption></figure>

When the vehicle is parked the user would need to plug in the wire from the charging port towards the vehicle. The voltage would be measured across the battery in the vehicle and sent to the microcontroller. The microcontroller is pre-programmed would compare the voltage value with the reference value of 6 volts. Depending on the difference it would decide as Grid to Vehicle (G2V) for undercharged condition (<6V) and Vehicle to Grid (V2G) for overcharged condition (>6V).

A boost converter and buck converter would be employed for that purpose respectively. The indicator would be placed at the dock to indicate the activated mode between V2G or G2V. A bidirectional relay would be employed for that purpose. The third vehicle would be a working representation for G2V mode, but with a wireless charging technique. Here, the user would not need to get outside of the vehicle for charging and plug-in purpose. The vehicle would just
<figure><img src="image_11.png" /><figcaption>Figure 10: Block Diagram</figcaption></figure>

need to be parked to facilitate the matching of charging coils closely. The Led indicator would indicate the status of wireless charging in operation.

<figure><img src="image_12.png" /><figcaption>Figure 11: Wireless Power Transfer Circuit</figcaption></figure>

Since the electrical vehicles would involve a DC (Direct current) system, it would need to convert it into an AC (Alternating Current) system to synchronize with the grid for 50 Hz. An inverter powered with the help of MOSFET and multivibrator IC would be designed for that purpose. A 230v Ac, 50 Hz electric fluorescent lamp would indicate the generation of 50 Hz AC supply.

# 6 Results

## A. Vehicle - Grid Relation on Arrival of Vehicle in Parking Space (Reference voltage = 6 V)

<table><caption>Table 1: Vehicle-Grid</caption><thead><tr><td>Car battery voltage</td><td>Status compared with reference</td><td>Condition applied</td></tr></thead><tbody><tr><td>&gt;6 V</td><td>Overcharged</td><td>V2G</td></tr><tr><td>= 6 V</td><td>Needs charging</td><td>G2V</td></tr><tr><td>&lt;6 V</td><td>Undercharged</td><td>G2V</td></tr></tbody></table>

## B. Wireless Charging

<table><caption>Table 2: Wireless power transfer</caption><thead><tr><td>Vehicle (Receiver Coil) arrived in parking slot (Transmitter Coil) with -</td><td>Charging status</td></tr></thead><tbody><tr><td>Receiver Inductive coil in field area of wireless transmitter</td><td>Wireless Charging Initiated</td></tr><tr><td>Receiver Inductive coil away from field area of wireless transmitter</td><td>Idle State</td></tr></tbody></table>

# Conclusions

In this paper, research has been done on V2G and G2V plug-in and wireless charging integration in vehicle parking. We have successfully researched and developed a working prototype model for the integration of Vehicle Parking space into the National Electricity grid with the help of the V2G and G2V concept along with
the future wireless charging concept for EV. The
following points were noted while developing the
prototype-

A.EV is not widely adopted due to poor charg-
ing infrastructure.

B. The conventional charging system is not re-
liable

C. The service providers for EV charging face
expensive land costs and initial investment in
comparison to Return on Investment.

However, with our project following points
were observed -

A.EV parking space will no longer be a burden
due to V2G technology.

B. The ROI period would be drastically reduced due to the monetization of charging in parking space.

C. Wireless charging technology ensured less
wear and tear of the charging equipment.

D. Wireless charging also ensured the safety of passengers from external weather and privacy concerns.

Acknowledgements

With profound and respect, we express our
sincere appreciation to our mentor, Mr.Pritesh
Wani sir whose systematic method of function-
ing has been our inspiration and we would also
like to thank him for his valuable suggestions
and guidance given in carrying out this work
which will be very helpful for us in future.

[4] S. Samanta and A. K. Rathore, "A single-stage universal wireless inductive power transfer system with V2G capability," 2018 International Conference on Power, Instrumentation, Control and Computing (PICC), 2018, pp. 1-5, doi: 10.1109/PICC.2018.8384783.

[5] D. J. Thrimawithana, U. K. Madawala and Yu Shi, "Design of a bi-directional inverter for a wireless V2G system," 2010 IEEE International Conference on Sustainable Energy Technologies (ICSET), 2010, pp. 1-5, doi: 10.1109/ICSET.2010.5684950.

[6] J. Lee and B. Han, "A Bidirectional Wireless Power Transfer EV Charger Using Self-Resonant PWM," in IEEE Transactions on Power Electronics, vol. 30, no. 4, pp. 1784-1787, April 2015, doi: 10.1109/TPEL.2014.2346255.

[7] D. Ahmad et al., "A Bidirectional Wireless Power Transfer for Electric Vehicle Charging in V2G System," 2019 International Conference on Electrical, Communication, and Computer Engineering (ICECCE), 2019, pp. 1-6, doi: 10.1109/ICECCE47252.2019.8940646.

[8] (http://www.v2green.com/).Retrieved 2007-10-05. Company promoting v2G technology

References

[1] H. Ben Sassi, F. Errahimi, N. Essbai and C. Alaoui, "V2G and Wireless V2G concepts: State of the Art and Current Challenges," 2019 International Conference on Wireless Technologies, Embedded and Intelligent Systems (WITS), 2019, pp. 1-5, doi: 10.1109/WITS.2019.8723851.

[2] A. P. Sample, D. T. Meyer and J. R. Smith, "Analysis, Experimental Results, and Range Adaptation of Magnetically Coupled Resonators for Wireless Power Transfer," in IEEE Transactions on Industrial Electronics, vol. 58, no. 2, pp. 544-554, Feb. 2011, doi: 10.1109/TIE.2010.2046002.

[3] J. Dai and D. C. Ludois, "Wireless electric vehicle charging via capacitive power transfer through a conformal bumper," 2015 IEEE Applied Power Electronics Conference and Exposition (APEC), 2015, pp. 3307-3313, doi: 10.1109/APEC.2015.7104827.