Electric Vehicle Charging Method for SmartHomes/Buildings with a Photovoltaic System
Electric Vehicle Charging Method
Homes/Buildings with a
• Due to the increased penetration of electric vehicles (EVs) and photovoltaic
(PV) systems, additional application for home/building energy management
system (EMS) is needed to determine when and how much to charge an
electric vehicle in an individual home/building.
• This paper presents a smart EV charging method for smart homes/buildings
with a PV system. The paper consists of two parts: EV charging scheduling
algorithm for smart homes/buildings and implementation of prototype
application for home/building EMS.
• The proposed EV charging algorithm is designed to determine the optimal
schedules of EV charging based on predicted PV output and electricity
• The implemented prototype application for home/building EMS can
provide EV charging schedules according to user preferences
• Due to the increased penetration of electric vehicles (EVs) and
photovoltaic (PV) systems, additional application for home/building
energy management system (EMS) is needed to determine when and
how much to charge an electric vehicle in an individual home/building.
This paper presents a smart EV charging method for smart
homes/buildings with a PV system.
• The proposed EV charging algorithm is designed to determine the
optimal schedules of EV charging based on predicted PV output and
• The implemented prototype application for home/building EMS can
provide EV charging schedules according to user preferences.
• There is no existing method is available for smart electrical
• Thus the way we go for the proposed system. In this we
desired one efficient alternating method for smart charging.
Scope of the project
• The main objective of this project is charge the electric
vehicle battery using AC power supply or solar panel
depend upon the weather condition.
• If the weather is normal Electrical vehicle is charged
through panel else it will charge through direct AC supply.
• In this propose system, microcontroller is connected with
LCD, temperature sensor, Humidity sensor, solar panel and
• First we get weather information about that particular area.
If the weather condition is normal it checks the
surrounding weather by using the temperature and
• If it is normal the Electrical vehicle is charged through
panel else it will charge through direct AC supply.
• If the weather condition is abnormal it check the sensor
status it will directly charge through the AC line.
Number of Units (Modules)
Power supply unit
Device driver unit
Power supply unit
• The supply of 5V DC is given to the system which is converted
from 230V AC supply. Firstly, the step down transformer will
be used here for converting the 230V AC into 12V AC.
• The microcontroller will support only the DC supply, so the AC
supply will be converted into DC using the bridge rectifier.
• The output from the filter is given to the 7805 voltage regulator
which will convert the 12V DC into 5V DC.
• So the pure 5V DC is getting as the output from the power
• In this project the Pic microcontroller is used in the Home
• In this we use pic microcontroller with sensor network here
we using Temperature sensor is used to monitor the inside
and outside room temperature.
• Depends upon the temperature we will control the fan or AC
in the home section.
• This whole status is displayed in the LCD monitor
• MAX232 is used to convert the voltage level,
which is compatible for the PC for receive and
storing the information from the cars.
Device Driver Unit
Device Driver Unit
The relay is used to control the supply to the electrical device depend upon
The LCD is used to display the information received in the Zigbee
transceiver. The Temperature of the environment also displayed on LCD.
The temperature sensor is used to monitor the surrounding
The humidity sensor is used to sense the environment humidity
Given Input and Expected output
Power Supply Unit:
• In the power supply unit the 230V AC is converted into 5V DC.
230V AC supply is given as the input to the power supply unit.
The 5V DC supply is getting as the output from the power
Microcontroller unit controls the devices connected with this (Max232, relay
with the motor, and LCD).
Inputs to the controller is temperature sensor output that is surrounding
temperature and humidity.
This sensor output analog values, this values are convert into digital using
analog to digital converter and we get the Digital value corresponding to the
Relay with DC motor, LCD these are the output devices used in this project.
DC motors are act as a load .The LCD is used to display the status of the
Communication devices send or receive the data’s in wire/wireless to the
• Given Input:
The max232 is used in collecting center. The information received by
the Zigbee transmitter is given to the max232 via serial port of the processor
in binary format.
The output of max232 is coming from receive pin as 0’s and 1’s which
will be the input for PC for uploading the data.
LCD is used as the display unit in this project.
The 5V DC supply is given as the input for LCD. In contains the 3 command
lines and 8 data lines. These 11 lines will be connected with the
The commands and datas will be given as the hexadecimal format from the
The data from the command lines will initialize the LCD. The data from the
data lines will be displayed in the LCD.
Relay and battery
In this project the battery is load and which is connected with
the relay unit.
The 12V DC supply is given as the input to the coil of the relay.
5V DC is given as the triggering input to the transistor for switching
It contains two terminals, they are normally open, normally closed.
After giving the input for the relay, the coil gets magnetize and the
magnetic tip will be moved from normally closed to normally open
depend upon the sensor value.
The battery charging using the relay from either Solar or AC power
Circuit Diagram Explanation
• In this fig shown the circuit diagram of electric vehicle charging method
for smart home/building with a PV system.
• In this circuit diagram used components are PIC µc, Temperature sensor,
humidity sensor, LCD Display, Relays, Power supply,MAX232 etc.
• Humidity & temperature sensor are connected to the PIC µc pin 2 & 3
• LCD is connected in µc . Total 14 pins are available in LCD. Three
command pins, Eight data pins & 3 supply pins shown in fig.
• One relay is connected in direct AC line and another relay is connected in
• When the battery charge through the solar panel then LED ON gives green
light. When the battery charge through direct AC supply then the LED
• MAX232 device connected in µc as well as PC (Personal Computer).Give
the command from the PC and check the Output through LCD.
Block diagram Description
Power Supply Unit.
PIC16F877A microcontroller unit.
Power Supply Unit
• The ac voltage, typically 220V, is connected to a
transformer, which steps that ac voltage down to the
level of the desired dc output.
• A diode rectifier then provides a full-wave rectified
voltage that is initially filtered by a simple capacitor
filter to produce a dc voltage.
• This resulting dc voltage usually has some ripple or ac
The potential transformer will step down the power supply
voltage (0-230V) to (0-6V) level.
Then the secondary of the potential transformer will be
connected to the precision rectifier, which is constructed with
the help of op–amp.
The advantages of using precision rectifier are it will give peak
voltage output as DC; rest of the circuits will give only RMS
When four diodes are connected as shown in figure, the circuit
is called as bridge rectifier.
The input to the circuit is applied to the diagonally opposite
corners of the network, and the output is taken from the
remaining two corners.
Special Microcontroller Features
Flash Memory: 14.3 Kbytes (8192 words)
Data SRAM: 368 bytes
Data EEPROM: 256 bytes
Self-reprogrammable under software control
In-Circuit Serial Programming via two pins (5V)
Watchdog Timer with on-chip RC oscillator
Programmable code protection
Power-saving Sleep mode
Selectable oscillator options
In-Circuit Debug via two pins
Humidity is the presence of water in air. The amount of
water vapor in air can affect human comfort as well as
many manufacturing processes in industries.
The presence of water vapor also influences various
physical, chemical, and biological processes.
Humidity measurement in industries is critical because it
may affect the business cost of the product and the
health and safety of the personnel.
Hence, humidity sensing is very important, especially in
the control systems for industrial processes and human
The ULN2003 is a monolithic high voltage and high current
Darlington transistor arrays.
Applications include relay drivers, hammer drivers, lamp drivers,
display drivers (LED gas discharge), line drivers, and logic buffers.
The ULN2003 has a 2.7kW series base resistor for each Darlington
pair for operation directly with TTL or 5V CMOS devices.
* 500mA rated collector current (Single output)
* High-voltage outputs: 50V
* Inputs compatible with various types of logic.
* Relay driver application
• Temperature is the most-measured process variable in industrial
automation. Most commonly, a temperature sensor is used to convert
temperature value to an electrical value.
• Temperature Sensors are the key to read temperatures correctly and to
control temperature in industrials applications.
• In the temperature functional module we developed, we use the
LM34 series of temperature sensors.
• The LM34 series are precision integrated-circuit temperature sensors,
whose output voltage is linearly proportional to the Fahrenheit
• The LM34 does not require any external calibration or
trimming to provide typical accuracies of 1.2 F at room
temperature and 11.2 F over a full -50 to +300 F
• The LM34 is rated to operate over a -50 to +300 F
• The LM34 thus has an advantage over linear temperature
sensors calibrated in degrees Kelvin, as the user is not
required to subtract a large constant voltage from its output
to obtain convenient Fahrenheit scaling.
The MAX232 is a dual driver/receiver that includes a capacitive
voltage generator to supply RS 232 voltage levels from a single 5v
supply. Each receiver converts RS-232 to 5v TTL/CMOS levels.
Each driver converts TLL/CMOS input levels into EIA-232 levels.
The P3_0 (RX) and P3_1 (TX) pin of controller is connected to the
max 232 driver and the TX and RX pin of max 232 is connected to the
GSM modem or PC.
• A battery, which is actually an electric cell, is a device that
produces electricity from a chemical reaction.
• When the cell is connected to an external load, or device to be
• The negative electrode supplies a current of electrons that flow
through the load and are accepted by the positive electrode.
• When the external load is removed the reaction ceases.
PIC16F877A Microcontroller with Power Supply
PC with .net
• Embedded c
• MPLab Compiler or CCS Compiler
• Energy consuming.
• Load balancing and monetary expense
To Reduce the Power consumption
• This system can be applied in home and
industry section to reduce the power consume.
Further work is required for considering the effects of PV
output and electricity consumption forecast errors, and
vehicle-to-grid on the performance of the proposed
The EMS application is required to determine optimal EV charging
scheduling for smart homes/buildings with a PV system.
In this paper, a cost-effective EV charging method is proposed and
implemented for smart homes/buildings with a PV system.
The proposed smart EV charging algorithm for smart homes/buildings
consists of two stages: prediction of PV output and electricity
consumption, and EV charging scheduling.
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