Electric Vehicle Charging Method for SmartHomes/Buildings with a Photovoltaic System

Electric Vehicle Charging Method for SmartHomes/Buildings with a Photovoltaic System

Manjit Singh(U10EE719) Subash Kumar(U10EE026) Prabhat Ranjan(U10EE020)

Abstract

• 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 consumption.

• The implemented prototype application for home/building EMS can provide EV charging schedules according to user preferences

Introduction

• 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 electricity consumption.

• The implemented prototype application for home/building EMS can provide EV charging schedules according to user preferences.

Existing System

• There is no existing method is available for smart electrical vehicle charging.

• 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.

Proposed System• In this propose system, microcontroller is connected with

LCD, temperature sensor, Humidity sensor, solar panel and PC.

• 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 humidity sensor.

• 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.

BLOCK DIAGRAM:

Power Supply

PIC16F877AMicro

Controller

Driver Circuit

LCD

Temperature Sensor

Electrical Vehicle Battery

MAX 232

PC With .net

Solar panel

Humidity Sensor

Number of Units (Modules)

• Power supply unit• Microcontroller unit• Communication unit• Device driver unit• Display unit• Sensor 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

supply unit

Microcontroller unit

PIC microcontroller:

• In this project the Pic microcontroller is used in the Home section.

• 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

Communication unit

MAX232:

• 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

• Relay:

The relay is used to control the supply to the electrical device depend upon environment temperature.

Display unit

• LCD:

The LCD is used to display the information received in the Zigbee transceiver. The Temperature of the environment also displayed on LCD.

Sensor unit

• Temperature sensor:

The temperature sensor is used to monitor the surrounding temperature.

 • HUMIDITY SENSOR:

The humidity sensor is used to sense the environment humidity condition.

Given Input and Expected output

Power Supply Unit:

• In the power supply unit the 230V AC is converted into 5V DC.

Given Input:

• 230V AC supply is given as the input to the power supply unit.

Expected Output:

• The 5V DC supply is getting as the output from the power

supply unit.

Microcontroller UnitMicrocontroller Unit:

Microcontroller unit controls the devices connected with this (Max232, relay with the motor, and LCD).

PIC Microcontroller:

Given Input: 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 sensor value.

Expected Output: 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 system.

Communication Unit:

Communication Unit:

Communication devices send or receive the data’s in wire/wireless to the other section.

MAX232:• 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.

 • Expected Output:

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.

Display UnitLCD is used as the display unit in this project.

LCD:

Given Input:

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 microcontroller.

The commands and datas will be given as the hexadecimal format from the

microcontroller.

Expected Output:

The data from the command lines will initialize the LCD. The data from the data

lines will be displayed in the LCD.

Relay Unit

Relay and battery

In this project the battery is load and which is connected with the relay unit.

Given Input: 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 purpose. It contains two terminals, they are normally open, normally closed.

Expected Output: 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 supply.

Circuit Diagram

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

respectively.• 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

solar panel.• 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 OFF.• 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

• Block 1: Power Supply Unit.•  • Block 2: PIC16F877A microcontroller unit.•  • Block 3: Humidity sensor.•  • Block 4: Relay driver.•  • Block 5: Temperature sensor.•  • Block6: Max 232.•  • Block7: Battery•  • Block 8: LCD.

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

voltage variation.

Power Supply Unit

Working principle

Transformer 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 output.

Bridge rectifier 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.

PIC16F877A Microcontroller

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

PIC 16F877A

• .

Humidity sensor

  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 comfort.

Relay driverDriver circuit: 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.

FEATURES

* 500mA rated collector current (Single output)

* High-voltage outputs: 50V

* Inputs compatible with various types of logic.

* Relay driver application

Relay driver

Temperature sensor

• 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 temperature.

Temperature sensor

• 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 temperature range.

• The LM34 is rated to operate over a -50° to +300°F temperature range.

• 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.

LCD:

Max 232• 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.

Max 232

Battery Battery • 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

powered.• 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.

Hardware Requirements

• PIC16F877A Microcontroller with Power Supply• Temperature sensor• Humidity sensor • Max 232• LCD• Battery • Solar panel• PC with .net

Software Requirements:• Embedded c• MPLab Compiler or CCS Compiler• .net

Advantages:• Energy consuming.• Load balancing and monetary expense reduction.

 Applications:

To Reduce the Power consumption• This system can be applied in home and

industry section to reduce the power consume.

Future Enhancement:

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 method.

Conclusion: 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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