A Prototype Of Solar Powered Car Guided by: Mr. M. Sriramulu Presented by: Sophiya Senapati(110101eer075) Baisakhi Samal(110101eer027) Subhasmita Patra(110101eer040) G.Hari Prasad(110101eer50) Deepankar Samantsinghar(110101eer46) INTRODUCTION • The basic principle of solar car is to use energy that is stored in a battery during and after charging it from a solar panel. • The charged batteries are used to drive the motor which serves here as an engine and moves the vehicle in reverse or forward direction. • The DPDT switch and relay is provided to control the motor speed. • This avoids excess flow of current when the vehicle is supposed to be stopped suddenly. DESCRIPTION • Energy from Sun is captured by the solar panels and is converted to electrical energy. • The electrical energy thus formed is being fed to the batteries that get charged and is used to run 12V high torques DC series motor. • The shaft of the motor is connected to the rear wheel of the vehicle through Belt Drive. • The batteries are initially fully charged and thereafter they are charged by panels. • This helps in completing the charging-discharging cycle of the batteries, which is very important for proper working of batteries. DIFFERENT PARTS 1 front & 2 rear wheel Plywood as a base DC series motor Solar panel Charge Controller Battery Relay DPDT switch SPECIFICATIONS • 4 Batteries each of 4V & 1.5A, connected in series. • 2 Solar Panel each of 8.86V & 0.35A are connected in series. • Speed is approximate 1km/hr . • 2 Motor each of 60rpm and 12V. • 2 DPDT swtich • 4 relay each of 12V • Charging time max 4-5hrs depending on light and heat intensity of weather. • Discharging time is 3-4hrs maximum. DC MOTOR • Permanent magnet brushless DC series motor. • It has a very high efficiency characteristics over a large power range. • Require minimal maintenance, due to elimination of mechanical commutator and brushes. • Long operating life and higher reliability. • No brushes means no arcing which can be paramount when working in flammable gas locations. • Capable of producing very high torque at a low power. • High power density and torque to inertia ratio give a fast dynamic response. Continue… • Speed restrictions due to the traditional mechanical commutator are eliminated. • 2 DC motor each of 12v is used. These are connected to the 2 rear wheel of the solar car prototype. • Wheels are connected to the shaft of the motor through Belt Drive. • 4 L-shaped clamp is used for support purpose on the base. BATTERY • The primary energy source for the vehicle is the battery. • The overall battery voltage is chosen depending on the motor’s specification and the desired nominal cruising speed. • lead-acid batteries is used due to ease of availability and relatively cheap cost. • One major drawback is- relatively large weight. • In this prototype, 4 lead acid batteries are connected in series, each of 4v and 1.5A . So total voltage is 12v. SOLAR PANEL • Absorbs energy from sun. • Energy obtained from the sun by a solar array supplement the energy taken from the batteries. • The solar array can sometimes supply ample energy, and the excess simply flows into the batteries. • The solar array consists of a configuration of solar photovoltaic cells, usually encapsulated to protect against the elements and damage. • The encapsulation of cells also increases the overall efficiency of the array. Continue… • Solar cell type is mono-crystalline cells having an efficiency of nearly equal to 15% . • Solar cells convert sunlight (photons) to electricity (electrons). • Ratings of the panel is 3watt, 8.86V, 0.35A, open circuit voltage is 10.72V and 0.38A. • Here 2 solar panels are connected in series and total voltage is around 17V. CHARGE CONTROLLER • A solar charge controller regulates the voltage and current coming from your solar panels which is placed between a solar panel and a battery. • It is used to maintain the proper charging voltage on the batteries. • As the input voltage from the solar panel rises, the charge controller regulates the charge to the batteries preventing any over charging. • The charge controller circuit is consisting of diode, capacitor and one LED light is connected through a resistance. • Diode is used to prevent the reverse flow of current from battery to solar panel. MOTOR CONTROLLER • In order to control the motor DPDT switch and relay are used. • Here 4 relays and 2 DPDT switch are used. • One DPDT switch is connected with two relays and these relays together connected to a single motor. Block Diagram Solar panel Charge controller Battery Motor controller Motor DPDT switch • It has 6 terminal. • The middle points of this is connected to VCC and ground. • Other 4 points are connected with motor. RELAY • It has 5 terminal. • One common terminal,2 database terminal (D1 & D2) and normally open and normally closed switch. • Between D1 and D2 one coil is there and it acts like a magnet. • At first the relay is normally closed after power given to the coil it is normally opened. Continue… • It is used for braking purpose. • Ratings of relay used • NO-7A 250V ac 12A 120V dc NC-10A 120V ac 10A 24V dc CALCULATION • For a prototype model, we have taken a motor of 12V & 60 rpm. P=V*I= where, I= (measured by multimeter) T= Power*speed = • Since the motor is 12V, We required a battery of 12 V so as to give power to the motor . • Battery used is 4V,1.5Ah,Battery connected in series so Total voltage=12V Total current=1.5A Now, Charging current= 10% of battery current = 10% * 1.5= 0.15Ah Since, Solar Panel rating must be greater than that of battery ratings. Voltage of solar panel > 12v current > charging current i.e. 0.15 So ratings of the solar panel is: 2 solar panel each of 8.86v and 0.35A. so, voltage of solar panel= 17.72v≈18v • In ideal case, Charging current= (battery current)/(current of solar panel) = 1.5/0.35=4.28hr • In practical, Charging current= (1.5)+(12% of 1.5)/0.35 & Discharging current= (1.5)-(12% of 1.5)/0.35 rating Cost Analysis • • • • • • • • • • • 2 solar panel -1000 2 motor -400 Tyre with belt drive-250*2=500 Base plywood-100 Castro wheel-50 Wire for connection-15*4=60 Battery-70*4=280 Relay-20*4=80 DPDT-25*2=50 Switch Box- 50 L clamp-20*4=80