1. A Project Report On
“DC GRID CHARGED WITH SOLAR ENERGY ”
Submitted for the Partial Fulfillment of
Requirements for the Award of Degree of
Bachelor of Engineering
Electrical Engineering
Department of Electrical Engineering
M.B.M. University, Jodhpur
3. INTRODUCTION
Sustainable, reliable, affordable, and clean energy systems have a
direct effect on the socio-economic development of any nation due
to increasing population, urbanization, and industrialization and at
the same time directly affect climate action (Sustainable
Development Goals (SDGs) 13) and other related SDGs objectives.
The developing countries rely on fossil fuels to meet energy
demand which pollutes the air, land, and water; causing
environmental degradation .It is necessary to explore renewable
energy resources to keep up with current energy demand and
maintain clean and sustainable environment .
4. Utilizing renewable energy sources will support the access to
affordable, reliable, and clean energy, reduce environmental and
health risks, diversify agricultural activities, generate additional
income and job opportunities, support innovation and sustainable
industrialization, benefitting local communities as well as national
and international sustainable development .
5. The efficient use of smart dc grid technology for photovoltaic
distributed generation and utilizing it in smart way, to build
infrastructure more reliable and to achieve the goal to cater the
need for tomorrow.
PV solar energy produces dc power and if used directly then power
loss will be minimized. Exact calculation of solar panels and proper
battery sizing leads to a reliable distributed generation system.
240Vdc grid will also help to minimize the power transmission
losses for up rise buildings, this will further enhance the system
efficiency. Proper selection of wire minimizes the electric
corrosion. Series and parallel combination of PV and battery cells
will enhance the use of suitable power supply for each electronic
device.
6. Other side where ac supply is required 240Vdc directly converts to
240Vac for Ac machines such as conventional appliances in order
to minimize transformer losses. This paper also presents an idea for
smart load shedding techniques and its practical implementation in
the form of smart dc Grid. Its various applications will enhance the
functionality of a smart Dc grid on residential load.
7. DC POWER GRID SYSTEM
A localized power system that can run independent of the main
power grid by generating and utilizing in DC power. The most
common ways of generating power for DC microgrids are with
solar panels, fuel cells, and wind turbines with any excess energy
stored in batteries. Conveniently, all these pieces of a DC microgrid
store or generate DC power making it immediately compatible with
computers, phones, LEDs, and most other end devices.
8. Parts of a DC grid:
Solar panel:
A solar panel /solar cell
panel/ solar electric panel/ photo-
voltaic (PV) module or solar
panel is an assembly of photo-
voltaic cells mounted in a
framework for installation.
Solar panels use sunlight as a source
of energy to generate direct
current electricity or photovoltaic
effect.
9. A collection of PV modules is
called a PV panel, and a
system of PV panels is called
an array. Arrays of
a photovoltaic
system supply solar
electricity to electrical
equipment.
10. PHOTOELECTRICEFFECT
The photovoltaic effect is a
process that
generates voltage or
electric current in
a photovoltaic cell when it is
exposed to sunlight. It is this
effect that makes solar panels
useful, as it is how the cells
within the panel convert
sunlight to electrical energy
11. Battery:
Batteries used for solar energy storage are available in two main types, lead-
acid and lithium-Ion. There are several other types available such as redox
flow batteries and sodium-ion but we will focus on the most common two.
Most modern energy storage systems use rechargeable lithium-ion batteries
and are available in many shapes and sizes .
12. USE OF IC LM7812 FOR VOLTAGE
REGULATION
LM7812 IC Features / Technical Specifications:
The Output current is 1.5 Ampere
Immediate short circuit shutdown function
Immediate over heat shutdown function
Low price
Authentic to use in commercial devices
Accurate and fixed 12V output
Maximum input voltage is 35V DC
Low standby current only 8mA
13. The IC provides fixed 12V output voltage no matter if the input
voltage is fluctuating or changing continuously or it is higher than
12V but the input voltage should not be more than 35V which is
the maximum input voltage limit this IC is capable to handle.
Moreover the input voltage should not be less than 14V that is the
minimum input voltage requirement of the IC to provide fixed 12V
output. Although this IC is designed for fixed output but the output
can also be adjusted if required by the user with the help of only
two external resistors at the output .
Applications:
Voltage step down circuits
12V Power Supplies
Motor Drivers
Battery Chargers
Solar Power Supplies
Microcontroller Related Applications
14. The schematic below shows a 12V
DC power supply circuit using 7812
IC.
The schematic below shows an
adjustable or variable power supply
using LM7812 IC with two external
resistors.
15. Other way of Regulation of voltage and current coming from the solar panel to the
battery
Solar charge controller
A solar charge controller is used to keep the battery from overcharging by
regulating the voltage and current coming from the solar panel to the battery. It
uses MPPT (maximum power point tracking is an electronic DC to DC converter
that optimizes the match between the solar array or PV panels, and the battery
bank or utility grid.)to accelerate solar charging of the battery up to 30% per
day.
WORKING:-A Solar Charge Controller works by regulating the voltage and
current flow from solar panels to a battery. It detects and monitors the battery
voltage, reducing the current when the battery is fully charged. The controller
maintains a float charge to keep the battery ready for use.
16. FLOAT BATTERY CHARGER
It is a a method of maintaining a cell or battery in a charged
condition by continuous, long-term, constant voltage charging at a
level sufficient to balance self-discharge.
17. WHY OVERCHARGING IS NOT DESIRABLE??:
A battery can quite simply die from being overcharged. This is the
safest side-effect, but not the only thing that can happen. An
overcharged battery will boil the sulfuric acid and distilled water
mix. The casing of the battery can become hot to the touch, and
begin to melt or swell.
If batteries are exposed to excessive temperature, they will stop
working, bulge, bubble, create sparks and flames, damage your
device, or blowup. Extreme heat can lead to battery corrosion that
shortens the average car battery life.
18. BLDC(Brushless DC) motor
As its name implies, brushless DC motors do not use brushes.
With brushed motors, the brushes deliver current through the
commutator into the coils on the rotor. It is not because the coils
are not located on the rotor. Instead, the rotor is a permanent
magnet; the coils do not rotate, but are instead fixed in place on
the stator. Because the coils do not move, there is no need for
brushes and a commutator.
19. The stator has a coil arrangement, as illustrated; The internal winding of the
rotor is illustrated in the Fig.3 (core of the rotor is hidden here). The rotor
has 3 coils, named A, B and C.
Out of these 3 coils, only one coil is illustrated in the Fig. :for simplicity.
By applying DC power to the coil, the coil will energize and become an
electromagnet.
As the rotor nears coil A, coil B is energized. As the rotor nears coil B,
coil C is energized. After that, coil A is energized with the opposite
polarity
this will make the rotor continuously rotate This process is repeated, and
the rotor continues to rotate.
20. The DC current required in the each coil is shown in the following
graph.
21. Advantages of BLDC motor:
One big advantage is efficiency, as these motors can control continuously at maximum rotational
force (torque). Brushed motors, in contrast, reach maximum torque at only certain points in the
rotation. For a brushed motor to deliver the same torque as a brushless model, it would need to use
larger magnets. This is why even small BLDC motors can deliver considerable power.
The second big advantage—related to the first—is controllability. BLDC motors can be controlled,
using feedback mechanisms, to delivery precisely the desired torque and rotation speed. Precision
control in turn reduces energy consumption and heat generation, and—in cases where motors are
battery powered—lengthens the battery life.
BLDC motors also offer high durability and low electric noise generation, thanks to the lack of
brushes. With brushed motors, the brushes and commutator wear down as a result of continuous
moving contact, and also produce sparks where contact is made. Electrical noise, in particular, is the
result of the strong sparks that tend to occur at the areas where the brushes pass over the gaps in
the commutator. This is why BLDC motors are often considered preferable in applications where it is
important to avoid electrical noise.
22. Applications of BLDC motor:
They are widely used in devices that run continuously. They have long been
used in washing machines, air conditioners, and other consumer electronics;
and more recently, they are appearing in fans, where their high efficiency has
contributed to a significant reduction in power consumption.
They are also being used to drive vacuum machines. In one case, a change in
the control program resulted in a large jump in rotational speed—an example
of the superlative controllability offered by these motors.
BLDC motors are also being used to spin hard disc drives, where their
durability keeps the drives operating dependably over the long term, while
their power efficiency contributes to energy reduction in an area where this is
becoming increasingly important.
23. SR.
No.
Apparatus Specificat
ion
Amount
(Rs.)
1 BLDC motor
10V,0.5A
400
2 solar panel
12V,10W
700
3 BLDC motor
controller
450
4 solar charge
controller
400
5 battery
12V,2200
mAh
900
6 switch 2A 10
7 wires 90
Total 2950
PROJECT WORK :
Object : To charge a 12V,1.3Ah battery with solar energy safely thereby using the battery to run a BLDC motor and other DC components if
required.
Apparatusrequired:
25. WORKING:-
When the solar panel comes in contact of the sunlight, it uses it as a source of energy
to generate DC supply.
•Solar charge controller regulated upto 12.5 volts , slightly higher than the battery
voltage to overcome the reverse supply and keeps it constant with uncertain output of
the solar panel.
•Output of the solar charge controller is used by the battery to be charged.When
battery becomes fully charged incase of not being used solar charge controller
reduces the voltage and maintains a float charge to keep the battery ready for use.
•Battery is connected to a switchboard which can be used for using DC supply.
COURTESY:-
•www.cleanenergyreviews.info
•www.technologystudent.com
•www.electrical4U.com
•Wikipedia
•www.amazon.com( for price estimation)
