Modeling and analysis standalone PV systems

  Project Objectives (less than 2500 characters)

Project Title

Project Area of Specialization

Electrical/Electronic Engineering

Project Summary

The global trend of the 21st century is shifting towards renewable energy for meeting our
electricity demands. Most of the increase in electricity production from renewables has come
from solar, wind and hydro-power. Shifting towards this trend was not a big deal for
developed countries like America, Germany, England etc., but inclination towards solar
electricity is a great matter of concern for under-developed and developing countries of the
world. For them a solution here which is extracted from the industries' stand-alone PV
systems is "Micro-grid”. Micro-grid is developed when a small group of houses i.e. 3-6
houses develop their own stand-alone PV system. In this way, they will not suffer electricity
shortage and also they will have economical benefits. The proposed system will also address
the problem of depletion of conventional energy, global warming and poor health problems
mainly lung and skin cancers.
The proposed microgrid system will have minimum possible number of houses having
their own PV modules installed on their roof tops or free space for easy maintenance. The
system will also comprise of a centralized back-up battery bank and centralized generator.
The energy sharing strategy in the houses will be enabled through a centralized controller
which will not let the surplus energy go to waste. The decentralized battery, DC-DC boost
converter and DC-AC inverter will also contribute for each individual house

Project Objectives

1. To design and model solar PV system in MATLAB/Simulink that can supply
electricity to various load centers.
2. To design centralized control system which will control energy sharing in the system.
3. To supply energy into the system from stand-by unit

Project Implementation Method

Design Methodology:

Figure 1: Block Diagram of Proposed System
In proposed micro-grid, each house will have its own solar panel, battery bank, DC-DC
boost converter and DC-AC converter (inverter). Each house will connect to the micro-grid
through its own main switch which allow it to enter or leave the system at any time. The
centralized battery bank and generator are the backups for the entire system.
The system will work as follows:
STEP 1: The solar panel of each house will generate electricity.
STEP 2: The generated electricity will serve the loads by boosting-up the DC
voltage and then converting it into AC. If there is excess energy, then battery will
be charged.
STEP 3: After battery is charged and house’s loads are served and there is still
excess energy, then controller will check for the need of other houses, if they
need surplus energy, then they will be served. If other houses do not need, then
this excess PV energy will charge the centralized battery bank for backup.
STEP 4: The system will also have a centralized generator which will use petrol
as fuel

Design Methodology:

Benefits of the Project

In elite and some remote residential areas of Pakistan, where individual houses have
developed their own stand-alone PV Systems, most of the PV energy goes waste when the
battery bank is fully charged and PV system produces more power than the load demand. In
such areas of Pakistan, no strategy exists among the houses to share excess energy with each
other to optimize the usage of PV energy. On the other hand, in such stand-alone systems,
battery bank usually suffers from deep discharging and over charging effects i.e. batteries
lose their charge storing capacity and unwanted gases are produced inside the batteries which
reduce their life time. As a result, batteries need to be replaced before their expected life
time, which leads to higher capital cost of stand-alone systems. The focus of recent research
is all on excess energy sharing to the grid for earning money, whereas off-grid systems have
become obsolete. Many houses having solar energy systems in case of contradiction cannot
isolate themselves from the micro-grid because of the interconnected PV systems

Technical Details of Final Deliverable

1: The solar panel of each house will generate electricity.

2: The generated electricity will serve the loads by boosting-up the DC
voltage and then converting it into AC. If there is excess energy, then battery will
be charged.

3: After battery is charged and house’s loads are served and there is still
excess energy, then controller will check for the need of other houses, if they
need surplus energy, then they will be served. If other houses do not need, then
this excess PV energy will charge the centralized battery bank for backup.

4: The system will also have a centralized generator which will use petrol
as fuel.

1: The solar panel of each house will generate electricity.

2: The generated electricity will serve the loads by boosting-up the DC
voltage and then converting it into AC. If there is excess energy, then battery will
be charged.

4: The system will also have a centralized generator which will use petrol
as fuel.