A Seminar ReportOn

Implementation of Solar Inverter for

Home, Garden, Street Light Applications

Our aim is to use solar energy for household loads using an inverter. Solar energy is converted to electrical energy by photo-voltaic(PV) cells. This energy is stored in batteries during day time for the utilization purpose whenever required.

A solar inverter, or PV inverter, converts the direct current (DC) output of a photovoltaic solar panel into a utility frequency alternating current (AC) that can be fed into a commercial electrical grid or used by a local, off-line electrical network.

INTRODUCTION

PROJECT BLOCK DIAGRAM

CLASSIFICATION OF SOLAR SYSTEM

Stand-alone system (off-grid system)

Grid-tie system (on-grid system)

STAND-ALONE SYSTEM

Stand-alone PV systems are designed to operate independent of the electric utility grid, and are generally designed and sized to supply certain DC and/or AC electrical loads.

The inverter draws its DC energy from batteries charged by photovoltaic arrays.

Normally these do not interface in any way with the utility grid.

STAND ALONE SYSTEM COMPONENTS

GRID-TIE SYSTEM Grid-tie inverters convert DC electrical power into AC power

suitable for injecting into the electric utility company grid.

Grid Tie System is the simplest and most cost effective way to connect PV modules to regular utility power.

Grid-Connected systems can supply solar power to your home and use utility power as a backup.

If your system is generating more power than you are using, the excess will flow back into the grid, turning your meter backwards.

GRID TIE SYSTEM COMPONENTS

HARDWARE REQUIREMENTS

Step up Transformer

MOSFET

PWM Inverter

Solar Panel

Battery

PIC16f877

SOLAR PANEL

Solar panel refers to a panel designed to absorb the sun's rays as a source of energy for generating electricity.

Expose the cell to light, and the energy from each photon (light particle) hitting the silicon, will liberate an electron and a corresponding hole.

This flow of electrons is a current; the electrical field in the cell causes a voltage and the product of these two is power

Solar panel is an array of Several solar cells (Photovoltaic cells).

ABOUT THE INVERTER

The energy generated by the solar panel, in the form of direct current (DC), is transmitted to the inverter. The job of the inverter is to convert the DC power to alternating current (AC) that is transmitted on the grid.

The transformer will then step up the voltage from 12 volts to 230volts, which is the voltage used throughout the Indian electrical grid. This conversion of voltage is what allows a 12 volt DC solar panel to be tied into a 230 volt AC grid.

PWM INVERTER

Pulse Width Modulation or PWM technology is used in Inverters to give a steady output voltage of 230 or 110 V AC irrespective of the load.

The Inverters based on the PWM technology are more superior to the conventional inverters.

The use of MOSFETs in the output stage and the PWM technology makes these inverters ideal for all types of loads.

ADVANTAGE OF PULSE WIDTH MODULATION

In a standard Inverter without the PWM technology, the output voltage changes according to the power consumption of the load. The PWM technology corrects the output voltage according to the value of the load by changing the Width of the switching frequency in the oscillator section.

As a result of this, the AC voltage from the Inverter changes depending on the width of the switching pulse. To achieve this effect, the PWM Inverter has a PWM controller IC which takes a part of output through a feedback loop.

The PWM controller in the Inverter will makes corrections in the pulse width of the switching pulse based on the feedback voltage.

This will cancel the changes in the output voltage and the Inverter will give a steady output voltage irrespective of the load characteristics.

PIC 16F877

PIC 16F877 is one of the most advanced microcontroller from Microchip. This controller is widely used for experimental and modern applications because of its low price, wide range of applications, high quality, and ease of availability.

It is ideal for applications such as machine control applications, measurement devices, study purpose, and so on.  

The PIC 16F877 features all the components which modern microcontrollers normally have. 

Inverter String

inverterCenter inverter

TYPE OF SOLAR INVERTER

STRING INVERTERS

CENTER INVERTER

WHAT IS MPPT ?

It is an electronic system that operates the photovoltaic modules in a manner to extract the maximum power from the system. What is maximum power point ? It is a operating point at which maximum power can be

extracted from the system. Usually represented as MPP.

The output of solar module is a function of solar irradiance, temperature.

Generally MPPT is installed in between PV system and inverter Coupling to the load for maximum power transfer may required either providing a higher voltage at lower current or lower voltage at higher current.

APPLICATIONS

Can use solar inverter for domestic application.

It can be plugs in your house for your TV, computer, and other wired products.

Can use Solar Power Inverters For Industrial Application.

ADVANTAGES

High efficiency and outstanding energy harvest in a small modular design.

Ease of installation to save time and money.

Is compatible with other GT Series models to customize the inverters to the array.

Central and micro inverters can be up to 95% efficient.

DISADVANTAGES

Central inverters is difficult to do properly and is usually the hardest part of designing a solar array.

For central inverter, the output from your whole array can drop significantly, if any one of the panel is shaded.

Another weakness of a central inverter is that you won’t be able to monitor how each individual panel is performing.

ANY QUERIES?

THANK YOU