A Solar Inverter

Introduction A Solar Inverter  The main aim of this project 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.

A Solar Inverter Project Block Diagram

A Solar Inverter Solar inverters may be classified into three broad types  Stand-alone inverters  Grid-tie inverters  Battery backup inverters

A Solar Inverter Stand-Alone Inverters  It is used in isolated systems.  The inverter draws its DC energy from batteries charged by photovoltaic arrays.  Many stand-alone inverters also incorporate integral battery chargers to replenish the battery from an AC source.  Normally these do not interface in any way with the utility grid.  It does not required to have anti-islanding protection.

A Solar Inverter Grid-Tie Inverters  It match phase with a utility-supplied sine wave.  Grid-tie inverters are designed to shut down automatically upon loss of utility supply.  They do not provide backup power during utility outages.  Grid tie inverter converts DC power produced by PV array to AC power.

A Solar Inverter Battery Backup Inverters  These are special inverters which are designed to draw energy from a battery.  It manage the battery charge via an on board charger, and export excess energy to the utility grid.  These inverters are capable of supplying AC energy to selected loads during a utility outage  The battery backup inverters are also required to be installed with an anti- islanding protection.

A Solar Inverter Hardware Requirements  Bridge-MOSFETs drive  Step up Transformer  Voltage regulator  MOSFET driver  PWM inverter IC  Solar Panel  Battery

A Solar Inverter Battery  An electrical battery is a combination of one or more electrochemical cells, used to convert stored chemical energy into electrical energy.  The battery has become a common power source for many household, robotics and industrial applications.  Larger batteries provide standby power for telephone exchanges or computer data centers.

A Solar Inverter PWM Inverter IC  The PWM Inverter is used to develop the PWM pulses based on a fixed frequency using common oscillator.  The IC SG3524 operates at a fixed frequency, the oscillation frequency is determined by one timing resistor RT and one timing capacitor CT.  The SG3524 contains an inbuilt 5V regulator that supplies as a reference voltage, also providing the SG3524 internal regulator control circuitry.

A Solar Inverter PWM Inverter IC  Comparator provides a linear control of the output pulse width (duration) by the error amplifier.  The resultant PWM pulse from the comparator is passed to the corresponding output pass transistor (Q1, Q2 refer block diagram) using the pulse steering flip flop, which is synchronously toggled by the oscillator output.

A Solar Inverter Inverter IC Block Diagram

A Solar Inverter MOSFET(IRF 510)  The metal–oxide–semiconductor field-effect transistor (MOSFET, MOS- FET, or MOS FET) is a device used for amplifying or switching electronic signals.  The basic principle of the device a voltage on the oxide-insulated gate electrode can induce a conducting channel between the two other contacts called source and drain.  It is by far the most common transistor in both digital and analog circuits, though the bipolar junction transistor was at one time much more common.

A Solar Inverter BC547 (NPN –Transistor)  The BC547 transistor is an NPN Epitaxial Silicon Transistor.  It is used in general-purpose switching and amplification BC847/BC547 series 45 V, 100 mA NPN general-purpose transistors.  The ratio of two currents (Ic/Ib) is called the DC Current Gain of the device and is given the symbol of hfe or nowadays Beta, (β).

A Solar Inverter BC547 (NPN –Transistor)  The current gain from the emitter to the collector terminal, Ic/Ie, is called Alpha, (α), and is a function of the transistor itself

A Solar Inverter Solar Panel  Solar panel refers to a panel designed to absorb the sun's rays as a source of energy for generating electricity.  Solar Panel is an array of Several solar cells (Photovoltaic cells). Solar Panel  The arrays can be formed by connecting them in parallel or series connection depending upon the energy required.

A Solar Inverter Working of Solar Panel and Inverter  Expose the cell to light, and the energy from each photon (light particle) hitting the silicon, will liberate an electron and a corresponding hole.  If this happens within range of the electric field’s influence, the electrons will be sent to the N side and the holes to the P one, resulting in yet further disruption of electrical neutrality.  This flow of electrons is a current; the electrical field in the cell causes a voltage and the product of these two is power.  The solar energy is stored in the battery from Photo-Voltaic cells.

A Solar Inverter Working of Solar Panel and Inverter  This stored energy of the battery is converted to AC supply of 50Hz frequency using PWM inverter IC with MOSFET gate driver IC to the driver MOSFET bridge and step-up the voltage by a transformer.

A Solar Inverter Needs Of Solar Power  Electricity rate has hiked in last four years.  We need to focus on alternate option because of environmental concerns.  It has several advantages over other forms of electricity generation.

A Solar Inverter About The Inverter  This energy generated by the panel, in the form of direct current (DC), is transmitted to the inverter. The job of the inverter is to convert the DC power the solar panel has generated to alternating current (AC) that is transmitted on the grid. The inverter converts DC to AC by using two switches which convert the positive only DC power to an alternating positive to negative AC power.  The inverter will then step up the voltage from 12 volts to 120volts, which is the voltage used throughout the US electrical grid. This conversion of voltage is what allows a 12 volt DC solar polar to be tied into a 120 volt AC grid.

A Solar Inverter Advantage  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.

A Solar Inverter Disadvantage  Cental 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.  Micro inverters are more expensive.

A Solar Inverter Applications  Can use Solar Inverter for domestic application.Solar Inverter  It can be plugs in your house for your TV, computer, and other wired products.  Can use Solar Power Inverters For Industrial Application.

A Solar Inverter Conclusion  Inverters are usually about 95% efficient. Inverters play a significant role in providing alternate current supplies at the times of crucial power requirements. The primary use of solar inverters is to convert direct current to alternating current through an electrical switching process.