Design and development of a pure sine wave inverter: A safe supply for digital networks.

Project Title

Design and development of a pure sine wave inverter: A safe supply for digital networks.

Project Area of Specialization Electrical/Electronic EngineeringProject Summary

DC to AC power inverters, which aim to efficiently  transform a DC power source to a high voltage AC source, similar to power that would be available at an electrical wall outlet. Inverters are used for many applications, as in  situations where low voltage DC sources such as  batteries, solar panels or fuel cells must be converted so that devices can run off of AC power.  One example of such a situation would be converting electrical power from a car battery to run a laptop, TV or cell phone. The method in which the low voltage DC power is  inverted, is completed in two steps.  The first being the conversion of the low voltage DC power to a high voltage DC source, and the second step being the conversion of the high DC source to an AC waveform using pulse width modulation.  Another method to complete the desired outcome would be to  first convert the low voltage DC power to AC, and then use a transformer to boost the voltage to 120  volts. This project focused on the first method described and specifically the transformation of a high voltage DC source into an AC output. Of the different DC/AC inverters on the market today  there are essentially two different forms of AC output generated: modified sine wave, and pure sine wave 1 .  A modified sine wave can be seen as more of a square wave than a sine wave; it passes the high DC voltage for specified amounts of time so that the average power and rms voltage are the same as if it  were a sine wave.  These types of inverters are much cheaper than pure sine wave inverters and therefore are attractive alternatives. Pure sine wave inverters, on the other hand, produce a sine wave output identical to the power coming out of an electrical outlet.  These devices are able to run  more sensitive devices that a modified sine wave may cause damage to such as: laser printers, laptop computers, power tools, digital clocks and medical equipment.  This form of AC power also reduces audible noise in devices such as fluorescent lights and runs  inductive loads, like motors, faster and quieter due to  the low harmonic distortion.

Project Objectives

To produce a pure sine wave DC-AC inverter that would output at 50Hz, 110 volts RMS with 220 volts Output, would be cheap to manufacture, and fairly efficient in the method in which it produces it.

Project Implementation Method

Our most electronic devices used in power sector , medical sector and other sectors, and home appliances, are designed to function on sinusoidal AC waveforms, yet the inverters in the market are not pure sine wave and they do not have proper cutoff charging and discharging circuit , so our main goal will be to make a pure sine wave inverter, according to the international standard which states the battery should not be discharged not less than 15% and charged not more than 80%, for attaining long life of battery . We will design such a filters, which will cater the problem of sharp edges in the waveform, by smoothing them. Our designed circuit will when the battery health will at 15% so that the battery health can be increased. The major problem in the inverters available in the market, is that of power loss, so our main aim will be to decrease the power loss to minimum

Benefits of the Project

In the market of power inverters, there are many choices. They range from the very expensive to the very inexpensive, with varying degrees of quality, efficiency, and power output capability along the way. High quality combined with high efficiency exists, though it is often at a high monetary cost. The high end pure sine wave inverters tend to incorporate very expensive, high power capable digital components. The modified sine wave units can be very efficient, as there is not much processing being performed on the output waveform, but this results in a waveform with a high number of harmonics, which can affect sensitive equipment such as medical monitors. Many of the very cheap devices output a square wave, perhaps a slightly modified square wave, with the proper RMS voltage, and close to the right frequency.

Technical Details of Final Deliverable

Filter Designing: Complexity in Filter designing is much higher as it require deep analysis and calculations. Sine wave : Attaining a pure sine wave is the most important and difficult task of our inverter this is a complex task to achieve. CUT-OFF CIRCUIT: Inverter are long term investment either done in home or industry.one of the main goal of our inverter is that it should ensure long life of battery by efficiently taking care and monitoring of charging and discharging f battery. Cost Effectiveness: The pure sine wave inverters available in the market are costing much higher than the modified sine wave inverters, so maintaining the cost in the effective bracket will be our another challenge while making this project.

Final Deliverable of the Project Hardware SystemCore Industry Energy Other Industries Others Core Technology OthersOther Technologies Clean TechSustainable Development Goals Affordable and Clean Energy, Industry, Innovation and Infrastructure, Sustainable Cities and Communities, Responsible Consumption and ProductionRequired Resources

Item Name	Type	No. of Units	Per Unit Cost (in Rs)	Total (in Rs)
			Total in (Rs)	64000
Battery	Equipment	1	25000	25000
Inverter body	Equipment	1	5000	5000
Components ( resistor ,capacitor ,transistor, MOSFET etc.	Equipment	1	5000	5000
Transformers	Equipment	1	10000	10000
Pcb board	Equipment	1	8000	8000
Microcontroller dspic30f2010	Equipment	1	6000	6000
Others	Miscellaneous	1	5000	5000