Construction of Inverter with Power Factor Improvement

Transcription

1 Construction of Inverter with Power Factor Improvement 1 AkashJadhav, BE-E&Tc, VIIT, Pune 2 AdityaBahirat, BE-E&Tc, VIIT, Pune 3 HimanshuBhadane, BE-E&Tc, VIIT, Pune Abstract: The need of power backup is very essential in industries and day to day life. This project is involves the design and construction of a DC to AC inverter system. When the power from the grid is gone off or power cut from the grid then we have to need the solution. So inverter is the best option in this situation. The conversion of 12V DC to the 220V AC is the objective behind project.determining the power factor of the load and improve the power factor so that the efficiency of the system will be improved and the loads will work on most efficient way. The DC supply from battery will be converted into AC supply and it gets connected to the load and then the load is connected to the power factor correction circuit. The PIC microcontroller is used in the power factor circuit. It will measure the phase difference and improve the power factor by adding accurate capacitor in parallel with load. Keywords: Inverter, Powerfactor,Battery 261

2 1.INTRODUCTION Inverter is device which changes direct current into alternating current. Inverter does not produce power by its own, we have to provide the power by the direct source.we are going to convert 12V DC to 220V AC. The load which are generally connected to the AC source are inductive and capacitive loads. Inductive loads have lagging power factor and capacitive loads have leading power factor. Power factor is the ratio of working power to the total power.many industries pays huge amount bill on penalties due to power factor. So to improve power factor there are many methods available such as phase shifting,capacitor bank, synchronous condenser. Due to installing these system to the industry or home we can get rid of the extra penalties and the efficiency of the system is going to be improved. The improving power factor of the circuit will lead to the efficient output. 262

3 2. MOTIVATION Power Inverters and their use have received more and more interest in the previous years. This is because it provides wide range of applications. A system consisting of this capability provides: 2.1 Power cutoff: In the case of cities and towns, mostly in village area the power cutting is often problem.to overcome this situation and do day to day chores the inverters are use.most of the inverters are not so cost effective they are not affordable by poor people so to do daily household and other work the cost effective inverter should be made. 2.2 Power Factor: Power factor is very important topic in power systems. With the power factor corrections, current is reduced with same power consumes. Thus the efficiency of power transmission improved. With the correction of power factor the reactive power decreases and the real power is maximum which could be delivered to consumer 3.OBJECTIVES 3.1 To construct an inverter with low voltage DC source to operate AC mains equipment with the higher wattage. 3.2 To reduce the size or to compact as well as reduction in cost of an inverter. 3.3 smooth functioning of the equipment s output of inverter needs to be in sine wave. 3.4 To increase the efficiency of inverter. 3.5 Increasing the power factor up to unity so as to efficient utilization of power, which is most crucial factor in the transmission line. 263

4 fig.1:block diagram of circuit 264

5 4.METHDOLOGY 4.1. Switches: There are different types of power switches power diodes,thyristors,power BJTs,Power MOSFETs,IGBTS and SIT. For an inverter MOSFET and IGBTS are mostly used power MOSFET. They can operate at higher frequencies but usually limited to power ratings severally 1000v and 50A. IGBT are the voltage control power transistors it also offers better switching than MOSFET. According to our requirement MOSFET is chosen. The power diode is use as afreewheeling diode. 4.2 SPWM Method: The voltage supply electrical inverter that uses the PWM switch method have a DC input voltage (VDC = VS) that's sometimes constant in magnitude. The electrical inverter sjob is to aquire the DC input and to provide AC output, whereverthe magnitude and frequency may be controlled.there are many techniques of Pulse width Modulation (PWM).Inthis style the sinusoidal Pulse Modulation (SPWM) technique has been used for managing the electrical inverter because it may be directly controlled the electrical inverter output voltage and output frequency as per the sine functions. SPWM is mostly used method. Fig: 2Components of SPWM signal generated by analog signal 265

6 Wien Bridge: We are going to make inverter using analog control circuit. The essential part of the circuit is sine wave oscillator. Wien bridge oscillator can also generate sine wave. Also along with this we can also use AD639 it is a functional converter which provides all standard trigonometric function Phase Shifter: the output of wien bridge oscillator is connrcted by phase shifter to geneate phase difference and 2 phase shifter to generate 2400 phase differnce Comparator: The reference sine wave is compared by three 301 comparators. Inverting amplifier: Two inverting electronic equipment is employed at the output of comparator circuit to invert the switch signals 266

7 Fig.3 Power Factor Improvement 1. AC Source: AC Source genarate AC current.alternating Current is a variant of electrical current, in which the direction of the flow of electrons flow continuouslyat regular intervals 2. Current Sensor: A current detector is a device that detects electrical current, and produces signal proportional to it.the produced signal may be analog or may be digital output. 3. Voltage sensor: A voltage detector is a device that detects electric voltage, and produces a signal proportional to it. The produced signal may be analog ormay be digital output. 4. Zero Crossing Detector: A zero crossing detector is form of voltage comparator, used to detect a sine waveform transition from positive and negative that coincides when the i/p crosses the zero voltage condition. 5. PIC18F4520: Peripheral interface controller (PIC).It is central processing unit of system. It monitors the time and take corresponding action. It is interfaced to LCD. 6. LCD : LCDis employed in an exceedingly project to check the output of the application. We have used 16x2 LCD.LCD plays an important role in project to see the output. 267

8 Fig.4Voltage zero crossing detection simulation result Fig.5Current zero crossing detection simulation result Acknowledgements I am very thankful to our guide, Prof R.S.SONAGIand evaluators Prof. for great guidance and support. I am thankful to HOD Prof. S.V.Kulkarni and faculty members of E&TC department of VIIT, Pune. REFERENCES: 268

9 [1] Ned Mohan, Tore M. Undeland, William P. Robbins, Power Electronics: Converters, Applications, and Design, John Wiley & Sons, Inc. (Book) [2] Muhammad H. Rashid, Power electronics: circuits, devices, and applications, 3rd ed. 2004, Pearson/Prentice Hall. (Book) [3] P.C. Sen, Power Electronics, Tata Mcgraw-hill, India. (Book) [4] Bose, B.K., 2002, Modern Power Electronics and AC Drives, Prentice Hall PTR, New Jersey. (Book) 269