analysis of shunt apf (active powerfilter)
DESCRIPTION
An Analysis of Shunt ACtive Power Filter Based on Instantaneous Reactive Power TheoryTRANSCRIPT
AN ANALYSIS OF SHUNT ACTIVE POWER FILTER BASED ON INSTANTANEOUS
REACTIVE POWER THEORY
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Batch Members
A. Saroja Padma vathi (09MN1A0203)D. Rajesh (09MN1A0213)S. Jakeer Hussain (09MN1A0239)K. Tarakeswara Rao (10MN5A0202)
Project Guide
P. Taviti Naidu sirAsst. Prof. Dept. of EEE
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ABSTRACT
Shunt Active Power Filter is an ideal device that could manage the harmonic compensation in an adjustable and dynamic manner. This article reviews the basic principle of shunt active power filter, along with the current tracking circuit based on the instantaneous reactive power theory and the main circuit performing as an inverter with PWM hysteresis control. A comprehensive control method is analyzed and a harmonic compensation simulation is conducted, the result of which verifies the harmonic detection algorithm is well-proposed and the power quality of the grid is overall-enhanced.
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INTRODUCTION
Harmonic suppression and reactive power Compensation are essential for the construction of smart grid, which gathers, distributes, and acts on the behavior of suppliers and consumers in order to improve the efficiency and sustainability of electric services. With the increasingly widespread application of power electronic device, such as electronic appliances, switching model power supplies and electronic ballasts, the harmonic contamination they produce in grid has given rise to a variety of safety concerns.
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EXISTING METHODS TO ELIMINATE HARMONICS
By increasing the pulse number
Passive Filters
Active Filters
Notching & Noise
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ADVANTAGES
Response is high
Active filter is capable of handling harmonics ranging between fluctuating frequencies
It can be operated at lower order harmonic
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DISADVANTAGES
Whenever our load changes, the filter value also changes.
It can not provide flexible compensation
It causes resonance problems
Needs cooling system
Not suitable for higher order harmonics
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SHUNT ACTIVE POWER FILTER
Along with increasing demand on improving quality, the most popular technique that has been used is active power filter (APF); this is because APF can easily eliminate unwanted harmonics, improve power factor and overcome voltage sags.
It is a combination of inverter and capacitor.
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BLOCK DIAGRAM
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REFERENCE CURRENT CALCULATION
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CURRENT CONTROL CIRCUIT
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MAIN CIRCUIT PARAMETER DESIGN
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MAIN CIRCUIT WORKING
The working mode of the main circuit is determined by the condition of its six switches. Generally speaking, there is always a single device switched on in all three groups (S1/S4, S3/S6 or S2/S5), constructing six different combinations all together.
Ka is 1/3 when lower bridge arm is working.Ka is -2/3 when upper bridge arm is working.
SSITMATLAB/SIMULINK MODELING OF NON-LINEAR LOAD
WITHOUT APF
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WAVEFORMS OF LOAD CURRENT AND POWER FACTOR
Load current Waveforms before connecting the APF to the distribution line
Power factor Waveforms before connecting the APF to the distribution line
SSITMATLAB/SIMULINK MODELING OF NON-LINEAR LOAD WITH APF USING BUTTERWORTH FILTER
SSITWAVEFORMS OF LOAD CURRENT AND POWER FACTOR
USING APF
Load current Waveforms after connecting the APF to the distribution line
Power factor Waveforms after connecting the APF to the distribution line
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TOTAL HARMONIC DISTORTION
The THD is defined as the ratio of the rms value of the harmonic components to the rms value of the fundamental component and usually expressed in percent. This index is used to measure the deviation of a periodic wave form containing harmonics from a perfect sine wave. For a perfect sine wave at fundamental frequency, the THD is zero.
Thd > 5 , Harmonics are presentThd < 5 , Harmonics are absent
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FFT ANALYSIS OF LOAD CURRENT WITHOUT APF
SSITFFT ANALYSIS OF LOAD CURRENT
WITH APF
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ANALYSIS OF HARMONIC CURRENT
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APPLICATIONS
FACTS Devices
Smart GRID systems
HVDC converters
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CONCLUSION
On the basis of the simulation, the article utilizes the
instantaneous reactive power theory (ip-iq calculating approach) to
detect harmonic wave and reactive load current efficiently, compensate
the load current effectively by reshaping the source current to that
similar to sine wave and reducing the THD value to below 5%. The
compensation performance of the simulation result provides a practical
approach to the basis of APF application in smart grid system.
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Thank You
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Queries