Download Series Active Filters

EPEC 2011
Summary:
 Introduction
 Series Active Filters
 Summary
 Instantaneous power theory for voltage compensation
 Simulation results and discussions
 Shunt active filter controlled with p-q theory
 Series active filter controlled with p-q theory
 Voltage distortion compensation under a sinusoidal load
current
 Conclusion
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Introduction:
 Summary
 Introduction
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Series Active Filters:
 Series active filter is usually proposed to solve voltage distortions and
other related issues.
 They are more competent than shunt compensators as they are able to
compensate current issues.
 Summary
 Introduction
 Series Active
Filters:
Series Active Filter
Shunt Active Filter
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Series Active Filters:
• Similar structure with shunt active filters + connection transformer.
• SSeriesFilter= 3%-10% SLoad , SShuntFilter=30%-70% SLoad
 Summary
 Introduction
 Series Active
Filters:
Ac#ve Filter Solu#ons to Power Quality Problems Ac#ve Filter Connec#on Shunt Series A. Javadi
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Effect on supply Effect on load Current harmonic filtering Reac2ve current compensa2on Current unbalance Voltage flicker Current harmonic filtering Voltage sag/swell Reac2ve current compensa2on Voltage unbalance Current unbalance Voltage interrup2on Voltage flicker Voltage flicker Voltage unbalance Voltage notching EPEC 2011
Instantaneous power theory for
voltage compensation:
 Summary
 Introduction
 Series Active
Filters:
 P-q Theory
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Instantaneous power theory for
voltage compensation:
 Summary
 Introduction
 Series Active
Filters:
 P-q Theory
Instantaneous powers are divided into an
average value and an oscillating portion:
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Instantaneous power theory for
voltage compensation:
 Summary
 Introduction
 Series Active
Filters:
 P-q Theory
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Simulation results and discussions:
 Shunt current distortion compensation
 Summary
 Introduction
 Series Active
Filters:
 P-q Theory
 Simulation
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Specifica2on Parameters (Shunt compensa2on) Source 208V , 60 Hz Load 10 kVA , R=7.5 Ω, L= 50 mH Load series inductance 1 mH Ac2ve filter series inductance 1 mH Filter Capacitor 10 μF EPEC 2011
Simulation results and discussions:
 Shunt current distortion compensation
THDis=1.4%
 Summary
 Introduction
 Series Active
Filters:
 P-q Theory
 Simulation
va vb vc
ia ib ic
THDiL=21.76%
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Simulation results and discussions:
 Summary
 Introduction
 Series Active
Filters:
 P-q Theory
 Simulation
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Simulation results and discussions:
 Series voltage distortion compensation
(expected results, offline simulation)
 Summary
 Introduction
Three-phase Load
voltage
 Series Active
Filters:
 P-q Theory
 Simulation
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Simulation results and discussions:
 Series voltage distortion compensation
 Summary
 Introduction
Three-phase Source
voltage with distortion
 Series Active
Filters:
 P-q Theory
 Simulation
 Sinusoidal current
Three-phase Load
voltage
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Conclusion:
 If the load draws a sinusoidal wave form (which is not almost the
case), the SAF based on the p-q theory inject a voltage in order to have
a sinusoidal voltage wave form at the load side despite the presence of
any perturbation in the source. It will also compensate all the non-active
power, including the reactive an oscillating portion of active power, and
the source will only supply a constant active power.
 Summary
 Introduction
 Series Active
Filters:
 P-q Theory
 If the non active powers are compensated the voltage is then
distorted, so this strategy could not satisfy the critical load.
 Simulation
 Sinusoidal current
 Conclusion
 The “instantaneous p-q theory” could not be used for a series active
filter and the constant power strategy is not convenient for the series
compensation.
 By changing the strategy of compensation from a constant power to a
sinusoidal wave strategy it could be possible to overcome the issue.
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