HARMONIC REDUCTION IN POWER SYSTEM Ankit Vashi B.E. ...

More documents

Recommendations

Info

2.4.1 Active Harmonic Filter: As explained earlier, the active harmonic filters are used for low voltages where reactive power requirement is low. The way this filter works is, the output load with the voltage waveform is obtained by boosting the voltage throughout each half cycle by the filter. The voltage which is thus produced tends to rectifiers in the power supply to gain current. The duty cycle and power factor are thus improved. Depending on the active harmonic filter used, the output distortion is reduced. Also, current that is produced due to load is monitored by the harmonic filter and generates a waveform which coincides with the exact shape of the nonlinear portion of the load current. [3][5] 2.4.2 Passive Harmonic Filter: As shown before, the passive harmonic filters are such that they are used for different voltage levels. In case of passive harmonic filters, the harmonics are reduced by using series or parallel resonant filters. The way these passive harmonic filters works is, a filter connected in parallel with the load and in series with inductance and capaciteance is a current acceptor. A current acceptor is a parallel filter which is in parallel with the load and is in series with the inductance and capacitance. The filter which is near the resonant frequency of the parallel array provides maximum attenuation. The filter passes as much current as the harmonic voltage nears the filter resonant point. The passive filters thus eliminate the harmonics. If the individual load requirement is more than that of the input load, the harmonic current should be eliminated. A capacitor in series with 8
an inductance is a passive filter. The reduced harmonic frequency must be equal to the resonant frequency of the circuit. The impedance of the network and the low impedance of the filter thus eliminate the harmonic current. [3][5] More detailed explanation of Active and Passive Harmonic filters used in Power System will be explained in detail in next chapter. 9
Page 1 and 2: HARMONIC REDUCTION IN POWER SYSTEM
Page 3 and 4: I certify that this student has met
Page 5 and 6: TABLE OF CONTENTS List of Figures
Page 7 and 8: LIST OF FIGURES 1. Figure 1: Single
Page 9 and 10: Chapter 1 INTRODUCTION The term har
Page 11 and 12: 2.2 Transients: In terms of power s
Page 13 and 14: obtained during the event is consid
Page 15: Non-linear loads are considered as
Page 19 and 20: 3.2 Roles of Filters in Power Syste
Page 21 and 22: 3.3.1 Types of Passive Filters: The
Page 23 and 24: Figure 4 : Three Phase, Three Wire
Page 25 and 26: 3.4 Active Filters : Active filters
Page 27 and 28: Figure 9 : Single Phase Active Filt
Page 29 and 30: Theoretically the output voltage wa
Page 31 and 32: consists of four IGBT devices (also
Page 33 and 34: 4.2.3 Multi Level Inverters : Figur
Page 35 and 36: converters, the main objective is t
Page 37 and 38: order to reduce the harmonics is kn
Page 39 and 40: Note: For figures 16 and 17, • ts
Page 41 and 42: Figure 18 : Plot of Switching angle
Page 47 and 48: cos(7*s1)-cos(7*s2)+cos(7*s3)-cos(7
Page 49: REFERENCES 1.) Roger C. Dugan, Mark

HARMONIC REDUCTION IN POWER SYSTEM Ankit Vashi B.E. ...

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?