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highest harmonic number. The change in the frequency plot each time a filter is turned off should be examined. 20A 20A 15A 15A Line Current 10A Line Current 10A 5A 5A 0A 50Hz 100Hz 200Hz 300Hz 400Hz 500Hz 600Hz 700Hz 0A 50Hz 100Hz 200Hz 300Hz 400Hz 500Hz 600Hz 700Hz Frequency Frequency (a) The frequency plot of 5 th , 7 th , 11 th , and 13 th shunt harmonic filters. (b) The frequency plot of 5 th , 7 th , and 11 th shunt harmonic filters. 20A 20A 15A 15A Line Current 10A Line Current 10A 5A 5A 0A 50Hz 100Hz 200Hz 300Hz 400Hz 500Hz 600Hz 700Hz Frequency 0A 50Hz 100Hz 200Hz 300Hz 400Hz 500Hz 600Hz 700Hz Frequency (c) The frequency plot of 5 th , and 7 th shunt harmonic filters. (d) The frequency plot of 5 th harmonic filter. Figure 2.7: The frequency characteristics of several harmonic filters connected in parallel. The system structure is the same as Figure 2.6 except that the filters are tuned to the harmonic frequencies this time. Unlike the above case, when TSC stages are chosen to filter the same frequency harmonics, the filters work more efficiently. The reactive power compensation is achieved, which is the main purpose, at the same time whichever stage is on, the required harmonic is filtered out without any distortion in frequency characteristics. It is obvious from Figure 2.8 that switching thyristors on and off has no effect on neither parallel resonance amplitude, nor series resonance frequency. Therefore it can be concluded that harmonic filtering has a second importance in a TSC design to obtain a stable operation. This characteristics of TSC is valuable if and only if it is used for one specific harmonic filtration. 2.2.3 Terminal Voltage Regulation Many electronic devices are exposed to voltage variations due to the change in load type or load number connected to the electricity network. The varia- 20
20A 20A 15A 15A Line Current 10A Line Current 10A 5A 5A 0A 50Hz 100Hz 200Hz 300Hz 400Hz 500Hz 600Hz 700Hz Frequency (a) The frequency plot of 5 th harmonic filter with four branches on. 0A 50Hz 100Hz 200Hz 300Hz 400Hz 500Hz 600Hz 700Hz Frequency (b) The frequency plot of 5 th harmonic filter with three branches on. 20A 20A 15A 15A Line Current 10A Line Current 10A 5A 5A 0A 50Hz 100Hz 200Hz 300Hz 400Hz 500Hz 600Hz 700Hz Frequency (c) The frequency plot of 5 th harmonic filter with two branches on. 0A 50Hz 100Hz 200Hz 300Hz 400Hz 500Hz 600Hz 700Hz Frequency (d) The frequency plot of 5 th harmonic filter with one branch on. Figure 2.8: The frequency characteristics of 5 th harmonic filters connected in parallel. The system structure is the same as Figure 2.6 except that the filters are tuned to 5 th harmonic frequency. tions appear as voltage dips, rapid fluctuations in amplitude, or even voltage avalanches. As a result, some faults occur at critical parts of the electronic devices since their operating principle depends on the zero crossing of the voltage and current waveforms. In addition, high voltage may cause a breakdown of the insulation. Therefore, the voltage at the supply end must be kept constant to avoid all these problems. If the single phase Thévenin equivalent circuit of a power system is represented by Figure 2.9(a), the variation in voltage amplitude can be expressed as: ∆V = V S − V L , (2.3) where V S is the voltage at the source end, V L is the voltage at the load end. When we assume that (R s +jX s ) is the source impedance, the voltage difference can also be expressed in terms of load current I L as: 21
Page 1 and 2: DESIGN AND IMPLEMENTATION OF THYRIS
Page 3 and 4: I hereby declare that all informati
Page 5 and 6: ÖZ TRİSTÖR ANAHTARLAMALI ŞÖNT
Page 7 and 8: ACKNOWLEDGMENTS I would like to exp
Page 9 and 10: 2.3 Switching Performance of TSC .
Page 11 and 12: LIST OF TABLES TABLES Table 1.1 Cur
Page 13 and 14: Figure 2.9 (a) Equivalent circuit r
Page 15 and 16: Figure 4.8 Resultant line-to-line v
Page 17 and 18: Figure 4.38 3 Phase current wavefor
Page 19 and 20: CHAPTER 1 INTRODUCTION 1.1 Power Qu
Page 21 and 22: this disturbance since they do not
Page 23 and 24: driving algorithm and it has to wit
Page 25 and 26: how to improve the transient respon
Page 27 and 28: From the practical view, the less t
Page 29 and 30: CHAPTER 2 PROBLEM DEFINITION AND PR
Page 31 and 32: as switching devices instead of ant
Page 33 and 34: Directly Connected Clients 35 33 30
Page 35 and 36: 2.2.2 Harmonic Filtration A pure si
Page 37: components dramatically. The follow
Page 41 and 42: VS RS XS VL Source Load IL Ic Compe
Page 43 and 44: a couple of cycles. However, at lea
Page 45 and 46: i + + VT - T1 T2 V + VC - L C Figur
Page 47 and 48: 2.15 shows that there are some comp
Page 49 and 50: waveform directly follows the sourc
Page 51 and 52: is known as copper loss of the tran
Page 53 and 54: components parallel to the thyristo
Page 55 and 56: Ls Coupling Transformer V TCR TSC L
Page 57 and 58: +1.0 Reactive Power, Q (pu) Inducti
Page 59 and 60: V V max V max = voltage limit I Cma
Page 61 and 62: power system. Voltage source conver
Page 63 and 64: timing of switching must be when th
Page 65 and 66: Table 3.1: Type of the excavators a
Page 67 and 68: 3.3 Selection Criterion of Capacito
Page 69 and 70: minutes should be given to self-dis
Page 71 and 72: possible in order to achieve a tran
Page 73 and 74: advantage. It is not affected by th
Page 75 and 76: (a) (b) Figure 3.7: PSCAD model of
Page 77 and 78: this value is at least twice of the
Page 79 and 80: of the reverse recovery current and
Page 81 and 82: curve in its datasheet should be ta
Page 83 and 84: Figure 3.13: The current distributi
Page 85 and 86: stays in inductive or capacitive re
Page 87 and 88: ”ENB A, ENB B and ENB C” are co
Page 89 and 90:
3.7 Key Points in Design of TSC Cab
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chapter, some basic calculations to
Page 93 and 94:
CHAPTER 4 EXPERIMENTAL RESULTS 4.1
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(a) Contactor Switched Plain Capaci
Page 97 and 98:
ated capacitor current. This inrush
Page 99 and 100:
current. Line-to-line voltage is al
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(a) Three phase current waveform at
Page 103 and 104:
4.2.2 Contactor Switched Shunt Filt
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to high inrush current causes a con
Page 107 and 108:
(a) Voltage Waveform across the cap
Page 109 and 110:
Page 111 and 112:
This transient has also negligible
Page 113 and 114:
(a) Three phase current waveform at
Page 115 and 116:
Figure 4.17: Resultant 3φ Capacito
Page 117 and 118:
Page 119 and 120:
Figure 4.21: Resultant line-to-line
Page 121 and 122:
Figure 4.24: Firing pulses, voltage
Page 123 and 124:
566 uF 2x6.0 MVA TM 34.5 kV 500 / 5
Page 125 and 126:
Experimental results will be presen
Page 127 and 128:
+1.6 +0.66 Thyristor Voltage (kV) -
Page 129 and 130:
+1.5 +1.0 Capacitor Voltage (kV) +0
Page 131 and 132:
+1.5 +1.0 Capacitor Voltage (kV) +0
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increase in current can be approxim
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would be given to the supply voltag
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250 1 cycle transient fft 200 I Pha
Page 139 and 140:
4.4 TSC Cabinet Interior Equipment
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4.5 Discussion In contactor or thyr
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• Delta-connected TSC topology is
Page 145 and 146:
[13] Tabandeh, M., Alavi, M.H., Mar
Page 147 and 148:
[38] Bilgin, H.F., “Design and Im
Page 149 and 150:
Since the roots of this equation ar
Page 151 and 152:
APPENDIX B DISTINCTIVE CURVES OF TH
Page 153 and 154:
135 Figure B.2: Stored charge and r
Page 155 and 156:
APPENDIX C DETAILS OF THE CONTROL C
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139 Figure C.2: P-CAD 2002 Schemati
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Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
147 Figure C.10: P-CAD 2002 Schemat
Page 167 and 168:
149 Figure D.1: General view of the
Page 169 and 170:
APPENDIX E APPLICATION MODEL OF THE
Page 171 and 172:
153 Figure E.2: 3 dimensional plot
Page 173 and 174:
155 Figure F.1: Installed SVC syste
Page 175 and 176:
157 Figure F.3: Installed SVC syste
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