Direct Power and Torque Control of AC/DC/AC Converter-Fed ...

More documents

Recommendations

Info

4. Direct Power and Torque Control with Space Vector Modulation – DPTC-SVM Based on above considerations it can be concluded that introduced active power feedforward has no negative impact on the line current. This can be derived analytically. Please consider rotating reference frame concurrently with virtual flux (Subsection 2.5.4). With assumption that the system is decoupled, and meets the unity power factor condition i.e. I = 0 the following equations can be derived: dI L dt Ly dU C dt dI L dt Ly dI L dt I Lyc Ly py Ly Lx = U −U − RI (4.79) U dc py = ILy − Iload (4.80) Udc Ii1 ( I − I ) KPi 1 = Lyc Ly (4.81) T K ( U −U ) Lyc PU = dcc dc (4.82) TIU PU Then, VSR voltage: U py ( U −U ) = K (4.83) Pi dcc dc [ K ( U −U ) + I − I ] = K 1 (4.84) PU dcc dc PF Where, I PF – current proportional to signal of the active power feedforward – PF Hence, during steady state operation above equations yields: = U Ly − KPi 1 [ KPU ( Udcc −Udc ) + I PF − I y ] − RILy y 0 (4.85) = ILy 1 Udc [ K ( U −U ) + I − I ] { KPi PU dcc dc PF y } − Iload 1 0 (4.86) K ( K ( U −U ) − I ) = K ( U −U ) ( − I ) Pi1 0 = PU dcc dc Ly PU dcc dc Ly (4.87) TIi 1 Substituting Eq.(4.93) into Eqs. (4.91) and (4.92): 0 I − RI (4.88) = U Ly − KPi 1 1 PF Ly load dcc 0 = I Ly KPi 1IPF − Iload ⇒ KPi 1IPF = (4.89) U dcc ILy Based on Eq.(4.95) the current from active power feedforward can be eliminated: I U 78
4. Direct Power and Torque Control with Space Vector Modulation – DPTC-SVM I U load dcc 0 = U Ly − − RILy (4.90) ILy From Eq. (4.96) it can be seen that steady states do not depends on active power feedforward. Further, based on Eq. (4.96) a stationary error elimination condition can be defined as: 2 RI −U I − I U = 0 (4.91) Ly Ly Ly load dcc If the solutions are real the stationary error is eliminated. It takes place for: I When: I Ly1/ 2 load U 2 U Ly ± U Ly − 4RIloadU dcc = (4.92) 2R dcc 2 U Ly < (4.93) 4R 4.3.2. AC/DC/AC Converter-Fed IM Drive Operated with Closed Torque Control Loop In Fig. 4. 5 oscillograms illustrate operation with torque control loop. Torque reversal is applied when the mechanical speed reach +/- 71 % of nominal speed. From Fig. 4. 5 can be seen very good stabilization of DC-link voltage through PF Ω and PF UI . Moreover, for 10 time reduced DC-link capacitor C=47uF as in Fig. 4. 6 that qualifications are also true. Moreover, as it can be seen in Fig. 4. 7 higher gain of DC-link voltage controller (i.e. with proportional gain as for C=470uF) improves significantly the quality of the DC-link voltage stabilization in all cases. 79
Page 1 and 2:
POLITECHNIKA WARSZAWSKA WARSAW UNIV
Page 3 and 4:
Acknowledgements The work presented
Page 5 and 6:
Contents 4.2.2. Energy of the DC-li
Page 7 and 8:
Chapter 1 1. Introduction 1.1. AC/D
Page 9 and 10:
1. Introduction Tab. 1. 1. Current
Page 11 and 12:
1. Introduction DC-link voltage to
Page 13 and 14:
1. Introduction then nominal speed
Page 15 and 16:
1. Introduction [69]. From that tim
Page 17 and 18:
Chapter 2 2. Voltage Source Convert
Page 19 and 20:
2. Voltage Source Converters - VSC
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34: 2. Voltage Source Converters - VSC
Page 39 and 40: Chapter 3 3. Vector Control Methods
Page 41 and 42: 3. Vector Control Methods of AC/DC/
Page 75 and 76: Chapter 4 4. Direct Power and Torqu
Page 77 and 78: 4. Direct Power and Torque Control
Page 83: 4. Direct Power and Torque Control
Page 99 and 100: Chapter 5 5. Passive Components Des
Page 101 and 102: 5. Passive Components Design 5.2.2.
Page 103 and 104: 5. Passive Components Design a) b)
Page 105 and 106: 5. Passive Components Design C T
Page 107 and 108: 5. Passive Components Design Theref
Page 109 and 110: 5. Passive Components Design motor
Page 111 and 112: Chapter 6 6. Simulation an Experime
Page 113 and 114: 6. Simulation and Experimental Resu
Page 129 and 130: Chapter 7 7. Summary and Conclusion
Page 131 and 132: 7. Summary and Conclusion • easy
Page 133 and 134: References [18] G. Buja, M. P. Kazm
Page 135 and 136:
References [58] J. G. Kassakian, M.
Page 137 and 138:
References [96] H. Mao, D. Boroyevi
Page 139 and 140:
References [133] A. Tripathi, A. M.
Page 141 and 142:
References [167] M. Jasiński, D.
Page 143 and 144:
Symbols Employed I L - I LA I r - r
Page 145 and 146:
Symbols Employed U pA ,U pB , U pC
Page 147 and 148:
A. Appendices A.1. Space vector in
Page 149 and 150:
Appendices In the special condition
Page 151 and 152:
Appendices A.2. Coordinate Transfor
Page 153 and 154:
Appendices S 3 UI 2 m s * * = = - a
Page 155 and 156:
Appendices Tab. A. 4. 3. Date of th
Page 157 and 158:
Appendices LINE L1 L C F Fig. A. 4.
Page 159 and 160:
Appendices Tab. A. 4. 6. Data of th
show all

Direct Power and Torque Control of AC/DC/AC Converter-Fed ...

Create successful ePaper yourself

Delete template?

Save as template?