可再生能源(Renewable Energy Resources, RERs)逐漸地增加，使得作為電網以及可再生能源兩端之間常用介面的併網型LCL濾波器電壓源換流器(Grid-connected voltage source inverter with LCL filter, LCL-VSI)的需求也因此提升。然而，發生於諧振頻率點的增益會導致在弱電網(Weak grid)的情況下造成系統不穩定亦或是因注入諧波而造成電網的失真。
本論文提出具有主動式阻尼及觀測器系統的最佳化滑動模式控制(Optimal Sliding Mode Control, OSMC)策略。本論文提出的控制策略能以較少需求的感測器(Sensors)來實現控制目標。此外，相比於先進的控制策略，本論文的控制表現更加優越。所有比較的結果在硬體迴路(Hardware-In-The-Loop, HIL)模擬中進行驗證，證明了所提方法的表現。

Renewable energy resources (RERs) have been gradually increasing. The grid-connected voltage source inverter (VSI) with LCL filter is the usual interface between RER and power grid. However, high peak resonance at the resonant frequency
may occur and cause the system to be unstable under weak grid condition or grid
distorted by harmonic injections.
This thesis proposes an active damping based and observer based optimal sliding
mode control (OSMC). The OSMC requires very few sensors to achieve the control
objective. Also, the control performance is superior compared to some of the stateof-the-art method. All the results are validated in a hardware-in-the-loop (HIL) setup, justifying the performance of the proposed method.

[1] F. Blaabjerg, R. Teodorescu, M. Liserre, and A. Timbus, Overview of control
and grid synchronization for distributed power generation systems, IEEE
Transactions on Industrial Electronics, vol. 53, no. 5, pp. 13981409, 2006.
[2] N. Mohan, T. Undeland, and W. Robbins, Power electronics: converters,
applications, and design, ser. Power Electronics: Converters, Applications,
and Design. John Wiley & Sons, 2003. [Online]. Available: https:
//books.google.com.tw/books?id=ToYoAQAAMAAJ
[3] X. Li, J. Fang, Y. Tang, X. Wu, and Y. Geng, Capacitor-voltage feedforward
with full delay compensation to improve weak grids adaptability of lcl-filtered
grid-connected converters for distributed generation systems, IEEE Transac-
tions on Power Electronics, vol. 33, no. 1, pp. 749764, 2018.
[4] S. A. Khajehoddin, M. Karimi-Ghartemani, P. K. Jain, and A. Bakhshai, A
control design approach for three-phase grid-connected renewable energy resources,
 IEEE Transactions on Sustainable Energy, vol. 2, no. 4, pp. 423432,
2011.
[5] W. Wu, Y. He, T. Tang, and F. Blaabjerg, A new design method for the
passive damped lcl and llcl filter-based single-phase grid-tied inverter, IEEE
Transactions on Industrial Electronics, vol. 60, no. 10, pp. 43394350, 2013.
[6] X. Li, X. Wu, Y. Geng, X. Yuan, C. Xia, and X. Zhang, Wide damping
region for lcl-type grid-connected inverter with an improved capacitor-currentfeedback
method, IEEE Transactions on Power Electronics, vol. 30, no. 9, pp.
52475259, 2015.
[7] Y. Liu, W. Wu, Y. He, Z. Lin, F. Blaabjerg, and H. S. Chung, An ecient
and robust hybrid damper for lcl- or llcl-based grid-tied inverter with strong
grid-side harmonic voltage eect rejection, IEEE Transactions on Industrial
Electronics, vol. 63, no. 2, pp. 926936, 2016.
[8] D. Pan, X. Ruan, C. Bao, W. Li, and X. Wang, Optimized controller design
for lcl-type grid-connected inverter to achieve high robustness against grid-impedance variation, IEEE Transactions on Industrial Electronics, vol. 62,
no. 3, pp. 15371547, 2015.
[9] M. T. Faiz, M. M. Khan, X. Jianming, M. Ali, S. Habib, K. Hashmi, and
H. Tang, Capacitor voltage damping based on parallel feedforward compensation
method for lcl-filter grid-connected inverter, IEEE Transactions on In-
dustry Applications, vol. 56, no. 1, pp. 837849, 2020.
[10] Z. Xin, P. C. Loh, X. Wang, F. Blaabjerg, and Y. Tang, Highly accurate
derivatives for lcl-filtered grid converter with capacitor voltage active damping,
IEEE Transactions on Power Electronics, vol. 31, no. 5, pp. 36123625, 2016.
[11] T. Dragi£evi¢, C. Zheng, J. Rodriguez, and F. Blaabjerg, Robust quasipredictive
control of lcl-filtered grid converters, IEEE Transactions on Power
Electronics, vol. 35, no. 2, pp. 19341946, 2020.
[12] Y. Guan, Y. Wang, Y. Xie, Y. Liang, A. Lin, and X. Wang, The dual-current
control strategy of grid-connected inverter with lcl filter, IEEE Transactions
on Power Electronics, vol. 34, no. 6, pp. 59405952, 2019.
[13] R. P. Vieira, L. T. Martins, J. R. Massing, and M. Stefanello, Sliding mode
controller in a multiloop framework for a grid-connected vsi with lcl filter,
IEEE Transactions on Industrial Electronics, vol. 65, no. 6, pp. 47144723,
2018.
[14] M. Ben Saïd-Romdhane, M. W. Naouar, I. Slama-Belkhodja, and E. Monmasson,
Robust active damping methods for lcl filter-based grid-connected converters,
 IEEE Transactions on Power Electronics, vol. 32, no. 9, pp. 67396750,
2017.
[15] R. Peña-Alzola, M. Liserre, F. Blaabjerg, M. Ordonez, and T. Kerekes, A selfcommissioning
notch filter for active damping in a three-phase lcl -filter-based
grid-tie converter, IEEE Transactions on Power Electronics, vol. 29, no. 12,
pp. 67546761, 2014.
[16] E. Wu and P. Lehn, Digital current control of a voltage source converter with
active damping of lcl resonance, in Twentieth Annual IEEE Applied Power Electronics Conference and Exposition, 2005. APEC 2005., vol. 3, 2005, pp.
16421649 Vol. 3.
[17] J. Kukkola and M. Hinkkanen, Observer-based state-space current control for a
three-phase grid-connected converter equipped with an lcl filter, IEEE Trans-
actions on Industry Applications, vol. 50, no. 4, pp. 27002709, 2014.
[18] B. Guo, M. Su, H. Wang, Z. Tang, Y. Liao, L. Zhang, and
S. Shi, Observer-based second-order sliding mode control for gridconnected
vsi with lcl-type filter under weak grid, Electric Power
Systems Research, vol. 183, p. 106270, 2020. [Online]. Available: http:
//www.sciencedirect.com/science/article/pii/S0378779620300778
[19] B. Wang, Y. Xu, Z. Shen, J. Zou, C. Li, and H. Liu, Current control of gridconnected
inverter with lcl filter based on extended-state observer estimations
using single sensor and achieving improved robust observation dynamics, IEEE
Transactions on Industrial Electronics, vol. 64, no. 7, pp. 54285439, 2017.
[20] H. Eldeeb, A. Massoud, A. S. Abdel-Khalik, and S. Ahmed, A
sensorless kalman filter-based active damping technique for grid-tied
vsi with lcl filter, International Journal of Electrical Power and
Energy Systems, vol. 93, pp. 146  155, 2017. [Online]. Available:
http://www.sciencedirect.com/science/article/pii/S0142061517304520
[21] R. K. Subroto, C. Z. Wang, and K. L. Lian, Four-wheel independent drive
electric vehicle stability control using novel adaptive sliding mode control,
IEEE Transactions on Industry Applications, vol. 56, no. 5, pp. 59956006,
2020.
[22] R. K. Subroto, Vehicle stability control of 4wd electric vehicle using combined
adaptive sliding mode controller and control allocation method, in 2017
IEEE 3rd International Future Energy Electronics Conference and ECCE Asia
(IFEEC 2017 - ECCE Asia), 2017, pp. 812817.
[23] X. Hao, X. Yang, T. Liu, L. Huang, and W. Chen, A sliding-mode controller
with multiresonant sliding surface for single-phase grid-connected vsi with an lcl filter, IEEE Transactions on Power Electronics, vol. 28, no. 5, pp. 22592268,
2013.
[24] N. Altin, S. Ozdemir, H. Komurcugil, and I. Sefa, Sliding-mode control in natural
frame with reduced number of sensors for three-phase grid-tied lcl-interfaced
inverters, IEEE Transactions on Industrial Electronics, vol. 66, no. 4, pp. 2903
2913, 2019.
[25] Y. Han, M. Yang, H. Li, P. Yang, L. Xu, E. A. A. Coelho, and J. M. Guerrero,
Modeling and stability analysis of lcl -type grid-connected inverters: A
comprehensive overview, IEEE Access, vol. 7, pp. 114 975115 001, 2019.
[26] D. S. Naidu, Optimal Control Systems. Boca Raton, Florida: CRC Press,
2002.
[27] A. Bryson, Optimal control-1950 to 1985, IEEE Control Systems Magazine,
vol. 16, no. 3, pp. 2633, 1996.
[28] T. Basar, Contributions to the Theory of Optimal Control, 2001, pp. 147166.
[29] J. E. Slotine and W. Li, Applied Nonlinear Control. Englewood Clis, NJ:
Prentice-Hall, 1991.
[30] V. Utkin, Variable structure systems with sliding modes, IEEE Transactions
on Automatic Control, vol. 22, no. 2, pp. 212222, 1977.
[31] J. Y. Hung, W. Gao, and J. C. Hung, Variable structure control: a survey,
IEEE Transactions on Industrial Electronics, vol. 40, no. 1, pp. 222, 1993.
[32] F. De Andrade, M. Castilla, and B. D. Bonatto, Basic Tutorial on Simulation
of Microgrids Control Using MATLAB® & Simulink® Software. Springer
Nature, 2020.
[33] W. Gao, Y. Wang, and A. Homaifa, Discrete-time variable structure control
systems, IEEE Transactions on Industrial Electronics, vol. 42, no. 2, pp. 117
122, 1995.
[34] A. Tewari, Modern Control Design: With MATLAB and SIMULINK.
Wiley, 2002. [Online]. Available: https://books.google.com.tw/books?id=
hZ-PPgAACAAJ
[35] B. D. O. Anderson and J. B. Moore, Optimal Control Linear Quadratic Methods.
Mineola, New York: Dover Publications, Inc, 2007.
[36] K. Hussain, R. Allwyn, R. Zepherin, and M. Shantha, Comparison of pid
controller tuning methods with genetic algorithm for foptd system, 2014.
[37] K. Lian and P. Lehn, Real-time simulation of voltage source converters based
on time average method, IEEE Transactions on Power Systems, vol. 20, no. 1,
pp. 110118, 2005.
[38] D. Yang, X. Wang, and F. Blaabjerg, Fast power control for vscs to enhance
the synchronization stability in ultra-weak grids, in 2018 IEEE Power Energy
Society General Meeting (PESGM), 2018, pp. 16.
[39] A. Egea-Alvarez, S. Fekriasl, F. Hassan, and O. Gomis-Bellmunt, Advanced
vector control for voltage source converters connected to weak grids, IEEE
Transactions on Power Systems, vol. 30, no. 6, pp. 30723081, 2015.
[40] M. Glinka and R. Marquardt, A new ac/ac multilevel converter family, IEEE
Transactions on Industrial Electronics, vol. 52, no. 3, pp. 662669, 2005.