一般電機驅動系統中，較常使用脈衝寬度調變的逆變器，並於直流鏈上搭配
大型電解電容器，以穩定該系統的直流鏈電壓。但因電解電容器體積過於龐大
及壽命短，為了解決此問題，許多文獻著力於消除或減少電解電容器，也因系
統使用較小的直流鏈電容器，會導致系統不穩定，因此本論文使用增加虛擬阻
抗的方式，來解決系統不穩定的問題。
而當電機驅動系統前級使用三相二極體整流器時，可視為是非線性的負載，
因此會造成系統產生諧波失真電流，為符合IEEE/Std519-1992規範，市電電流
總諧波失真(THDi)須小於5%，本文使用主動電力濾波器並搭配LLCL濾波器以
降低脈衝寬度調變逆變器之切換頻率所造成的高頻諧波。主動電力濾波器主要
由諧波萃取及電流控制器所組成。在諧波萃取部分本文使用二階低通濾波器，
而電流控制器則包括: 同步參考框下之PI控制器(PI-SRF)、雙重同步參考框下
之PI控制器(DSRF)、具多個旋轉積分於同步參考框下之PI控制器(PI-MRI)、具
比例調節器和正弦訊號積分器於靜止參考框控制器(PI-SSI)、具多個SSIs並於同
步參考框下之PI-SSI控制器(PI-SSI-SRF)。並比較上述電流控制器對於系統效能
影響。
本文也考慮因市電阻抗過大造成弱電網時，影響主動電力濾波器的效能，因
此加入共同連接點電壓補償控制器，根據模擬驗證，可使系統效能提升。
在負載條件為271kW的三相電機驅動系統中，模擬結果顯示在應用主動電力
濾波器後，使用P-SSI-SRF電流控制器補償諧波效果最佳。為了驗證其有效性並
進一步比較不同電流控制器的效能，使用Matlab/Simulink軟體進行了模擬。

In traditional motor drive systems, pulse width modulation inverters are extensively
utilized, while the stabilization of the DC-link voltage generally depends
on the use of substantial electrolytic capacitors. However, due to the excessively
large volume and short lifetime of the electrolytic capacitors, many studies have
focused on eliminating or reducing them. Using smaller DC-link capacitors can
lead to system instability. Therefore, this thesis proposes a solution to the instability
problem by adding virtual impedance, also known as active damping method
(ADMP).
When a diode rectifier is employed at the forefront of a motor drive system, it
can be regarded as a nonlinear load, which causes the system to generate harmonic
distortion currents. In order to comply with the IEEE/Std519-1992 specification,
the total harmonic distortion of the grid current (THDi) must be less than 5%.
This thesis presents a novel approach that advocates the integration of an active
power filter in conjunction with an LLCL filter to mitigate the adverse effects
of high-frequency harmonics arising from the switching frequency of the PWM
inverter. The active power filter primarily consists of a harmonic extraction unit
and a current regulation. An LPF is used for harmonic extraction in this thesis.
The current controllers include: a PI controller in synchronous reference frame (PISRF),
a double synchronous reference frame PI controller (DSRF), a PI controller
with multiple rotating integrators in synchronous reference frame (PI-MRI), a
proportional regulator and a sinusoidal signal integrator under stationary reference
frame controller (P-SSI), and a P-SSI controller with several SSIs in synchronous
reference frame (P-SSI-SRF). The effects of the above current controllers on system
performance are compared.
This thesis also considers the impact of weak grids caused by excessive grid
impedance on the performance of active power filters. Therefore, a point of common
coupling voltage compensation controller is added. According to simulations,
the system performance can be improved with the use of this controller.
The simulation results are employed in a three-phase diode rectifier and motor drive system with a load condition of 271 kW. Upon implementation of the APF,
a notable observation can be made: the P-SSI-SRF current controller demonstrates
better performance. In order to validate the efficacy of the findings, the
performance of various current controllers is simulated and compared using Matlab/
Simulink software.

Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I
摘要. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . III
致謝. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IV
Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V
List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .VIII
List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XII
Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .XIII
1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.1 Motivations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 Literature Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Contribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Instability Mechanism of a Diminished DC-Link Capacitor in
Motor Drive Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.2 Instability Mechanism . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.3 Active Damping Stabilization Method . . . . . . . . . . . . . . . . . 10
2.4 Source State Estimations . . . . . . . . . . . . . . . . . . . . . . . . 14
2.5 Constraints Imposed on DC-link Voltage Under Rapid Load Fluctuations
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.6 Complete Motor Drive System . . . . . . . . . . . . . . . . . . . . . 19
2.7 Reducing the DC-link Voltage Ripple Using ADMP Method . . . . 21
2.8 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3 Design of Active Power Filters . . . . . . . . . . . . . . . . . . . . . 26
3.1 Operational Principle . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.2 LLCL Passive Filter . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.3 Harmonic Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.4 Harmonic Current Controllers . . . . . . . . . . . . . . . . . . . . . 33
3.4.1 PI-SRF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.4.2 DSRF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.4.3 PI-MRI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
3.4.4 P-SSI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3.4.5 P-SSI-SRF . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
3.5 vPCC Compensation for the Weak Grid . . . . . . . . . . . . . . . . 39
3.6 APF Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
3.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4 Integrations of AC-Side Control and DC-Side Control . . . . . . 50
4.1 Harmonic Calculations in the AC-Side . . . . . . . . . . . . . . . . 50
4.2 Comparisons Between Theoretical Analysis and Simulation Results 55
4.3 Complete Control Block Diagrams . . . . . . . . . . . . . . . . . . . 56
4.3.1 DC Side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.3.2 DC Observer . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.3.3 Motor Side . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.3.4 AC Grid Side . . . . . . . . . . . . . . . . . . . . . . . . . . 60
4.3.5 DC/AC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.3.6 APF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5 Simulation Validations of the Complete System . . . . . . . . . . 63
5.1 APF with vPCC Compensation . . . . . . . . . . . . . . . . . . . . . 63
5.2 Grid Current Compensation by APF . . . . . . . . . . . . . . . . . 66
5.2.1 PI-SRF Control . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.2.2 DSRF Control . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.2.3 PI-MRI Control . . . . . . . . . . . . . . . . . . . . . . . . . 72
5.2.4 P-SSI Control . . . . . . . . . . . . . . . . . . . . . . . . . . 74
5.2.5 P-SSI-SRF Control . . . . . . . . . . . . . . . . . . . . . . . 74
5.3 Simulation Results Under Weak Grid Conditions . . . . . . . . . . . 78
5.4 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
6 Conclusion and Future Work . . . . . . . . . . . . . . . . . . . . . . 82
6.1 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
6.2 Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

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