scholarly journals Nonlinear Robust Disturbance Attenuation Control Design for Static Var Compensator in Power System

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Ting Liu ◽  
Nan Jiang ◽  
Yuanwei Jing ◽  
Siying Zhang
Keyword(s):  
Control Method ◽  
Short Circuit ◽  
Parameter Estimate ◽  
Disturbance Attenuation ◽  
Static Var Compensator ◽  
Worst Case ◽  
Nonlinear Parameterization ◽  
Ground Fault ◽  
Unknown Disturbances ◽  
Robust Disturbance Attenuation

The problem of designing an adaptive backstepping controller for nonlinear static var compensator (SVC) system is addressed adopting two perspectives. First, instead of artificially assuming an upper bound or inequality scaling, the minimax theory is used to treat the external unknown disturbances. The system is insensitive to effects of large disturbances due to taking into account the worst case disturbance. Second, a parameter projection mechanism is introduced in adaptive control to force the parameter estimate within a prior specified interval. The proposed controller handles the nonlinear parameterization without compromising control smoothness and at the same time the parameter estimate speed is improved and the robustness of system is strengthened. Considering the short-circuit ground fault and mechanical power perturbation, a simulation study is carried out. The results show the effectiveness of the proposed control method.

A Voltage Control Method of Static Var Compensator for the Remote System Interconnected by Long Distance AC Cables

2011 ◽  
Vol 131 (11) ◽  
pp. 896-904
Author(s):  
Yuji Tamura ◽  
Shinji Takasaki ◽  
Yasuyuki Miyazaki ◽  
Hideo Takeda ◽  
Shoichi Irokawa ◽  
...  
Keyword(s):  
Control Method ◽  
Voltage Control ◽  
Static Var Compensator ◽  
Long Distance ◽  
Remote System

Optimized Non-Dead-Time Control of Inverter with Two-Phase Modulated SVPWM

2012 ◽  
Vol 562-564 ◽  
pp. 1531-1536
Author(s):  
Ming Xing Zhu ◽  
Jing Bo Shi
Keyword(s):  
Control Strategy ◽  
Pulse Width Modulation ◽  
Dead Time ◽  
Control Method ◽  
Short Circuit ◽  
Two Phase ◽  
Zero Crossing ◽  
Time Control ◽  
Bus Voltage ◽  
Current Zero

In the inverter control system, two-phase modulated space vector pulse width modulation (SVPWM) algorithm has the advantages of minimum switch loss and higher utilization of direct current (DC) bus voltage. Non-dead-time control strategy can eliminate the problems of the dead time effects. But the traditional non-dead-time control strategy heavily depends on the current zero-crossing detection, which may cause the output voltage distortion or even a short circuit. Based on the analysis of the reason for the distortion, a new optimized non-dead-time control method is proposed. Two methods for the detection of the overlapping area are enumerated. The conclusions are confirmed by the simulation results with MATLAB/ SIMULINK.

Collision prediction and avoidance for satellite ultra-close relative motion with zonotope-based reachable sets

2018 ◽  
Vol 233 (11) ◽  
pp. 3920-3937
Author(s):  
Zhanpeng Xu ◽  
Xiaoqian Chen ◽  
Yiyong Huang ◽  
Yuzhu Bai ◽  
Qifeng Chen
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Control Method ◽  
Reachable Sets ◽  
Close Relative ◽  
Worst Case ◽  
Reference Orbit ◽  
Robust Model Predictive Control ◽  
Collision Prediction ◽  
Robust Model

Collision prediction and avoidance are critical for satellite proximity operations, and the key is the treatment of satellites' motion uncertainties and shapes, especially for ultra-close autonomous systems. In this paper, the zonotope-based reachable sets are utilized to propagate the uncertainties. For satellites with slender structures (such as solar panels), their shapes are simplified as cuboids which is a special class of zonotopes, instead of the classical sphere approach. The domains in position subspace influenced by the uncertainties and shapes are determined, and the relative distance is estimated to assess the safety of satellites. Moreover, with the approximation of the domains, the worst-case uncertainties for path constraints are determined, and a robust model predictive control method is proposed to deal with the line of sight and obstacle avoidance constraints. With zonotope representations of satellites, the proposed robust model predictive control is capable of handling the shapes of the satellite and obstacle simultaneously. Numerical simulations demonstrate the effectiveness of the proposed methods with an elliptic reference orbit. 1

scholarly journals Design Methodology of Tightly Regulated Dual-Output LLC Resonant Converter Using PFM-APWM Hybrid Control Method

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2146
Author(s):  
HwaPyeong Park ◽  
Mina Kim ◽  
HakSun Kim ◽  
JeeHoon Jung
Keyword(s):  
Design Methodology ◽  
Control Method ◽  
Hybrid Control ◽  
Pulse Frequency ◽  
Voltage Regulation ◽  
Resonant Converter ◽  
Pulse Frequency Modulation ◽  
Load Range ◽  
Worst Case ◽  
Llc Resonant Converter

A dual-output LLC resonant converter using pulse frequency modulation (PFM) and asymmetrical pulse width modulation (APWM) can achieve tight output voltage regulation, high power density, and high cost-effectiveness. However, an improper resonant tank design cannot achieve tight cross regulation of the dual-output channels at the worst-case load conditions. In addition, proper magnetizing inductance is required to achieve zero voltage switching (ZVS) of the power MOSFETs in the LLC resonant converter. In this paper, voltage gain of modulation methods and steady state operations are analyzed to implement the hybrid control method. In addition, the operation of the hybrid control algorithm is analyzed to achieve tight cross regulation performance. From this analysis, the design methodology of the resonant tank and the magnetizing inductance are proposed to compensate the output error of both outputs and to achieve ZVS over the entire load range. The cross regulation performance is verified with simulation and experimental results using a 190 W prototype converter.

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