scholarly journals Modeling a Dual-Mode Controller Design for a Quasi-Resonant Flyback Converter

2019 ◽  
Vol 9 (9) ◽  
pp. 1860
Author(s):  
Ching-Chun Chuang ◽  
Chih-Chiang Hua ◽  
Chong-Yu Huang ◽  
Li-Kai Jhou
Keyword(s):  
Controller Design ◽  
Circuit Simulation ◽  
Equivalent Circuit Model ◽  
Technological Advancement ◽  
Dual Mode ◽  
Heavy Load ◽  
Constant Frequency ◽  
Mode Control ◽  
Control Scheme ◽  
Load Conditions

The proposed system can overcome the disadvantage of a high peak current in quasi-resonant fly-back (QRF) converters when operated under heavy load conditions. The operating mode and control scheme of a QRF converter with dual-mode control were established and analyzed. The dual-mode control scheme not only enabled a valley-switching detection technique that satisfied the zero-voltage switching condition but also provided a constant frequency mechanism to reduce the conduction loss in QRF converters when operated in a continuous conduction mode and under heavy load conditions. The small-signal equivalent circuit model of QRF converter circuits was constructed using an average approximation method. The technological advancement of a QRF converter with a dual-mode controller was presented in this study. The circuit simulation result of the proposed QRF converter with a mix control scheme proved that the derived circuit component parameters meet the requirements of the converter.

scholarly journals Output Feedback Adaptive Dynamic Surface Sliding-Mode Control for Quadrotor UAVs with Tracking Error Constraints

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-23 ◽  
Author(s):  
Guoqiang Zhu ◽  
Sen Wang ◽  
Lingfang Sun ◽  
Weichun Ge ◽  
Xiuyu Zhang
Keyword(s):  
Sliding Mode Control ◽  
Output Feedback ◽  
Controller Design ◽  
Sliding Mode ◽  
Tracking Error ◽  
Control Process ◽  
Nonlinear Observer ◽  
Dynamic Surface ◽  
Mode Control ◽  
Control Scheme

In this paper, a fuzzy adaptive output feedback dynamic surface sliding-mode control scheme is presented for a class of quadrotor unmanned aerial vehicles (UAVs). The framework of the controller design process is divided into two stages: the attitude control process and the position control process. The main features of this work are (1) a nonlinear observer is employed to predict the motion velocities of the quadrotor UAV; therefore, only the position signals are needed for the position tracking controller design; (2) by using the minimum learning technology, there is only one parameter which needs to be updated online at each design step and the computational burden can be greatly reduced; (3) a performance function is introduced to transform the tracking error into a new variable which can make the tracking error of the system satisfy the prescribed performance indicators; (4) the sliding-mode surface is introduced in the process of the controller design, and the robustness of the system is improved. Stability analysis proved that all signals of the closed-loop system are uniformly ultimately bounded. The results of the hardware-in-the-loop simulation validate the effectiveness of the proposed control scheme.

Analysis and Design of a Dual-Mode Control Boost Rectifier

2012 ◽  
Vol 516-517 ◽  
pp. 1906-1909
Author(s):  
Yu Kang Lo ◽  
Jing Yuan Lin ◽  
Chao Fu Wang
Keyword(s):  
Switching Loss ◽  
Dual Mode ◽  
Analysis And Design ◽  
Design Procedures ◽  
Mode Control ◽  
Extreme Loads ◽  
Control Scheme ◽  
Boost Rectifier ◽  
Heavy Loads ◽  
Mode Tm

This paper presents a dual-mode control scheme for a boost rectifier at both extreme loads. The transition-mode (TM) technique is adopted to reduce the switching loss at light loads. On the other hand, the fixed-off-time (FOT) control with continuous conduction mode (CCM) operation decreases the conduction losses at heavy loads. The principles and design procedures of the proposed dual-mode controller are discussed and analyzed. Finally, a 300-W dual-mode boost rectifier with an output voltage of 380 V is implemented with satisfactory experimental results.

scholarly journals A Novel Stability Improvement Strategy for a Multi-Inverter System in a Weak Grid Utilizing Dual-Mode Control

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2144 ◽  
Author(s):  
Ming Li ◽  
Xing Zhang ◽  
Wei Zhao
Keyword(s):  
Current Source ◽  
Voltage Source ◽  
Output Current ◽  
Dual Mode ◽  
Improvement Strategy ◽  
Distributed Generations ◽  
Mode Control ◽  
Loop Transfer Function ◽  
Grid Impedance ◽  
Control Scheme

Due to the increasing penetration of distributed generations (DGS) and non-negligible grid impedance, the instability problem of the multi-inverter system operating in current source mode (CSM) is becoming serious. In this paper, a closed-loop transfer function model of such a multi-inverter system is established, by which it is concluded that output current resonance will occur with the increase in the grid impedance. In order to address this problem, this paper presents a novel dual-mode control scheme of multiple inverters: one inverter operating in CSM will be alternated into voltage source mode (VSM) if the grid impedance is high. It is theoretically proved that the coupling between the inverters and the resonance in the output current can be suppressed effectively with the proposed scheme. Finally, the validity of the proposed theory is demonstrated by extensive simulations and experiments.

An Accurate Low-Friction Pneumatic Position Control System

1989 ◽  
Vol 203 (3) ◽  
pp. 159-165 ◽  
Author(s):  
J A Linnett ◽  
M C Smith
Keyword(s):  
Control System ◽  
Position Control ◽  
Low Cost ◽  
Low Friction ◽  
Dual Mode ◽  
Pneumatic Control ◽  
Mode Control ◽  
Control Scheme ◽  
Position Control System

A fast, accurate, low-cost pneumatic control system in which the actuator can be programmed off-line to stop at any required position in its travel without the use of mechanical stops is described. A dual-mode control scheme switching two on/off valves is used. The system is able to position a 37 kg inertia load to within ± I mm at any point on a 300 mm stroke in less than a second.

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