Non-linear Control Techniques of LIMs

The switched mode dc-dc converters are some of the most widely used power electronics circuits because of high conversion efficiency and flexible output voltage. Many methods have been developed for the control of dc-dc converters. This paper deals with design of controller for dc-dc buck converter using various control techniques. The first two control techniques are based on classical or linear control methods i.e. PI and PID control, while the other two control technique are based on non linear control method i.e. Sliding Mode Control (SMC) and Sliding Mode Proportional Integral Derivative Control (SMC-PID). The output voltage and the inductor current of the applied control techniques are analyzed and compared in transient and steady state region. Also the robustness of the buck converter system is tested for load changes and input voltage variations. Matlab/Simulink is used for the simulations. The detailed simulation results are presented, which compare the performance of the designed controllers for various cases. The results show that the non linear control for DC/DC Buck converter proves to be more robust than linear control especially when dynamic tests are applied.

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ON DC TO AC CONVERSION IN A BOOST SELF-OSCILLATING STRUCTURE BASED ON NON-LINEAR CONTROL TECHNIQUES

IFAC Proceedings Volumes ◽

10.3182/20071017-3-br-2923.00047 ◽

2007 ◽

Vol 40 (20) ◽

pp. 280-285

Author(s):

Maurício S. Kaster ◽

Claudinor B. Nascimento ◽

Daniel J. Pagano

Keyword(s):

Linear Control ◽

Control Techniques ◽

Non Linear

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A Novel Non-Linear Control for Three-Phase Five-Level Cascaded H-Bridge Inverter Based Shunt Active Power Filter

International Journal of Emerging Electric Power Systems ◽

10.1515/ijeeps-2018-0052 ◽

2018 ◽

Vol 19 (5) ◽

Author(s):

Soumyadeep Ray ◽

Nitin Gupta ◽

Ram Avtar Gupta

Keyword(s):

Steady State ◽

Control Theory ◽

Dynamic Performance ◽

Active Power Filter ◽

Active Power ◽

Linear Control ◽

Shunt Active Power Filter ◽

Control Techniques ◽

Power Filter ◽

Non Linear

Abstract Cascaded H-Bridge multilevel inverter (CHB-MLI) based shunt active power filter (SAPF) provides a cost-worthy and realistic solution for mitigating current related power quality problems in case of medium-voltage and high-power grid. Mitigation of current harmonic component, reactive power minimization and power factor correction depend on accuracy of control technique applied to the CHB-MLI based SAPF unit. Switching technique dynamics is not considered by most of the researchers while designing control techniques applied to SAPF unit and hence it is assumed linear in order to make system simpler. A limited amount of literature is available which considers the non-linearity of CHB-MLI switching pattern while designing control theory for MLI based SAPF. Therefore, a novel non-linear control is proposed in this paper to enhance system steady-state and dynamic performance. This non-linear control is based on dynamic mathematical modeling of five-level CHB-MLI tied SAPF. Stability of proposed control strategy applied to CHB-MLI based SAPF is rigorously checked by using Lyapunov’s direct method. Proportional-Integral controller is used for stabilizing DC-link voltages to its proper reference value. This proposed control exhibits excellent dynamic performance and compensation criteria in comparison to conventional control techniques available in the literature. The effectiveness of the proposed control theory is tested rigorously in MATLAB/Simulink and verified through hardware prototype under steady-state and transient operating conditions. Rigorous analysis from hardware and simulation results confirms that source current waveform is in compliance with IEEE-519 standard defined THD limit.

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