scholarly journals An enhanced exponential reaching law based sliding mode control strategy for a three phase ups system

2020 ◽  
Vol 17 (3) ◽  
pp. 313-336
Author(s):  
Venkatesh Nayak ◽  
Satish Gudey
Keyword(s):  
Steady State ◽  
Sliding Mode Control ◽  
Frequency Response ◽  
Sliding Mode ◽  
Higher Order ◽  
System Stability ◽  
Reaching Law ◽  
Three Phase ◽  
Sinusoidal Waveform ◽  
Exponential Reaching Law

UPS is used to deliver a high quality sinusoidal waveform to consumers without any interruptions. This work proposes an Enhanced Exponential Reaching Law (EERL) based Sliding Mode Control (SMC) for a three- phase UPS 30 kVA system used in industrial Applications. The work presents the application of proposed controller on the rectifier side as well as on the inverter side feeding a linear and/or a nonlinear load. Mathematical models of the three phase rectifier (AC/DC) and three phase inverter (DC/AC) are derived. Frequency response characteristics are plotted to observe the system stability using state feedback approach. A DC/DC buck/boost converter is utilised for charging and discharging of battery which acts as a secondary power source for the UPS to feed critical loads. It also maintains power balance. The design of SMC, HOSMC and EERL-SMC are presented. The EERL based SMC is used in this work to obtain a pure sinusoidal waveform with less settling time compared to a conventional SMC. It is robust against sudden changes in load and is more efficient compared to SMC and higher order sliding mode controller (HOSMC). Using EERL, chattering phenomenon can be very much reduced with less steady state error. Chattering is observed through phase plane plots in this paper. The system is presented with both linear and nonlinear loads. A comparison is brought with respect to a classical SMC and a higher order SMC (super twisting algorithm) for a UPS system. EERL-SMC performs better in terms of pure sinusoidal waveform, good tracking, less settling time (4ms) and less steady state error (1.74%) with low THD (0.12%). It can be an alternative to a HOSMC. Simulation studies are presented in PSCAD/EMTDC version 4.6. The system stability conditions are analysed from frequency response plots obtained through MATLR2012b platform.

scholarly journals Sliding Mode Control of DFIG Wind Turbines with a Fast Exponential Reaching Law

Energies ◽  
2017 ◽  
Vol 10 (11) ◽  
pp. 1788 ◽  
Author(s):  
Linyun Xiong ◽  
Penghan Li ◽  
Hao Li ◽  
Jie Wang
Keyword(s):  
Sliding Mode Control ◽  
Wind Turbines ◽  
Sliding Mode ◽  
Reaching Law ◽  
Mode Control ◽  
Exponential Reaching Law

Application of the Sliding Mode Control Approach Based on Double Power Exponential Reaching Law for the Hydraulic Servo System

2015 ◽  
Vol 741 ◽  
pp. 655-658 ◽  
Author(s):  
Cai Yun Dong ◽  
Hai Jun Wang ◽  
Wen Yong Cui
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Servo System ◽  
Mathematic Model ◽  
Control Approach ◽  
Reaching Law ◽  
Mode Control ◽  
Hydraulic Servo ◽  
Hydraulic Servo System ◽  
Exponential Reaching Law

The sliding mode control approach based on double power exponential reaching law is proposed for the hydraulic servo system. With the example of the hydraulic servo system in the lab, the mathematic model is established and the new controller is presented and simulated. Simulation results show that: the proposed approach has high track precision, fast response, small chattering and ensures dynamic quality of the system.

Sliding Mode Control of Magnetic Bearing System Based on Variable Rate Reaching Law

2011 ◽  
Vol 460-461 ◽  
pp. 827-830 ◽  
Author(s):  
Jing Feng Mao ◽  
Ai Hua Wu ◽  
Guo Qing Wu ◽  
Xu Dong Zhang
Keyword(s):  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Magnetic Bearing ◽  
System Stability ◽  
Control Law ◽  
Variable Rate ◽  
Reaching Law ◽  
Mode Control ◽  
Bearing System

In order to eliminate the chattering phenomena caused by conventional sliding mode control (SMC) method in magnetic bearing system control, this paper proposes a variable rate reaching law approach based sliding mode controller to achieve higher system stability and robustness. In this control law, system states’ normal numbers are brought in to automatic adjust the gain of the switching control part of SMC. The controller output amplitude of chattering can be progressively damped, and the system will converge to zero asymptotically. The system stability is proved by Laypunov theory, and the prerequisite of control law parameters design is deduced out. Simulation results show that the proposed SMC control method has effectiveness in dynamic suspension position tracking performance and obtaining system robustness.

scholarly journals Nonsingular Terminal Sliding Mode Control of PMSM Based on Improved Exponential Reaching Law

Electronics ◽  
2021 ◽  
Vol 10 (15) ◽  
pp. 1776
Author(s):  
Changhong Jiang ◽  
Qiming Wang ◽  
Zonghao Li ◽  
Niaona Zhang ◽  
Haitao Ding
Keyword(s):  
Sliding Mode Control ◽  
Permanent Magnet ◽  
Sliding Mode ◽  
Permanent Magnet Synchronous Motor ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Reaching Law ◽  
Mode Control ◽  
Nonsingular Terminal Sliding Mode ◽  
Exponential Reaching Law

When a permanent magnet synchronous motor runs at low speed, the inverter will output discontinuous current and generate torque ripple; when the motor is runs at high speed, a large amount of stator harmonic current generates, which affects its speed following ability and torque stability. To ensure the fast and smooth switching of a permanent magnet synchronous motor in the full speed domain, this paper proposes the nonsingular terminal sliding mode control of PMSM speed control based on the improved exponential reaching law. Firstly, the improved exponential reaching law is composed of the state variables and power terms of the sliding mode surface functions. The reaching law function is designed in sections to balance the fast dynamic response of the system and chattering control. Secondly, an improved exponential reaching law based on the sliding mode control strategy of the PMSM speed loop is proposed. By designing the initial value of the integral term in the nonsingular terminal sliding mode surface function, the initial state of the system is located on the sliding mode surface. The integral sliding mode surface is used to reduce the system steady-state error, while the proposed sliding mode reaching law is used to increase the arrival speed and suppress system chattering, ultimately affecting modeling error problems, complex working conditions, and uncertainty factors. This paper proposes a sliding mode observer based on an improved exponential reaching law to compensate for the disturbances. Lyapunov stability theory can prove that this system can make the speed tracking error converge to zero in finite time. Hardware-in-the-loop experiments were used to validate the effectiveness of the proposed method.

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