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1

Improved STATCOM efficiency using a hybrid technique based on sliding mode control and proportional integral control

Belila Hassen

Przegląd Elektrotechniczny

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2020

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R. 96, nr 10

156--162

EN

Static compensators of reactive power (STATCOMs) are among the most efficient devices for improving the network power quality. The efficiency of such devices is largely determined by the used automatic control technique. In this work, we propose an advanced hybrid algorithm based on Sliding Mode Control (SMC) combined with classical proportional-Integral (PI) technique. To show the efficiency of the proposed method, a comparison with the traditional PI control is performed. The comparison focused mainly on dynamic performance and grid harmonic pollution.

PL

Jakość działania kompensatora mocy biernej STATCOM zależy od właściwości układu automatycznego sterowania. W pracy zaprezentowano hybrydowy algorytm bazujący na sterowaniu ślizgowym współpracujący z klasycznym sterownikiem PI.

2

Global path planning for multiple AUVs using GWO

Panda Madhusmita, Das Bikramaditya, Pati Bibhuti

Archives of Control Sciences

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2020

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Vol. 30, No. 1

77--100

EN

In global path planning (GPP), an autonomous underwater vehicle (AUV) tracks a predefined path. The main objective of GPP is to generate a collision free sub-optimal path with minimum path cost. The path is defined as a set of segments, passing through selected nodes known as waypoints. For smooth planar motion, the path cost is a function of the path length, the threat cost and the cost of diving. Path length is the total distance travelled from start to end point, threat cost is the penalty of collision with the obstacle and cost of diving is the energy expanse for diving deeper in ocean. This paper addresses the GPP problem for multiple AUVs in formation. Here, Grey Wolf Optimization (GWO) algorithm is used to find the suboptimal path for multiple AUVs in formation. The results obtained are compared to the results of applying Genetic Algorithm (GA) to the same problem. GA concept is simple to understand, easy to implement and supports multi-objective optimization. It is robust to local minima and have wide applications in various fields of science, engineering and commerce. Hence, GA is used for this comparative study. The performance analysis is based on computational time, length of the path generated and the total path cost. The resultant path obtained using GWO is found to be better than GA in terms of path cost and processing time. Thus, GWO is used as the GPP algorithm for three AUVs in formation. The formation follows leader-follower topography. A sliding mode controller (SMC) is developed to minimize the tracking error based on local information while maintaining formation, as mild communication exists. The stability of the sliding surface is verified by Lyapunov stability analysis. With proper path planning, the path cost can be minimized as AUVs can reach their target in less time with less energy expanses. Thus, lower path cost leads to less expensive underwater missions.

3

Model Predictive Super-twisting sliding mode control for an autonomous surface vehicle

Esfahani Hossein Nejatbakhsh, Szlapczynski Rafal

Polish Maritime Research

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2019

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nr 3

163--171

EN

This paper presents a new robust Model Predictive Control (MPC) algorithm for trajectory tracking of an Autonomous Surface Vehicle (ASV) in presence of the time-varying external disturbances including winds, waves and ocean currents as well as dynamical uncertainties. For fulfilling the robustness property, a sliding mode control-based procedure for designing of MPC and a super-twisting term are adopted. The MPC algorithm has been known as an effective approach for the implementation simplicity and its fast dynamic response. The proposed hybrid controller has been implemented in MATLAB / Simulink environment. The results for the combined Model Predictive Super-Twisting Sliding Mode Control (MP-STSMC) algorithm have shown that it significantly outperforms conventional MPC algorithm in terms of the transient response, robustness and steady state response and presents an effective chattering attenuation in comparison with the Super-Twisting Sliding Mode Control (STSMC) algorithm.