Adaptive Integral Second-Order Sliding Mode Control Design for Load Frequency Control of Large-Scale Power System with Communication Delays

Anh-Tuan Tran,Van-Duc Phan,Tam Minh Nguyen,Bui Le Ngoc Minh,Viet-Thanh Pham,Van Van Huynh,Phong Thanh Tran,Rui Wang

doi:10.1155/2021/5564184

Abstract

Nowadays, the power systems are getting more and more complicated because of the delays introduced by the communication networks. The existence of the delays usually leads to the degradation and/or instability of power system performance. On account of this point, the traditional load frequency control (LFC) approach for power system sketches a destabilizing impact and an unacceptable system performance. Therefore, this paper proposes a new LFC based on adaptive integral second-order sliding mode control (AISOSMC) approach for the large-scale power system with communication delays (LSPSwCD). First, a new linear matrix inequality is derived to ensure the stability of whole power systems using Lyapunov stability theory. Second, an AISOSMC law is designed to ensure the finite time reachability of the system states. To the best of our knowledge, this is the first time the AISOSMC is designed for LFC of the LSPSwCD. In addition, the report of testing results presents that the suggested LFC based on AISOSMC can not only decrease effectively the frequency variation but also make successfully less in mount of power oscillation/fluctuation in tie-line exchange.

Highlights

In modern power networks, the frequency stability is one of the significant problems related to the large-scale power system (LSPS) with communication delays. e system has been more and more complicated for load frequency control (LFC) due to matched or mismatched uncertainties, load variations, and time-delays [1,2,3,4]
The time-delay can appear in the state variables or in the input channel of LSPS. e input control signal is transported to the power plants through communication networks with delay time. e state delay-time is the essential reason to effect on delaying the basic elements of communication or transportation in the LSPS. e deviation of tie-line exchange power and frequency are combined and known as an area control error (ACE) to confirm the control frequency aim for the LSPS. e balance in both the tie-line and frequency exchange power is assured when an ACE is controlled and limited
To the best of our knowledge, the adaptive integral second-order sliding mode control (AISOSMC) scheme has not been developed for LFC problem in the large-scale power system with communication delays (LSPSwCD) so far. e major contributions of this paper are displayed as follows: e novel theory based on AISOSMC approach is offered for the LSPSwCD

Summary

Introduction

The frequency stability is one of the significant problems related to the large-scale power system (LSPS) with communication delays. e system has been more and more complicated for LFC due to matched or mismatched uncertainties, load variations, and time-delays [1,2,3,4]. The performance of LSPS using control scheme given in [20,21,22,23,24,25,26,27] is achieved without considering the time-delay in the power grids. In order to solve this problem, the control scheme given in [28,29,30] is proposed to regulate the frequency deviation of the LSPS in the presence of communication delays and sudden load change.

Results

Conclusion