Application of Repetitive Control in Electric Spring

Xi Zhang,Zheng Zheng

doi:10.1109/access.2020.3041648

Xi Zhang, Zheng Zheng

Open Access

https://doi.org/10.1109/access.2020.3041648

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Abstract

With the increasing of the grid-connected capacity of renewable energy such as wind energy and solar energy, its instability, intermittence and uncontrollability have a serious impact on the stable operation of power system, such as voltage fluctuation, frequency flicker, etc. Therefore, Electric Spring (ES) system has become a current research hotspot. Aiming at the deficiencies of the resonance control strategy, a control method that combines quasi-proportional resonance (QPR) control and repetitive control is proposed. The quasi proportional resonance control is used to realize the tracking without static error, and the internal model principle of repetitive control is used to suppress the periodic disturbance of the grid voltage, so as to improve the power quality of the grid. Compared with the traditional quasi proportional resonant control, the introduction of repetitive control can effectively improve the steady-state accuracy, reduce the system harmonic and enhance the ability of anti-harmonic interference. The modeling of ES and the design method of repetitive controller parameters are discussed in detail. The simulation model is built using MATLAB / Simulink, and the ES experimental platform is built with dSPACE as the control core, the results verify the feasibility and effectiveness of the proposed control strategy.

Highlights

Nowadays, there is a considerable amount of power contribution from renewable energy sources like wind and solar to meet our daily needs
PROPOSED CONTEOL STRATEGY OF THE Electric Spring (ES) Aiming at the above defects of quasi-proportional resonant (QPR) control harmonic compensation; this paper proposes that, on the basis of QPR control, a repetitive controller is introduced to eliminate harmonic interference of power grid
VS is the transient voltage of the critical load, VS-fb is the feedback voltage sensed from VS multiplied by a coefficient kvf (e.g., 1)

Summary

Introduction

There is a considerable amount of power contribution from renewable energy sources like wind and solar to meet our daily needs. With the increase of gridconnected capacity of renewable energy generation year by year, its instability, intermission and uncontrollable have brought serious impact on the stable operation of the power system, such as voltage fluctuation, harmonic pollution, frequency flicker, etc., resulting in the decline of power quality [1,2,3]. For those problems, Electric Spring (ES) system has become a current research hotspot. Cheng et al considered the disturbance of power grid voltage, proposed a control strategy combining quasi-proportional resonant (QPR) controller with power grid voltage feed-forward in [7] to VO LU ME XX, 2017

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Results

Conclusion