New Double Closed Loop Linear Active Disturbance Rejection Control of Energy Storage Grid-Connected Inverter Based on Lead-Lag Correction Link

Youjie Ma,Xia Yang,Luyong Yang,Xuesong Zhou

doi:10.1109/access.2020.3000309

Youjie Ma, Xia Yang + Show 2 more

Open Access

https://doi.org/10.1109/access.2020.3000309

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Journal: IEEE Access	Publication Date: Jan 1, 2020
Citations: 21	License type: CC BY 4.0

Affiliation: Tianjin University of Technology

Abstract

The energy storage grid-connected inverter system is a complex system with strong nonlinearity and strong coupling, which quality and efficiency of grid-connection are affected by factors such as grid voltage fluctuations and model uncertainty. Based on the analysis of the working principle of the grid-connected energy storage system, this paper aims to improve the performance of the traditional linear active disturbance rejection control (LADRC) technology, in order to overcome the problems of serious phase lag of linear extended state observer (LESO) and poor ability to suppress high-frequency noise on the basis of introducing the proportional differential link in the traditional LESO, the differential term of output voltage error is introduced in LESO. In addition, the output of the channel for total disturbance is corrected to improve the disturbance observation ability of LESO against high-frequency noise. The theoretical proof of LADRC and the comparative analysis of Bode plots show that the improved LADRC has better anti-interference performance. Finally, to verify the effectiveness of the control strategy designed in this paper, different types of low-voltage ride-through faults are designed on the grid-side. The simulation results show that the new controller can improve the control performance effectively of the energy storage grid-connected system.

Highlights

Energy is the material basis for the survival and development of human society, and how to develop and utilize renewable energy reasonably is the embodiment of the degree of progress of human society
Improving linear extended state observer (LESO) is the core of linear active disturbance rejection control (LADRC), which tracking and estimation ability is the key to affect the performance of LADRC, so we first analyze it
In the improved LADRC design of voltage loop, udc is the input signal of LADRC, id is the control input, that is, the reference input iq−ref, udc and id of inner loop current can be obtained through measurement, so the improved LADRC combined with energy storage grid-connected inverter system can be designed as follows:

Summary

INTRODUCTION

Energy is the material basis for the survival and development of human society, and how to develop and utilize renewable energy reasonably is the embodiment of the degree of progress of human society. The energy storage inverter system adopts the voltage and current double loop control of proportional integral (PI) regulator generally, which has the advantages of simple control structure and easy to realize. Y. Ma et al.: New Double Closed Loop LADRC of Energy Storage Grid-Connected Inverter Based on Lead-Lag Correction Link does not depend on the precise mathematical model of the controlled object, and which simplifies the control system design greatly. The internal loop is a PI control strategy to control the current, which can realize the unit power factor control when the energy storage system operates stably and increase the reactive power output when the inverter works in static synchronous compensator (STATCOM) mode when the grid-side fails.

PARAMETER DESIGN OF TRADITIONAL FIRST-ORDER LADRC

PRINCIPLE ANALYSIS OF IMPROVED

CONVERGENCE ANALYSIS OF IMPROVED SECOND-ORDER LESO

SIMULATION ANALYSIS

Findings

CONCLUSIONS