Next Article in Journal
Power-Balancing Based Induction Machine Model for Power System Dynamic Analysis in Electromechanical Timescale
Next Article in Special Issue
Remote Power Control Injection of Grid-Connected Power Converters Based on Virtual Flux
Previous Article in Journal
A Fully Three Dimensional Semianalytical Model for Shale Gas Reservoirs with Hydraulic Fractures
Previous Article in Special Issue
Solar Energy Potentials and Benefits in the Gulf Cooperation Council Countries: A Review of Substantial Issues
Article Menu
Issue 2 (February) cover image

Export Article

Open AccessArticle
Energies 2018, 11(2), 437; https://doi.org/10.3390/en11020437

A Systematic Controller Design for a Grid-Connected Inverter with LCL Filter Using a Discrete-Time Integral State Feedback Control and State Observer

Department of Electrical and Information Engineering, Seoul National University of Science and Technology, 232 Gongneung-ro, Nowon-gu, Seoul 01811, Korea
*
Author to whom correspondence should be addressed.
Received: 16 January 2018 / Revised: 2 February 2018 / Accepted: 11 February 2018 / Published: 16 February 2018
(This article belongs to the Special Issue Sustainable and Renewable Energy Systems)
Full-Text   |   PDF [9626 KB, uploaded 22 February 2018]   |  

Abstract

Inductive-capacitive-inductive (LCL)-type filters are currently preferred as a replacement for L-type filters in distributed generation (DG) power systems, due to their superior harmonic attenuation capability. However, the third-order dynamics introduced by LCL filters pose a challenge to design a satisfactory controller for such a system. Conventionally, an LCL-filtered grid-connected inverter can be effectively controlled by using a full-state feedback control. However, this control approach requires the measurement of all system state variables, which brings about more complexity for the inverter system. To address this issue, this paper presents a systematic procedure to design an observer-based integral state feedback control for a LCL-filtered grid-connected inverter in the discrete-time domain. The proposed control scheme consists of an integral state feedback controller and a full-state observer which uses the control input, grid-side currents, and grid voltages to predict all the system state variables. Therefore, only the grid-side current sensors and grid voltage sensors are required to implement the proposed control scheme. Due to the discrete-time integrator incorporated in the state feedback controller, the proposed control scheme ensures both the reference tracking and disturbance rejection performance of the inverter system in a practical and simple way. As a result, superior control performance can be achieved by using the reduced number of sensors, which significantly reduces the cost and complexity of the LCL-filtered grid-connected inverter system in DG applications. To verify the practical usefulness of the proposed control scheme, a 2 kW three-phase prototype grid-connected inverter has been constructed, and the proposed control system has been implemented based on 32-bit floating-point digital signal processor (DSP) TMS320F28335. The effectiveness of the proposed scheme is demonstrated through the comprehensive simulation and experimental results. View Full-Text
Keywords: discrete-time model; DSP TMS320F28335; grid-connected inverter; integral state feedback control; LCL filter; state observer discrete-time model; DSP TMS320F28335; grid-connected inverter; integral state feedback control; LCL filter; state observer
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Yoon, S.-J.; Lai, N.B.; Kim, K.-H. A Systematic Controller Design for a Grid-Connected Inverter with LCL Filter Using a Discrete-Time Integral State Feedback Control and State Observer. Energies 2018, 11, 437.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Energies EISSN 1996-1073 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top