TY - JOUR
T1 - Disturbance-Observer-Based Control for Dual-Stage Grid-Tied Photovoltaic System under Unbalanced Grid Voltages
AU - Errouissi, Rachid
AU - Al-Durra, Ahmed
N1 - Funding Information:
Manuscript received July 13, 2018; revised October 3, 2018; accepted October 27, 2018. Date of publication November 13, 2018; date of current version June 28, 2019. This work was supported by the Advanced Power and Energy Center, APEC, Khalifa University, Abu Dhabi, UAE. (Corresponding author: Ahmed Al-Durra.) The authors are with the Electrical & Computer Engineering Department at Khalifa University, Sas Al-Nakhl Campus, P.O. Box 2533, Abu Dhabi, United Arab Emirates (e-mail:, rachid.errouissi@hotmail.fr; ahmed.aldurra@ku.ac.ae).
Funding Information:
This work was supported by the Advanced Power and Energy Center, APEC, Khalifa University, Abu Dhabi, UAE
Publisher Copyright:
© 1982-2012 IEEE.
PY - 2019/11
Y1 - 2019/11
N2 - This paper presents the design and experimental validation of disturbance observer (DO)-based control for grid-tied photovoltaic (PV) inverters fed by a dc-dc boost converter considering unbalanced grid voltages. The control scheme uses multiples controllers that are developed based on employing DO technique along with a feedback-linearizing (FBL) control. The main controller is designed to regulate the active and reactive powers injected into the grid via controlling the grid-tied inverter. Under unbalanced grid voltages, the active and reactive power is composed of a dc component as well as an ac component that oscillates at twice the grid frequency. Therefore, the unknown perturbation, representing the mismatch between the nominal and actual system, can be treated as a sum of a constant offset and a sinusoidal disturbance. To ensure accurate control of the active/reactive power, a DO is designed to estimate the unknown perturbation, which is then canceled by a FBL control. By considering the control input limitation in the observer synthesis, an antiwindup compensator arises naturally in the control law, which attenuates the effect of the windup phenomenon during control saturation. Moreover, a simplified representation of the DO is proposed to facilitate real-time implementation. The proposed approach for the power control can be used in both balanced and unbalanced systems since it can reject constant and sinusoidal disturbances. Experimental tests were performed to investigate the ability of the proposed control scheme to achieve good transient and steady-state performances.
AB - This paper presents the design and experimental validation of disturbance observer (DO)-based control for grid-tied photovoltaic (PV) inverters fed by a dc-dc boost converter considering unbalanced grid voltages. The control scheme uses multiples controllers that are developed based on employing DO technique along with a feedback-linearizing (FBL) control. The main controller is designed to regulate the active and reactive powers injected into the grid via controlling the grid-tied inverter. Under unbalanced grid voltages, the active and reactive power is composed of a dc component as well as an ac component that oscillates at twice the grid frequency. Therefore, the unknown perturbation, representing the mismatch between the nominal and actual system, can be treated as a sum of a constant offset and a sinusoidal disturbance. To ensure accurate control of the active/reactive power, a DO is designed to estimate the unknown perturbation, which is then canceled by a FBL control. By considering the control input limitation in the observer synthesis, an antiwindup compensator arises naturally in the control law, which attenuates the effect of the windup phenomenon during control saturation. Moreover, a simplified representation of the DO is proposed to facilitate real-time implementation. The proposed approach for the power control can be used in both balanced and unbalanced systems since it can reject constant and sinusoidal disturbances. Experimental tests were performed to investigate the ability of the proposed control scheme to achieve good transient and steady-state performances.
KW - Antiwindup scheme
KW - Disturbance observer (DO)
KW - Grid-tied inverter
KW - Low-voltage ride through (LVRT)
KW - Nominal performance recovery
KW - Photovoltaic (PV) system
KW - Sinusoidal disturbance rejection
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U2 - 10.1109/TIE.2018.2880141
DO - 10.1109/TIE.2018.2880141
M3 - Article
AN - SCOPUS:85056583883
SN - 0278-0046
VL - 66
SP - 8925
EP - 8936
JO - IEEE Transactions on Industrial Electronics
JF - IEEE Transactions on Industrial Electronics
IS - 11
M1 - 8533618
ER -