Improved control strategy for power quality enhancement in standalone systems based on four‐leg voltage source inverters

Abstract

Standalone power supplies using renewable energy resources become a key solution to address both energy consumption and environmental restrictions in remote locations. These standalone systems are weak low-voltage networks, wherein the presence of heavy non-linear and/or unbalanced loads may adversely affect the output voltage quality. Accordingly, four-leg voltage-source inverters play an important role by providing both balanced and unbalanced loads with clean power and balanced output voltage. The reported work proposes a sliding mode control (SMC) along with an iterative learning control (ILC) for harmonic compensation in the presence of critical load conditions such as unbalanced non-linear loads. Indeed, under substantial disturbances, the ILC harmonic compensator smoothly adjusts the input control signal of the SM controller in such a manner to properly reject the disturbing harmonics. The design methodology of the proposed SMC-ILC control scheme is detailed and its effectiveness is validated through simulation and experimental results.

Power Quality and Capability Enhancement of a Wind-Solar-Battery Hybrid Power System

“…The second mode aims to enhance the HS power quality by reducing the fluctuations of the output power for different weather conditions. This objective aims to smooth the total power produced by the hybrid system in a way that is different from unlike other works which deal the subject of energy quality for the hybrid systems through other techniques and according to other concepts, such as: the technique that applies the improved control strategy for power quality enhancement in standalone systems based on four-leg voltage source inverters (presented in [13]), the technique that aims to achieve the power quality improvement of single phase weak grid interfaced hybrid solar PV and wind system using double fundamental signal extracter-based control (presented in [14]), the technique aims to improve the voltage of remote connection using wind-solar farms equipped with new voltage control strategy based on virtual impedance monitoring (presented in [15]) and the technique which aims to improve the energy quality using a shunt active power filter (presented in [16]).…”

Single‐stage high‐frequency‐isolated three‐phase four‐leg buck–boost inverter with unbalanced load

“…The predictive current control methods are proposed for the traditional three-phase four-leg inverter, quasi-Z-source four-leg inverter, and Z-source four-leg inverter separately by the authors of [13][14][15][16][17], which demonstrate excellent steady-state and transient response. An efficient control scheme based on the combination of a sliding mode controller with an iterative learning controller is proposed by Houari et al [18] for harmonics attenuation and power quality enhancement in a standalone system based on the four-leg inverter.…”

Robust three degrees of freedom based onH∞ controller of voltage/current loops for DG unit in micro grids

“…In [27], a hyper-plane multi-input multi-output (MIMO) sliding-mode controller (SMC) is studied using a nonlinear model of the converter to improve the stability and robustness of the closed-loop system. Houari et al [28] proposed an efficient control scheme for power quality in both current and voltage control loops based on the combination of a SMC with an iterative learning controller for harmonics attenuation. Zheng et al [29] propose an integral-type terminal sliding mode control.…”