Continuous finite‐time control of four‐leg inverter through fast terminal sliding mode control

Abstract

Summary A favorable option to supply unbalanced loads and provide the neutral wire is the four‐leg inverter. Controllers with high robustness and dynamic response should be used to adjust the inverter load voltages for unknown, unbalanced, and nonlinear loads. Sliding mode controls (SMCs) have a simple structure, good robustness against model parameter uncertainties, and desirable transient response. However, chattering phenomena, variable switching frequency, and error convergence to the operating point on infinite time are the main weaknesses of the conventional SMC method. In this paper, to restrict the conversion time to a finite and controllable value, terminal sliding mode control (TSMC) and fast terminal sliding mode control (FTSMC) procedures are proposed to regulate the load voltages of the four‐leg inverter. In these methods, a continuous control output is suggested to fix the switching frequency and reduce chattering phenomena significantly. Furthermore, the proposed methods are highly robust against model parameter uncertainties. Different simulation and experimental results on a 3‐kW test bench under different loading conditions are done to validate the significant performance of the proposed methods.

Dual‐sliding mode control of nine‐switch inverter

“…From ( 11) and ( 12), it can be concluded that x 2 equals to d(x 1 )/dt. The sliding surface is expressed in (13).…”

Extended state observer-based nonsingular terminal sliding mode controller for a DC-DC buck converter with disturbances: theoretical analysis and experimental verification

“…Non-singular terminal sliding-mode control (NTSMC) approach with a nonlinear sliding surface has been adopted for high requirement on a DC-DC buck converter (Pichan et al, 2020;Yang et al 2013;. In this method, the time taken to reach the desired set point from any initial states under the disturbances is guaranteed to be a finite time, so output voltage in DC-DC buck converter will reach the desired voltage within time required.…”

Simultaneous voltage unbalance compensation and neutral‐to‐ground voltage minimization for an islanded mini‐grid using model predictive control

“…The use of inverter-based DGs is one of the best solutions to compensate for the above-mentioned issues, because they can easily cope with unbalanced networks. Several types of inverter topologies are introduced to provide a neutral wire in islanded mini-grids that are presented extensively in the literature [2,[7][8][9]. The three-phase four-leg voltage source inverter (VSI) is the best topology for providing the neutral wire due to the proper operation to supply balanced output voltages even under severe unbalanced load conditions.…”