An Improved Sliding Mode Control Technique to Mitigate Mismatched Parameter Uncertainties of Three-Phase Voltage Source Inverters

Abstract

This paper proposes a theoretical and experimental implementation of an advanced sliding mode control (SMC) for a three-phase voltage source inverter (VSI) to achieve robustness against the unknown uncertainties of an LC filter. The significant contributions of the proposed SMC are summarized as considerations for the matched and mismatched uncertainties of the LC filter, more relaxed normbounds, dynamic characterization of sliding surface, and unique stability analysis. Unlike the conventional SMC techniques with matched uncertainties, the mismatched uncertainties in the state matrix are taken for the design of the proposed SMC. Also, the relaxed norm-bound designed for matched and mismatched uncertainties allows a wide range of variations in the values of LC filter. The voltage tracking errors are significantly reduced and the total harmonic distortions (THDs) are highly suppressed by characterizing the sliding surface in terms of flexible linear matrix inequalities (LMIs). Next, the stability analysis and reachability conditions are given using the Lyapunov criterion. The authenticity of the proposed SMC method is proved by TMS320LF28335 DSP based experimental results with a prototype 1-kVA test-bed. The comparative experimental results and analysis for the proposed SMC scheme, the conventional SMC scheme, and the conventional PI−PI control scheme are presented under the load step change, unbalanced load, and non-linear load step change with the parameter uncertainties to demonstrate the excellent performance of the proposed controller such as fast transient response, small steady-state error, and low THD.INDEX TERMS Parameter uncertainties, sliding mode control (SMC), three-phase voltage source inverter (VSI), total harmonic distortion (THD).

Comparative Study of Passivity, Model Predictive, and Passivity-Based Model Predictive Controllers in Uninterruptible Power Supply Applications

“…UPS is used to power loads, like personal computers, industrial automated equipment, and communication equipment. Controlled VSI is expected to have low harmonics [1], excellent ability to reject disturbances, and robustness to parameter mismatch [2].…”

Robust Optimal Tracking Control of a Full-Bridge DC-AC Converter

“…Currently, sliding mode control (SMC) has been well recognized that the assurance of insensitive trajectory can be achieved under model parameter variations and exogenous perturbations [21][22][23][24][25]. The application of SMC has been developed to handle many significant non-linear systems [26][27][28][29][30]. Thanks to the intellectualized SMC scheme, a low-priced microcontroller has been proposed to mitigate the trembling, but the load suffers from steady errors when dealing with abrupt intermissions [31].…”