Adaptive suboptimal second-order sliding mode control for microgrids

Abstract

International Journal of Control ASSOSM˙Microgrids˙manuscriptThis paper deals with the design of adaptive suboptimal second order sliding mode (ASSOSM) control laws for grid-connected microgrids. Due to the presence of the inverter, of unpredicted load changes, of switching among different renewable energy sources, and of electrical parameters variations, the microgrid model is usually affected by uncertain terms which are bounded, but with unknown upper bounds. To theoretically frame the control problem, the class of second order systems in Brunovsky canonical form, characterized by the presence of matched uncertain terms with unknown bounds, is first considered. Four adaptive strategies are designed, analyzed and compared to select the most effective ones to be applied to the microgrid case study. In the first two strategies the control amplitude is continuously adjusted, so as to arrive at dominating the effect of the uncertainty on the controlled system. When a suitable control amplitude is attained, the origin of the state-space of the auxiliary system becomes attractive.In the other two strategies a suitable blend between two components, one mainly working during the reaching phase, the other being the predominant one in a vicinity of the sliding manifold, is generated, so as to reduce the control amplitude in steady-state. The microgrid system in grid-connected operation mode, controlled via the selected ASSOSM control strategies, exhibits appreciable stability properties, as proved theoretically and shown in simulation.

Distributed Second Order Sliding Modes for Optimal Load Frequency Control

“…. , n, cannot be a-priori estimated, the adaptive version of the SSOSM algorithm proposed in [23] can be used in order to dominate the effect of the uncertainties.…”

Cyber-physical cooperative control strategy for islanded micro-grid considering communication interruption

“…And it has been also widely applied in micro-grid. 29 So to improve the control effect on output voltages and frequency by droop control of DERs under communication interruption, a cyber-physical cooperative control strategy is proposed in this paper. There are cyber and physical layers in the control structure.…”

“…Among the control strategies above, the SMC has the best ability to resist the outer disturbances. And it has been also widely applied in micro‐grid …”

Second order sliding mode control for nonlinear affine systems with quantized uncertainty

“…Because of the continuous nature of the control action, HOSM control approaches are appropriate to be applied even to electrical, electromechanical or mechanical systems [11,12], as testified by [13][14][15][16][17][18][19][20].…”