Event-driven fuzzy L∞ control of DC microgrids under cyber attacks and quantization

This paper investigates the event-driven fuzzy <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="script">L</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>∞</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> control of direct-current (DC) microgrids subject to deception attacks, persistent bounded (PB) disturbances, premise mismatching, quantizer, and delays. First, using states of the fuzzy plant and a constant, a Zeno-free dynamic event-triggered mechanism (ETM) is presented, which is more robust to the PB disturbances than the static state-related ETMs (SSRETMs). Second, by virtually dividing the updating intervals of the controller, a unified time-delay fuzzy system model is established, which takes effects of dynamic ETM, deception attacks, disturbances, quantizer, and delays into account. Third, criteria for globally exponentially ultimately bounded (GEUB) stability in mean square with guaranteed <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi mathvariant="script">L</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>∞</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> -gain are obtained, and the quantitative relationship between the ultimate bound and the dynamic ETM is established. To overcome the inconvenience of the emulation method requiring two design steps, a co-design strategy is provided to simultaneously design the ETM and fuzzy controller subject to premise mismatching. Simulation results confirm that, even with the triggering rate 36.9% and the attacking rate 11.4%, satisfactory control performance can still be achieved; the dynamic ETM achieves better triggering performance than the SSRETMs; and the proposed controller achieves shorter settling time and smaller overshoot than the robust linear controller.