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Under the single-loop structure, the problem of overcurrent protection for permanent magnet synchronous motor (PMSM) is investigated in this paper. Due to the combination of speed loop and current loop, the q-axis current become a state of PMSM control system, instead of the output of current loop in the cascade control. As a consequence, the conventional controllers can not restrict the q-axis current into a safe zone. But an oversize transient current may lead to damage of hardwares and property loss. To this end, a new current-constrained controller is proposed to deal with the issue of over-current protection. Different from previous methods of state constraints, the effects of disturbance is taken into account of controller design. A reduced-order generalized proportional integral observer (RGPIO) is adopted to estimate the uncertainties and disturbances. Our method can be considered as a composition of current-constrained control plus feed-forward compensation based on RGPIO. A rigorous stability analysis for the closed-loop system is presented. Compared with the conventional PID controller, the proposed method not only limits q-axis current to a safe range, but also has a good anti-disturbance ability. The feasibility and efficiency of the proposed method is validated by both simulation and experimental results. [ABSTRACT FROM AUTHOR]

• Absolute threshold ETM and relative case are constructed for control input by using tanh function. • A complex adaptive compensation scheme is developed to estimate the unknown bounds of mismatched uncertainties, disturbances and cyberattacks. • The integral term is introduced in the controller to reduce triggering times caused by data jitters. This paper is concerned with the event-triggered security adaptive control of uncertain multi-area power systems. Adaptive laws are presented to estimate the unknown bounds of uncertainties, disturbances and cyber-attacks. With the help of tanh function, two event-triggered mechanisms are proposed in terms of integral state feedback controllers and adaptive controllers. With the help of Simpson rule and the Lyapunov stability theory, sufficient conditions are built in terms of linear matrix inequalities to ensure the mean-square boundedness of the resultant closed-loop systems. Finally, the validity of proposed schemes is verified by a simulation. [ABSTRACT FROM AUTHOR]

In order to optimize the control performance of the compliant actuator system, a generalized predictive control (GPC) method is introduced in the controller design. Compared with conventional predictive control methods which largely depend on the modeling, the proposed GPC method is almost model-free. The stability of closed-loop system has been rigidly proved. Various experimental tests of a series elastic actuator driven exoskeleton robot are verified the effectiveness of the proposed methods. [ABSTRACT FROM AUTHOR]