Aiming to solve the tracking control problem of a class of second-order underactuated mechanical systems with unknown model parts, external disturbances and noise disturbances, a double closed-loop layered integral terminal sliding mode control method based on sliding mode observer is proposed. At the outset, the Lagrange model of the system is transformed into an affine model, and a sliding mode observer is designed according to the system structure. Neatly, the outer loop controller is designed using the observer’s estimated state, and the output value of the outer loop controller is filtered with a low pass filter. Then the inner loop controller is designed by using hierarchical sliding mode control method. On a premise of ensuring tracking performance, the control method can maximally improve convergence speed and reduce chattering even if there are unknown model parts, external interference and noise interference phenomena in the system. This simulation results distinctly display the effectiveness of the control tactics.

Double Closed-loop Integral Terminal Sliding Mode for a Class of Underactuated Systems Based on Sliding Mode Observer

Some modified Hestenes-Stiefel conjugate gradient algorithms with application in image restoration

Reinforcement-learning-based dynamic defense strategy of multistage game against dynamic load altering attack

This paper presents a robust protection scheme to protect the power transmission network against a class of feedback-based attacks referred in the literature as "Dynamic Load Altering Attacks" (D-LAAs). The proposed scheme envisages the usage of Energy Storage Systems (ESSs) to avoid the destabilising effects that a malicious state feedback has on the power network generators. The methodologies utilised are based on results from polytopic uncertain systems, invariance theory and Lyapunov arguments. Numerical simulations on a test scenario validate the proposed approach.

/pdf/ensuring-the-stability-of-power-systems-against-dynamic-load-w6y8lrjn92.pdf

Ensuring the Stability of Power Systems Against Dynamic Load Altering Attacks: A Robust Control Scheme Using Energy Storage Systems

A coordinated adaptive feedback linearization controller (FLC-A) based on a flux observer for DC-based DFIG to track the maximum power point (MPP) is introduced in this paper. The stator and rotor of DFIG are connected to DC grid directly by two voltage source converters. First, an adaptive controller is used to track the MPP on the system which is decoupled by a single-loop feedback linearization strategy. Meanwhile, the proposed controller can estimate and compensate the changes of stator and rotor resistances caused by physical environment in real time, and improve the dynamic performance of the system; second, under the persistent excitation condition (PED), a stator flux observer with online resistance estimation in the stationary reference frame is adopted to replace the traditional flux calculation method or flux meter, which increases system reliability. The stability of adaptive control rate and nonlinear observer is proved by Lyapunov theory. Simulations are carried out to prove the effectiveness and robustness of the proposed control strategy.

MPPT Adaptive Controller of DC-based DFIG in Resistances Uncertainty

In this paper a power system protection scheme based on energy storage system placement against closed-loop dynamic load altering attacks is proposed. The protection design consists in formulating a non-convex optimization problem, subject to a Lyapunov stability constraint and solved using a two-step iterative procedure. Simulation results confirm the effectiveness of the approach and the potential relevance of using energy storage systems in support of primary frequency regulation services.

/pdf/on-the-optimization-of-energy-storage-system-placement-for-2wul15g0ny.pdf

Antonio Rabezzano

Papers

On the optimization of energy storage system placement for protecting power transmission grids against dynamic load altering attacks