One main contribution of this dissertation is to analyze the stability characteristics of extended state observer (ESO) and active disturbance rejection control (ADRC). In particular, asymptotic stability of the dynamic system that describes the estimation error and the closed-loop system is established where the plant dynamics is completely known. In the face of large dynamic uncertainties, th...

Inverter-based standalone power systems (ISPSs), with limited inertia/damping, are prone to significant changes in frequency indicators encompassing deviation and rate of change (RoCoF), which can easily exceed the pertinent relay thresholds cause outages. Limited by estimating disturbance system inertia/damping deficiency, existing controls cannot ensure stability. To overcome this issue, a tr...

This paper addresses an approximation-based anti-windup (AW) control strategy for suppressing the windup effect caused by actuator saturation nonlinearity in proportional–integral–derivative (PID) controlled systems. The effect of actuator constraint is firstly regarded as a disturbance imported to the PID controller. The external disturbance can then be modeled by a linear differential equatio...

non-fragile observer design is the main problem of this paper. using continuous frequency distribution, the stability conditions based on integer order lyapunov theorem are derived for lipschitz class of nonlinear fractional order systems. the proposed observer is stable beside the existence of both gain perturbation and input disturbance. for the first time, in this paper a systematic method i...

One of the general trends in power industry is penetration distributed generation (DG) units. The ongoing transformation electric systems (EPS) due to this leads a significant change properties systems. problem arises ensuring stability distribution system with DG units and EPS as whole, especially case large disturbances. main way solving positive-sequence phasor time-domain simulation. Howeve...

In this paper, stability and disturbance attenuation issues for a class of Networked Control Systems (NCSs) under uncertain access delay and packet dropout effects are considered. Our aim is to find conditions on the delay and packet dropout rate, under which the system stability and H ∞ disturbance attenuation properties are preserved to a desired level. The basic idea in this paper is to form...

In this paper, stability and disturbance attenuation issues for a class of Networked Control Systems (NCSs) under uncertain access delay and packet dropout effects are considered. Our aim is to find conditions on the delay and packet dropout rate, under which the system stability and H∞ disturbance attenuation properties are preserved to a desired level. The basic idea in this paper is to formu...

Disturbance Observer based robot control algorithms provide good performance while giving a straightforward method of gain selection. Unfortunately, the stability of these algorithms has not been shown rigorously for nonlinear systems such as robots. This paper demonstrates that a disturbance observer based algorithm can be made equivalent to the well known passivity based approaches of Sadegh ...

In the past, rock slope stability analysis were performed either graphically or using a hand-held calculator, but nowadays there are variety of slope stability analysis which can be used according to the field condition and potential failure mode. In 2-D analysis, effect of convex and concave walls are neglected, however concave slopes are believed to be more stable than straight walls due to t...