The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Stability margins of the switch-mode DC/DC power conversion systems are very sensitive to variations in load and system parameters. In aerospace applications these systems can be exposed to considerable variations in temperature that can cause large changes in system parameters from their nominal values and can lead to stability problems if this issue is not properly taken into account during the...
This paper proposes a controller design method using modeling-error feedback to improve steady-state performance for a system with time delay. The controller is designed based on the mixed H2/H∞ control assuring the stability condition with Lyapunov-Krasovskii functional. The proposed method resolves the problem of steady-state error due to model error which the conventional method using a communication...
Most existing networked filtering methods are proposed to solve the filtering problem under single (wireless or wired) network environment. However, with the development of the networked technology, hybrid networks that integrate wireless and wired networks are gradually employed in industrial fields. The main objectiveness of the paper is to investigate H2/H∞ filtering of hybrid networks with random...
Dead-times are widely utilized for the inverters to prevent short-circuits. In motor drive applications, 6th-order torque pulsations caused by dead-times depend on rotational speeds of motors. A Disturbance OBserver (DOB) approach is effective for the dead-time compensation in low load operations. The performance of the DOB depends on the observer gains. Hence, if we use the conventional constant...
Visual and auditory communication over the Internet has enabled communication unlike any humankind has experienced before. However, Internet communication based on haptic interfaces is not yet widespread. This study seeks to allow thousands of people to share the sense of force and enjoy Internet games such as tug-of-war by providing a stabilizing system able to overcome Internet communication delay...
The Cuk converter is a non-isolated DC-DC converter having fourth-order and non-linear dynamic characteristics. In this paper, an output feedback controller is proposed for the regulation of the negative output Cuk converter. The main advantage of the proposed controller is only the output voltage state variable is used for feedback purposes. This eliminates the use of the current sensor. Various...
This paper is concerned with the event-triggered finite-time control scheme for unicycle robots. First, Lagrange method is used to model the unicycle robot at the roll and pitch axis. Second, on the basis of the established model, an event-triggered finite-time control scheme is proposed to balance the unicycle robot in finite time and to determine whether or not control input should be updated. The...
In this paper a simple sliding mode controller based on the averaging state space model is proposed for a DC-DC boost converter. It is demonstrated to be easily implemented and has time-variant sliding coefficients. The proposed controller can effectively regulate the output voltage by controlling the switch states (through the dynamic duty cycles) even when the input voltage, load or output command...
Gyroscopically manipulated lateral motion of a single-wheel based robot system has a parametric oscillation problem. In this paper, we analyze the stability regions for balancing the single-wheel robot system and then propose how to determine the offset range of its suppression controller. Since the roll motion is coupled with the pitch motion, the parametric oscillation problem should be analyzed...
The sustainable energy based generation systems, such as photovoltaic and wind turbine generation systems, normally adopt inverters to connect to the grid. These power electronics interfaces possess characteristics of small inertia and small output impedance, which create difficulties to stabilize the voltage and frequency of a distributed micro power source. To deal with this problem, this paper...
In an autonomous microgrid without connection to the interconnected grid to support the frequency and voltage, it is more complex to control and manage. Thus in order to investigate the dynamic stability of the medium-voltage (MV) microgrid in Dongao Island, a detailed small-signal state-space model of the autonomous MV mixed-source microgrid containing diesel generator set (DGS), grid-supporting...
This paper aims to discuss the H∞ control problem of nonlinear stochastic switched systems in case where both global asymptotically stable in the mean (GASiM) subsystems and unstable subsystems coexist. An average dwell time (ADT) scheme is established to show us that the system is GASiM, if the activation time of GASiM subsystems is comparatively longer than that of unstable ones. Further, some conditions...
This paper presents an eigenvalue-based harmonic stability analysis method for inverter-fed power systems. A full-order small-signal model for a droop-controlled Distributed Generation (DG) inverter is built first, including the time delay of digital control system, inner current and voltage control loops, and outer droop-based power control loop. Based on the inverter model, an overall small-signal...
This paper presents a novel terminal sliding mode (TSM) control scheme with double closed-loop structure of capacitor voltage and inductance current for the stability control of DC-DC buck converter. In order to satisfy the different performance demands of capacitor voltage and inductance current, a TSM controller and a linear sliding mode (LSM) controller is designed separately. For the former, TSM...
Stability and accuracy of PHIL simulation depends upon the characteristics of the interface between the RTS and the hardware device under test. Even when stable PHIL is achieved, the non-idealities in the PHIL interface introduces inaccuracies in the simulation results. Software models that include representation of the PHIL interface provide a method to evaluate the stability and accuracy of a PHIL...
This paper presents a novel two channel control law for high transparency teleoperation under time delay with guaranteed delay independent L2 stability. Four channel controllers have long been known to provide transparent teleoperation when time delay does not exist on the communication channels. However under time delay, a trade-off between delay and transparency must be made to make the system stable...
This work investigates current control of an isolated bidirectional Phase-Shifted (PS) Dual Active Bridge (DAB) DC-DC converter (270V/28V, 5kW), for an energy storage application based on a 28V Li-Ion Battery. Two control strategies are investigated. First, a nonlinear average-model-based Sliding Mode Controller (SMC) is developed. Then, a model-less Fuzzy Control (FC) is presented and proven to be...
In this paper, an exact fuzzy modeling is adapted to design a nonlinear controller/observer for an inverted pendulum on a cart. Based on computed torque method, the nonlinear model is simplified, and two scalar valued auxiliary functions are defined and used to construct a full fuzzy model. Based on the obtained model, efficient and more practical controller and observer are designed with less complexity...
This paper includes the development and validation of a dynamic model suitable for control design and stability analysis of a HVDC diode-based rectifier grid connection for offshore wind power plants. The modular design of the model allows for a relatively easy extension to different grid topologies and control strategies. The developed models include the effects of communication delays and a non-stationary...
In this paper, an enhanced power sharing strategy employing adaptive virtual impedances for Q-ω and P-V droop-based islanded microgrids (MGs) is proposed. The proposed scheme improves the performance of dynamic response and system stability while accurate power sharing is obtained. The low-bandwidth communication is utilized to send the power commands. The adaptive virtual impedances consist of a...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.