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This paper presents a sliding mode controller for a wound rotor synchronous machine, acting as a generator for an isolated load. The standard dq-model of the machine is connected to a resistive load. A sliding surface is defined in order to fulfill control objectives, and the Ideal Sliding Dynamics is proved to be stable. From the desired surface, the standard sliding methodology is applied, and a...
The present work deals with the classical problem of speed estimation for a small 4 rotors helicopter drone based on acceleration, rotation angles and angular speed measurements only. This problem concerns indoors applications as well as outdoors applications close-by large structures. Small Unmanned Air Vehicles (UAV) are commonly used for inspection applications such as beneath bridges, water dams,...
High performance operation of speed controlled AC drives without mechanical speed/position sensors rely on the dynamic models for estimation of flux and speed. Using backstepping, which is a recursive nonlinear design method, a new approach for the design of observers for speed sensorless control is developed. The resulting scheme leads to a nonlinear full order observer for the rotor field. The rotor...
In this paper a Lyapunov control algorithm for a small scale autonomous model helicopter is obtained using robust backstepping techniques. The controller design does not consider the small body forces. The proposed controller is based on dynamic order reduction for the nonlinear dynamical model. Some simulation results are presented to illustrate the performance of such controller in the presence...
The goal of this paper is the analysis of the dynamic behavior of a multi-phase asynchronous motor. The Power-Oriented Graphs technique has been used for modeling the system and a very simple and compact model has been obtained. The steady-state equations of the system have been studied finding remarkable relations between the motor voltage and current vectors. The eigenvalues of the electrical part...
A small helicopter can be considered as a test bench of a highly nonlinear unstable multiconnected mechanical control system. An automatic stabilization system was designed on a standard computer for a small electrical helicopter. The sensor device consists of two Web cameras connected to the computer and four onboard diodes. The control signal is transmitted to actuators through a wireless control...
Considering the rotating engine speed control problem, speed sensors of measurement output are replaced by an event-detection scheme or simply an imprecise and low-resolution encoder. This results in considerable measurement simplification and cost reductions. Modeling the integrated plant-detector system will result in a nonlinear discrete-time model with a sample time dependent on state vector....
In this paper, we consider the problem of computing the steady state solutions of a model of an helicopter, in the particular case in which the center of mass is subject to vertical oscillations. We present preliminary studies of a complete design of an internal model-based controller to achieve automatic smooth landing of helicopters on an oscillating platform. We model the reference signal as the...
The paper considers the problems of designing self-tuning output voltage regulators for standalone wind power plants equipped with asynchronized synchronous generators. Variations in wind speed and load (such as connection and disconnection of electric customers) result in variable output voltage and frequency of a windmill. Using an asynchronized synchronous generator allows one to fairly easily...
Spiral wave drifting and meandering are known measures for cardiac instability and arrhythmogenesis. This study was aimed to analyze spiral wave drifting due to temperature heterogeneity that is applied artificially. Our hypothesis is that spatial temperature gradients (STGs) will cause spatial excitability heterogeneity, which in turn will affect the spiral waves' dynamics. This may help to detect,...
Switched reluctance machines with its uncomplicated structure, low cost, high reliability and fault tolerance, is struggling to gain higher market share almost in all electric machinery utilities. Its simplicity encouraged researchers to apply a wide variety of classic and intelligent control techniques. These techniques are used to control the speed and torque via appropriate determination of switching-on...
Wound Rotor Induction Machine (WRIM) is used in various motoring and generating applications. Control of this machine from rotor side improves the operating speed and reduces the rating as well as cost of converter. The method proposed in this paper is field oriented control of WRIM with single current sensor. Rotor reference currents of current controllers are used for estimating the un-sensed rotor...
This paper describes a generalized method to develop steady state model (SSM) of different electric motors comprising electric equivalent circuit (EEC) and the torque equation. In most of the books on electric motors, EEC is used to explain operation and performance characteristics of motors, but the development of these EECs is not explained convincingly. This work overcomes this shortcoming by specifically...
Elevator systems have become an essential part of the current urban society. This paper tries to minimize the losses in an elevator system, thereby increasing the overall system efficiency. The system considered in this paper uses induction machine to drive the elevator. The losses in induction machine are dependent on the rotor speed so, they are minimized by optimizing the instantaneous values of...
This work presents a standstill (offline) parameter identification method for synchronous machines with dual field excitation on the d and q axes of the rotor. Such machines have applications as turbogenerators and synchronous motors. One machine with an equivalent model is the divided winding rotor synchronous generator, which is a round rotor machine that was proposed by Soper and Fagg. A methodology...
This work presents an computational tool of unbalanced voltage supply detection on-line in induction motor. A technique based on Goertzel algorithm has been used to compute the desired component frequency for real time application. The computer algorithm has been implemented in a low cost microcontroller (Arduino). Two successful methods have been used for condition monitoring of induction motors;...
Voltage stability issue is a key problem which attracting worldwide attention because voltage stability may leads to voltage collapse. This paper investigates the impact of Squirrel Cage induction generator (SCIG) and Doubly Fed Induction Generator (DFIG) on the power system small signal stability. Here considered wind generators are SCIG which is fixed speed and DFIG is variable speed. Small signal...
This paper presents the nonlinear control for variable speed wind turbine (VSWT). The dynamics of the wind turbine (WT) are derived from the single mass model. The control objective is to maximize the energy capture from the wind with reduced oscillation on the drive train. The generator torque is considered as the control input and it depends on the optimal rotor speed which is derived from the effective...
In this paper, a multi-variable nonlinear control of a twin rotor aerodynamical system (TRAS) is presented. A control-oriented state-space model with four states is derived employing Lagrange's equations. Using this system representation, a multi-variable flatness-based control is designed for an accurate trajectory tracking concerning both the pitch angle characterising the vertical motion and the...
In this paper, is proposed a robust sensorless speed observer-controller scheme for a Permanent Magnet Synchronous Motor (PMSM) based on the use of an Extended Kalman Filter (EKF) to estimate both position and speed, without any mechanical sensor. Then, a state-feedback optimal control algorithm is developed for uncertain of PMSM, based on the use of an Algebraic Riccati Equation (ARE) and a convex...
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