Fuzzy second order sliding mode control of a unified power flow controller

Purpose. This paper presents an advanced control scheme based on fuzzy logic and second order sliding mode of a unified power flow controller. This controller offers advantages in terms of static and dynamic operation of the power system such as the control law is synthesized using three types of controllers: proportional integral, and sliding mode controller and Fuzzy logic second order sliding mode controller. Their respective performances are compared in terms of reference tracking, sensitivity to perturbations and robustness. We have to study the problem of controlling power in electric system by UPFC. The simulation results show the effectiveness of the proposed method especiallyin chattering-free behavior, response to sudden load variations and robustness. All the simulations for the above work have been carried out using MATLAB / Simulink. Various simulations have given very satisfactory results and we have successfully improved the real and reactive power flows on a transmission lineas well as to regulate voltage at the bus where it is connected, the studies and illustrate the effectiveness and capability of UPFC in improving power.В настоящей статье представлена усовершенствованная схема управления, основанная на нечеткой логике и режиме скольжения второго порядка унифицированного контроллера потока мощности. Данный контроллер обладает преимуществами с точки зрения статической и динамической работы энергосистемы, например, закон управления синтезируется с использованием трех типов контроллеров: пропорционально-интегрального, контроллера скользящего режима и контроллера скользящего режима нечеткой логики второго порядка. Их соответствующие характеристики сравниваются с точки зрения отслеживания эталонов, чувствительности к возмущениям и надежности. Необходимо изучить проблему управления мощностью в энергосистеме с помощью унифицированного контроллера потока мощности (UPFC). Результаты моделирования показывают эффективность предложенного метода, особенно в отношении отсутствия вибрации, реакции на внезапные изменения нагрузки и устойчивости. Все расчеты для вышеуказанной работы были выполнены с использованием MATLAB/Simulink. Различные расчетные исследования дали весьма удовлетворительные результаты, и мы успешно улучшили потоки реальной и реактивной мощности на линии электропередачи, а также регулирование напряжения на шине, к которой она подключена, что позволяет изучить и проиллюстрировать эффективность и возможности UPFC для увеличения мощности

Optimal dynamic investment policies under concave-convex adjustment costs

Financing;Monopoly;Portfolio Management;management science

Mathematical Modeling of the Parabolic Trough Collector Field of the TCP-100 Research Plant

The 9th EUROSIM Congress on Modelling and Simulation, EUROSIM 2016 Oulu (Finlandia)There are two main drawbacks when operating solar energy systems: a) the resulting energy costs are not yet competitive and b) solar energy is not always available when needed. In order to improve the overall solar plants efficiency, advances control techniques play an important role. In order to develop efficient and robust control techniques, the use of accurate mathematical models is crucial. In this paper, the mathematical modeling of the new TCP100 parabolic trough collector (PTC) research facility at the Plataforma Solar de Almería is presented. Some simulations are shown to demonstrate the adequate behavior of the model compared to the facility design conditions.Junta de Andalucía P11-TEP-8129Unión Europea FP7-ICT-ICT-2013.3.4-611281Ministerio de Economía y Competitividadt DPI2014-56364-C2-2-

Variable Structure-Based Control for Dynamic Temperature Setpoint Regulation in Hospital Extreme Healthcare Zones

In critical healthcare units, such as operation theaters and intensive care units, healthcare workers require specific temperature environments at different stages of an operation, which depends upon the condition of the patient and the requirements of the surgical procedures. Therefore, the need for a dynamically controlled temperature environment and the availability of the required heating/cooling electric power is relatively more necessary for the provision of a better healthcare environment as compared to other commercial and residential buildings, where only comfortable room temperature is required. In order to establish a dynamic temperature zone, a setpoint regulator is required that can control the zone temperature with a fast dynamic response, little overshoot, and a low settling time. Thus, two zone temperature regulators have been proposed in this article, including double integral sliding mode control (DISMC) and integral terminal sliding mode control (ITSMC). A realistic scenario of a hospital operation theater is considered for evaluating their responses and performance to desired temperature setpoints. The performance analysis and superiority of the proposed controllers have been established by comparison with an already installed Johnson temperature controller (JTC) for various time spans and specific environmental conditions that require setpoints based on doctors’ and patients’ desires. The proposed controllers showed minimal overshoot and a fast settling response, making them ideal controllers for operation theater (OT) zone temperature control

Design of Sliding Mode PID Controller with Improved reaching laws for Nonlinear Systems

In this thesis, advanced design technique in sliding mode control (SMC) is presented with focus on PID (Proportional-Integral-Derivative) type Sliding surfaces based Sliding mode control with improved power rate exponential reaching law for Non-linear systems using Modified Particle Swarm Optimization (MPSO). To handle large non-linearities directly, sliding mode controller based on PID-type sliding surface has been designed in this work, where Integral term ensures fast finite convergence time. The controller parameter for various modified structures can be estimated using Modified PSO, which is used as an offline optimization technique. Various reaching law were implemented leading to the proposed improved exponential power rate reaching law, which also improves the finite convergence time. To implement the proposed algorithm, nonlinear mathematical model has to be decrypted without linearizing, and used for the simulation purposes. Their performance is studied using simulations to prove the proposed behavior. The problem of chattering has been overcome by using boundary method and also second order sliding mode method. PI-type sliding surface based second order sliding mode controller with PD surface based SMC compensation is also proposed and implemented. The proposed algorithms have been analyzed using Lyapunov stability criteria. The robustness of the method is provided using simulation results including disturbance and 10% variation in system parameters. Finally process control based hardware is implemented (conical tank system)

Intelligent Control of Switched Reluctance Motor for Electrical Vehicle Applications with Different Controller

تستخدم محركات المعاوقي المفتاحي لإنتاج الكثير من  عزم الدوران والتي تعمل عند التشبع المغناطيسي العالي. وبالنظر إلى التشبع المغناطيسي العالي، فإن العلاقة بين تيار الطور، وموقع الدوار هي علاقة غير خطية. لذلك فان  الضجيج، الاضطرابات، وعزم القصور الذاتي  عند  التحميل يمكن أن يكون لها جميعا تأثير سلبي على أداء المحرك المعاوقي المفتاحي. في هذه الدراسة تم تطوير وحدة التحكم الانزلاقي. وقد استخدم وحدة التحكم الانزلاقي في تنظيم السرع على مدى واسع  بما في ذلك المحرك المعاوقي المفتاحي في السرع العالية والسرع الواطئة وتقارن هذه الدراسة وحدة التحكم الانزلاقي مع وحدة التحكم التناسبي المتكامل التفاضلي في المحرك المعاوقي المفتاحي ذو 4/6 اقطاب باستعمال  الطرق الامثل للتحكم . ومقارنة  سرعة الجزء الدوار مع السرعة المضبوطة .فان وحدة التحكم الانزلاقي المتسارع هو الافضل من حيث الاداء والمتانة في  تطبيق السيارات الكهربائية  تبعا لنظام السيمولنك المستخدم Switched reluctance motors (SRM) are used to produce a lot of torque when they are operating at high magnetic saturation. Due to the high magnetic saturation, the relationship between phase current, rotor position, and the flux linkage of SRM is nonlinear. Noise, disturbances, and inertia of load torque can all have a negative impact on the SRM driver system's speed controller performance. In this study, the SRM driver system's sliding mode controller was developed .The sliding mode controller( SMC) speed controller was used to regulate speeds of the SRM throughout a wide range speeds, including high and low speeds. This study compares (SMC) with a modified reaching law and a Proportional Integral Divertive Control (PID) controller for a 6/4 pole SRM using an optimization technique for switching controllers. Furthermore, the rotor speed was simulated and compared to the reference speed. The Exponential Sliding Mode Controller (ExpSMC) is the best in terms of performance and robustness for an electric vehicle application, depending on a simulation of an established test bench using the two controllers

Sliding Mode Control

The main objective of this monograph is to present a broad range of well worked out, recent application studies as well as theoretical contributions in the field of sliding mode control system analysis and design. The contributions presented here include new theoretical developments as well as successful applications of variable structure controllers primarily in the field of power electronics, electric drives and motion steering systems. They enrich the current state of the art, and motivate and encourage new ideas and solutions in the sliding mode control area

On the Stability of Direct Spring-Operated Pressure Relief Valves: Impact of Frozen Mixture Flow and Lift Restriction

The current work explores the effect of (frozen) mixture flow and lift restriction on the stability of direct spring-operated pressure relief valves. First, we study the effect of frozen mixture (constant mass fraction) flow through a pressure relief valve with upstream piping. DIER\u27s $\omega$ technique is employed to cope with the mixture parameters, notably sonic velocity and choked/non-choked flow through the nozzle. By means of one-dimensional simulation, we show that the change in sonic velocity plays a fundamental role in both the valve opening time and its stability. Due to the extremely low sonic velocities in certain range of water-air mass fraction, such valves will have a poor response time (slow opening) and chatter even for short inlet pipings. Next, we investigate the possibility of improving the dynamical performance of the safety valve by using a larger valve (i.e., a larger orifice) with a restricted lift option while keeping the vented mass flow rate through the valve constant. Our numerical investigations reveal that the additional restoring force emerging from the valve restriction at the upper stopper improves the stability behaviour in the case of gas applications but can hardly have any influence in the case of liquid service

A measure theoretic approach to traffic flow optimization on networks

We consider a class of optimal control problems for measure-valued nonlinear transport equations describing traffic flow problems on networks. The objective isto minimise/maximise macroscopic quantities, such as traffic volume or average speed,controlling few agents, for example smart traffic lights and automated cars. The measuretheoretic approach allows to study in a same setting local and nonlocal drivers interactionsand to consider the control variables as additional measures interacting with the driversdistribution. We also propose a gradient descent adjoint-based optimization method, ob-tained by deriving first-order optimality conditions for the control problem, and we providesome numerical experiments in the case of smart traffic lights for a 2-1 junction.Comment: 20 pages, 6 figure