Load frequency control scheme for a microgrid system with the application of hTLO-DE algorithm

Load frequency control (LFC) is a crucial feature of electric power systems to maintain a balance between power supply and load demand, thus avoiding a deviation of the grid frequency. The present work aims to implement an effective LFC scheme for a microgrid system consisting of a diesel generator (DEG), a wind turbine generator (WTG) and a battery storage system. Proportional-integral-double-derivative (PIDD) controllers are used to implement the proposed LFC scheme. The controller parameters are computed using an innovative hybrid teaching-learning-optimization differential-evaluation (hTLO-DE) algorithm. The main scope of the work lies in application of hTLO-DE optimized PIDD controllers in DEG-WTG-battery storage based MG system. The results obtained with PIDD controllers are compared with those obtained with the traditional PI and PID controllers. A critical analysis shows that the PIDD controller can provide better dynamic responses in terms of settling time and magnitude of oscillations compared to PI and PID controllers. The frequency responses of the system are studied under different scenarios of generation and load variations, which establishes the robustness of the proposed PIDD-based LFC scheme

Medicinal uses and pharmacological properties of Moringa oleifera

Moringa oleifera Lam [Moringaceae] is a highly valued plant, distributed in many countries of the tropics and subtropics. It has an impressive range of medicinal uses with high nutritional value. Different parts of this plant contain a profile of important minerals, and are a good source of protein, vitamins, β -carotene, aminoacids and various phenolics. In addition to its compelling water purifying powers and high nutritional value, M. oleifera is very important for its medicinal value. Various parts of this plant such as the leaves, roots, seed, bark, fruit, flowers and immature pods act as cardiac and circulatory stimulants, possess anitumor, antipyretic, antiepileptic, antiinflammatory, antiulcer, antispasmodic, diuretic, antihypertensive, cholesterol lowering, antioxidant, antidiabetic, hepatoprotective, antibacterial and antifungal activities, and are being employed for the treatment of different ailments in the indigenous system of medicine. This review focuses on the detailed phytochemical composition, medicinal uses, along with pharmacological properties of different parts of this multipurpose tree.Keywords: Moringa oleifera; β –carotene; anitumo

Design of Novel Fly-Back Converter Using PID Controller

ABSTRACT: Fly-back converters have been widely used because of the irrelative simplicity and their excellent performance for multi output applications. They can save cost and volume compared with the other converters, especially in moderate low power applications..In a fly-back converter, a transformer is adopted to achieve galvanic isolation and energy storage. Modelling is done without parasitic as well as with parasitic components. A detailed analysis, simulation and different control strategy are conferred for Fly-back converter. To verify the design and modelling at primary stage, study of the converter in for input AC voltage220V at 50Hz and output DC voltage of 440V and 150W output power rating. I.INTRODUCTION Fly-back converter is the most commonly used SMPS circuit for low output power applications where the output voltage needs to be isolated from the input main supply. The output power of fly-back type SMPS circuits may vary from few watts to less than 100 watts. The overall circuit topology of this converter is considerably simpler than other SMPS circuits. Input to the circuit is generally unregulated dc voltage obtained by rectifying the utility ac voltage followed by a simple capacitor filter. The circuit can offer single or multiple isolated output voltages and can operate over wide range of input voltage variation. In respect of energy-efficiency, fly-back power supplies are inferior to many other SMPS circuits but it's simple topology and low cost makes it popular in low output power range. The commonly used fly-back converter requires a single controllable switch like, MOSFET and the usual switching frequency is in the range of 100 kHz. A two-switch topology exists that offers better energy efficiency and less voltage stress across the switches but costs more and the circuit complexity also increases slightly. Parameters such as switching frequency, distortion, losses, harmonic generation and speed of response are typical of the issues which must be considered when developing modulation strategies for a particular family of converters .The DC converter is a device which transforms AC to DC i

Comparative morpho-micrometric analysis of some Bauhinia species (Leguminosae) from east coast region of Odisha, India

Bauhinia vahlii has been reported for several medicinal properties, such as tyrosinase inhibitory, immunomodulatory and free radical scavenging activities. Bauhinia tomentosa and Bauhinia racemosa also possess anti-diabetic, anticancer, antidiabetic, anti-obesity and antihyperlipidemic activities. Therefore, the correct identification of these plants is critically important. The aim was to investigate the comparative morpho-micrometric analysis of 3 species of Bauhinia belonging to the family Leguminosae (Fabaceae) by using conventional as well as scanning electron microscopy to support species identification. In B. racemosa, epidermal cells are polygonal with anticlinical walls; whereas wavy walled cells are found in B. tomentosa and B. vahlii. Anisocytic stomata are present in B. racemosa, while B. tomentosa shows the presence of paracytic stomata and anomocytic stomata in B. vahlii. Stomatal numbers and stomatal indices were found to be more in B. vahlii than B. tomentosa and B. racemosa. On the other hand, uniseriate, unicellular covering trichomes are found in B. racemosa and B. tomentosa but B. vahlii contains only uniseriate, multicellular covering trichomes. Based on these micromorphological features, a diagnostic key was developed for identification of the particular species which helps a lot in pharmaceutical botany, taxonomy and horticulture, in terms of species identification

Comparative morpho-micrometric analysis of some Bauhinia species (Leguminosae) from east coast region of Odisha, India

169-184Bauhinia vahlii has been reported for several medicinal properties, such as tyrosinase inhibitory, immunomodulatory and free radical scavenging activities. Bauhinia tomentosa and Bauhinia racemosa also possess anti-diabetic, anticancer, antidiabetic, anti-obesity and antihyperlipidemic activities. Therefore, the correct identification of these plants is critically important. The aim was to investigate the comparative morpho-micrometric analysis of 3 species of Bauhinia belonging to the family Leguminosae (Fabaceae) by using conventional as well as scanning electron microscopy to support species identification. In B. racemosa, epidermal cells are polygonal with anticlinical walls; whereas wavy walled cells are found in B. tomentosa and B. vahlii. Anisocytic stomata are present in B. racemosa, while B. tomentosa shows the presence of paracytic stomata and anomocytic stomata in B. vahlii. Stomatal numbers and stomatal indices were found to be more in B. vahlii than B. tomentosa and B. racemosa. On the other hand, uniseriate, unicellular covering trichomes are found in B. racemosa and B. tomentosa but B. vahlii contains only uniseriate, multicellular covering trichomes. Based on these micromorphological features, a diagnostic key was developed for identification of the particular species which helps a lot in pharmaceutical botany, taxonomy and horticulture, in terms of species identification

Comparative Study between Conventional PID and Fuzzy Logic Controller for a Current Controlled D.C. Drive Using MATLAB/Simulink

ABSTRACT: This paper describes a closed loop model of a current controlled PMDC motor drive with two controller FUZZY & PID separately, then comparison of the effect on output parameters for this two different controller is established. The differences between the output speed of PMDC motor & a preset reference speed is fed as an error signal to the controller of the system. The output of the speed controller (actuating signal) controls the duty cycle of converter and hence controls the converter output. Through this controlled converter output, required voltage gets injected into the motor. A small change in the injected voltage can cause a large change in the motor current and hence leading to a particular drive control feature. In the past few years Fuzzy Logic became a very much popular choice of controller for feedback control of various industrial systems. Fuzzy logic control is much closer in spirit to human thinking and logical reasoning than conventional controller like PID or PI. Recent study shows that this type of controller (FUZZY) provides better settling time, low peak overshoot and less percent of steady state error in overall system output which leads to better stability of overall system. In this Paper, a performance analysis of the conventional PID controller and fuzzy logic controller has been done by the use of MATLAB. . Depending on the armature voltage control method simulink model of a current mode buck-type dc chopper-fed permanent-magnet (PM) dc motor drive with proportional controller in its feedback loop is realized [3][4] . But the importance of PID controllers in process industry cannot be overemphasized because although some modern controllers like FUZZY got popularity, the majority of the industrial controllers use PID or modified PID control schemes KEYWORDS

Nonlinear Dynamics of a Current Controlled D.C. Drive with PID Controller

ABSTRACT: This paper describes a closed loop model of a current controlled PMDC motor drive with PID Controller. The output speed of the PMDC motor is compared with a preset reference speed. The differences between these two signals are fed as an error signal to the PID controller of the system. The output of the speed controller is the actuating signal that controls the duty cycle of converter and hence controls the converter output. Through this controlled converter output, required voltage gets injected into the motor to bring it back to its desired speed. As a small change in the input voltage can cause a large change in the motor current and lead to a particular drive control feature. I. RELATED WORK PM motor drives have been a topic of interest for the last twenty years. Different authors have carried out modeling and simulation of such drives. The three most common speed control methods of a dc motor are field resistance control, armature voltage control, and armature resistance control II. INTRODUCTION Developments of high performance motor drives are very essential for industrial applications. A high performance motor drive system must have good dynamic speed command tracking and load regulating response. DC motors provide excellent control of speed for acceleration and deceleration and chopper fed permanent magnet PMDC motor allows precise voltage control, which is necessary for speed and torque control applications. DC drives, because of their simplicity, ease of application, reliability and favourable cost have long been a backbone of industrial applications. DC drives are less complex as compared to AC drives system. DC drives are normally less expensive for low horsepower ratings. DC motors have a long tradition of being used as adjustable speed machines and a wide range of options have evolved for this purpose. Cooling blowers and inlet air flanges provide cooling air for a wide speed range at constant torque. PMDC motors are conveniently portable and well fit to special applications, like industrial equipments and machineries that are not easily run from remote power sources. PMDC motor is considered a SISO (Single Input and Single Output) system having torque/speed characteristics compatible with most mechanical loads. This makes a PMDC motor controllable over a wide range of speeds by proper adjustment of the terminal voltage using various innovative design and control technique

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Not Availablehe article reviews three decades of ICAR-Central Institute of Freshwater Aquaculture’s contributions towards empowering women through aquaculture. It chronicles the projects that had been operated by the Institute with a special focus on women. A host of technologies – carp seed rearing, grow-out culture, value addition, etc. were promoted to ensure the livelihood and economic security of rural women. Factors impeding women’s involvement in aquaculture and related enterprises are identified. The authors argue that linking the stakeholders with credit, technology, training, and the market has to be built into the project to ensure the significant and valuable contribution of women towards the blue revolution.Not Availabl