Vector control

An estimated 40 % of the population in Benin lives in urban areas. The purpose of the study was to estimate malaria endemicity and the fraction of malaria-attributable fevers in health facilities in Cotonou. A health care system evaluation and a series of school parasitaemia surveys and health facility-based surveys were carried out during the dry season in of 2003, applying standard Rapid Urban Malaria Appraisal (RUMA) methodology. This study was part of a multi-site assessment supported by the Roll Back Malaria Partnership. The field work was carried out in February-March 2003. In 2002 and out of 289,342 consultations in the public health facilities of Cotonou there were 100,257 reported simple malaria cases (34.6%) and 12,195 complicated malaria cases (4.2%). In the school parasitaemia surveys, a malaria infection was found in 5.2 % of all samples. The prevalence rates of parasitaemia in the centre, intermediate and periphery zones were 2.6%, 9.0% and 2.5%, respectively. In the h...

© 2003 Dadzie et al; licensee BioMed Central Ltd. This is an Open Access article: verbatim copying and redistribution of this article are permitted in all media for any purpose, provided this notice is preserved along with the article's original URL. Sixty-four experts from a variety of disciplines attended a Conference on the Eradicability of Onchocerciasis at The

Today, malaria prevention hinges upon two domestic interventions: insecticide-
treated bed nets and indoor residual spraying. As mosquitoes grow resistant to
these tools, however, novel approaches to vector control have become a priority
area of malaria research and development. Spatial repellency, a volumetric mode
of action that seeks to reduce disease transmission by creating an atmosphere
inimical to mosquitoes, represents one way forward. Drawing from research that sought to develop new repellent chemicals in conversation with users from sub-
Saharan Africa and the United States, we consider the implications of a non-insecticidal paradigm of vector control for how we understand the political ecology of malaria.

— Switched reluctance motor is an electric motor which possesses advantageous features that qualifies it to be used in electric vehicle and aerospace application. There are various drivers have been previously and actively being used to drive the switched reluctance motor. In this paper, the switched reluctance motor is controlled utilizing vector control using fuzzy logic controller and ANN controller in order to minimize the torque ripple by regulating torque within specified hysteresis band. Both fuzzy logic and ANN Control of Switched Reluctance Motor fed through an asymmetrical converter. Both of controllers are simulated in MATLAB/ SIMULINK for fixed SRM parameters. According to the obtained results the switched reluctance motor is performing very well when driven by fuzzy logic controller in comparison to the ANN controller.

The high-speed operation region of interior permanent magnet (PM)(IPM) motor drives is investigated, with particular attention to the maximum-torque-per-voltage operation. A technique is proposed for the control of the drive in such region, based on direct-flux field-oriented vector control. The proposed control is easy to implement, does not require the accurate knowledge of the motor model, and showed to be robust toward the effects of iron losses, position estimation errors, and dc-link variations. Moreover, it is suitable for ...

In this paper, fractional order PI (FOPI) control is developed for speed control of permanent magnet synchronous motor (PMSM). Designing the parameters for FOPI controller is a challenging task, especially for nonlinear systems like PMSM. All three PI controllers in the conventional vector controlled speed drive are replaced by FOPI controllers. Design of these FOPI controllers is based on the locally linearized model of PMSM around an operating point. This operating point changes with the load torque. The novelty of the work reported here is in use of Non Linear Disturbance Observer (NLDO) to estimate load torque to obtain this new operating point. All three FOPI controllers are then designed adaptively using this new operating point. The scheme is tested on simulation using MATLAB/SIMULINK and results are presented.

The present research study is focused on the design, development and validation of a device based on multilevel converter for medium voltage distribution networks. It regulates the reactive power exchanged with the grid (up to 3 MVAR), allowing to achieve the following objectives: Network voltage regulation, reactive power compensation and power factor control. The device is composed by an IGBT based 4 level NPC (neutral point clamped) converter. The adopted modulation strategy is the space vector modulation and it takes into account the bus capacitor voltage balancing. The reactive power regulation will be carried out by a vector control technique. The correct behavior of the electronic system connected to a radial distribution network is validated in simulation. Firstly the behavior of the system is analyzed under normal operation conditions. After that, its robustness is analyzed when sudden network voltage changes occur

In this work the design and construction of a control system is presented, its main objective is to achieve the smooth connection of a doubly fed induction generator (DFIG) with the electrical grid. The presented system emulates a wind energy conversion system (WECS), typically called wind turbine. The aforementioned system is formed by two minor subsystems: the first one is a control system that regulates the voltage of a dc bus, the second one is the generator controlled by a three phase power converter.
Two digital signal processors (DSP) were used for, acquiring and processing the signals an also for executing the needed computations for the control algorithms. For controlling both subsystems, the vector control technique is used, with a reference frame oriented to the grid voltage vector. The estimation of the amplitude, frequency and angle parameters for the grid voltage is done with a phase locked loop (PLL), these information is crucial for the synchronization process of the electrical machine with the grid. The connection of the generator must be done only if the amplitude, frequency, and phase of the stator voltage is equal to that of the grid voltage. Otherwise, when the connection occurs, high transient currents up to 500 % of the rated current will flow in the stator.
A detailed mathematical analysis and modeling of the system is presented, and allowed to develop vector control estructures based in the linear PI controller. An scale sized prototype was developed to carry out experiments for the synchronization and connection. Connection experiments were carried out with the stator voltage synchronized and not synchronized with the grid, the obtained results are coherent with the ones predicted by the theoretical analysis. The experimental results demonstrated the need of the synchronization for achieving a secure connection of the generator. The operation of the system in the generation mode was not addressed here, and is proposed to be experimented in a future work.

Induction machines are widely used in various applications including industrial applications and locomotive applications. The electric systems used in industrial applications are required to have higher performance and reliability requirement so three phase induction motors are preferable because they are simple to design, easy to maintain and are less costly.
However, induction motors do not have capability of variable speed operation, it is in that reason, the speed control of induction motor has become essential. This report deals with the investigation, experimental tests and compares the main concept of speed control of induction motor using V/F control method and vector control method with the help of AC2 - Space Vector PWM VSI Induction 3HP Motor Drive Simulink model.
Variable voltage and frequency (V/F control) method is the most suitable common method of speed control for the applications without position control requirements for high accuracy of speed control but V/F control is inferior to vector control for complex dynamic behavior of the induction motor so the vector control technique works with vector quantities, controlling the desired values by using space phasors which is a better solution so that the control on flux and torque become independent from each other and the induction motor is transformed from a non-linear to linear control plant.
In this report many experiments were investigated though the build in Simulink model did not allow any changes of some parameters, so the two methods of speed control of induction machine were not clearly investigated but it compares the main concepts of the two methods of controlling speed of induction motor.

The aim of this thesis is to develop a sensorless control strategy for an oscillating linear
permanent magnet synchronous motor.
The state-of-the-art sensorless methods are examined and their reliability to linear drives
is discussed. Subsequently, an adaptive sliding mode concept is chosen to estimate the
position of the mover. In the next step, the concept is implemented and simulated in
Matlab-Simulink. The results are discussed in detail.
Finally, the concept is implemented in the rapid-prototyping software X2C and evaluated
on the real plant. The results conrm the functionality of the concept for an oscillating
operation of the linear motor. The attainable accuracy of the stroke control is veried
with different levels of load. The limitations of the use of the investigated concept are shown.

The paper focuses on the reconfiguration process of vector control systems of the induction motor supplied from the tandem (hybrid) static-frequency converter. Reconfigurable control structure ensures different strategies for operating modes with non-failed and partial-failed converter. The reconfiguration process introduces perturbations in the vector controlled AC drives. The paper analyses the perturbation effects of the control system reconfiguration and presents

O motor elétrico proporcionou largos passos no processo de desenvolvimento da humanidade, substituindo o homem no desempenho de tarefas repetitivas e de
intenso esforço. Dentre eles, o motor de indução trifásico possui construção robusta e elevado rendimento, apresentando-se como um dos mais versáteis tipos de motores.
Porém, possui a desvantagem de um complexo sistema de controle de velocidade, pouco comum em baixa potência. O desenvolvimento de um inversor que exerça o
controle da velocidade para essa faixa de motores é o assunto deste trabalho, baseado no controle escalar em malha fechada de velocidade, operando adequadamente embarcado em uma plataforma de desenvolvimento e um hardware construído.

Today, the whole world faces a great challenge to overcome the environmental problems related to global energy production. Most of the islands throughout the world depend on fossil fuel importation with respect to energy production. Recent development and research on green energy sources can assure sustainable power supply for the islands. But unpredictable nature and high dependency on weather conditions are the main limitations of renewable energy sources. To overcome this drawback, different renewable sources and converters need to be integrated with each other. This paper proposes a standalone hybrid photovoltaic- (PV-) wave energy conversion system with energy storage. In the proposed hybrid system, control of the bidirectional buck-boost DC-DC converter (BBDC) is used to maintain the constant dc-link voltage. It also accumulates the excess hybrid power in the battery bank and supplies this power to the system load during the shortage of hybrid power. A three-phase complex vector control scheme voltage source inverter (VSI) is used to control the load side voltage in terms of the frequency and voltage amplitude. Based on the simulation results obtained from Matlab/Simulink, it has been found that the overall hybrid framework is capable of working under the variable weather and load conditions. © 2014 Nahidul Hoque Samrat et al.

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