Andres Olarte

PMU-based line and transformer parameter estimation

An algorithm is proposed to estimate the parameters of transmission lines and transformers using synchronized phasor measurements at both ends of the element. It uses a simultaneous state and parameter estimation algorithm applied to an artificial system to find the parameters of the line or transformer. A number of successive data sets can be used to improve the accuracy of the estimation. The method can be combined with a resampling scheme to obtain very accurate values of constant parameters. It is also shown that this algorithm can track the values of time-varying parameters, including sudden changes resulting from line compensation or tap changing. The performance of the algorithm was tested by estimating all the parameters of the IEEE 30 bus test system, including one parameter that changes with time.

A model for the control of malaria using genetically modified vectors.

Recent works have considered the problem of using transgenic mosquitoes to control a malaria epidemic. These insects have been genetically engineered to reduce their capacity to infect humans with malaria parasites. We analyze a model of the mosquito population dynamics when genetically modified individuals are introduced into a wild type population so that the effect of their introduction can be assessed. The model describes the dynamics of gene selection under sexual reproduction in a closed vector population. Our results show that the fitness of the resulting heterozygous population is the key parameter for the success of the invasion, independently of the fitness of homozygous vectors. The vector population dynamics model is then combined with an epidemiological model to study the feasibility of controlling a malaria epidemic. Basic reproductive numbers are calculated for both models, and conditions are obtained for preventing reappearance of the epidemic. Simulations on this model show that it may be possible to reduce or even eradicate the epidemic only if the heterozygous population is better adapted than the wild type. They also show that this can be achieved without completely eliminating the wild type mosquitoes.

Burden of Disease and Economic Impact of Dengue and Severe Dengue in Colombia, 2011

OBJECTIVE To assess the burden of dengue disease in Colombia and its associated costs. METHODS We estimated the burden of dengue and severe dengue in Colombia for the period 2011 to 2014 on the basis of a dynamic model calibrated against Colombian surveillance data. The model estimated the annual number of dengue and severe dengue cases for those receiving medical care and those who do not. We calculated the average cost of care per patient on the basis of a bottom-up costing of cases, and additional costs were estimated for activities of vector control and other community interventions. Economic information from a sample of local and departmental vector control programs was reviewed. RESULTS The dynamic model estimated that for 2011 and 2012 there would be 56,998 dengue cases requiring medical attention (22,799 ambulatory and 34,199 hospitalized), 1851 cases of severe dengue, and 205 deaths. The economic analysis, with 2011 data, showed that Colombia would spend between US

Fuzzy Controller for MIMO Systems using Defuzzification based on Boolean Relations (DBR)

52.2 and US

Simultaneous estimation of exciter, governor and synchronous generator parameters using phasor measurements

61.0 million for dengue control activities and case management in an average year. Medical management costs would amount to US

Fuzzy model identification of dengue epidemic in Colombia based on multiresolution analysis

16.9 million (CI 95% 15.2-18.5 million), while vector control activities and other community interventions would cost between US

Transmission line’s parameter estimation using state estimation algorithms

37.08 and US

Mathematical model for the spread of drug resistance in Plasmodium falciparum parasite considering transmission conditions

42.41 million. CONCLUSIONS Dengue infection has an important impact on the health care system budget in Colombia. Most of the economic impact corresponds to community activities directed to prevent vector infestation (68.7%-71.0%), which are expensive and whose effectiveness is controversial.

Work in progress - Role of learning strategies in Electrical Circuits and Analog Electronics courses

This paper presents a methodology to control multiple input-multiple output systems using fuzzy logic and Boolean relations. The method proposes to design a fuzzy controller whose inference and defuzzification stages are simplified thanks to the synthesis of multivaluated functions. Using this approach, a nonlinear MIMO system is controlled in simulation. The synthesized controller is compared with a linearized state feedback and Mamdani controllers intended to the same application. Both control and computational complexity indices are considered in the comparison

Robust control of HIV-treatments using a polytopic model

The accuracy of the models used to predict the dynamic behavior of an electric power system is vital to ensure the stability and reliability of electricity supply. Parameter estimation of these models is essential for power system planners and operators to maintain a consistent and secure operating environment. In this work, the whole set of parameters of the synchronous generator coupled to the exciter and governor are estimated using an Unscented Kalman Filter, with input data from phasor measurements obtained by Phasor Measurement Units (PMU). Unlike other estimation methods previously used, excitation voltage and mechanical torque are estimated as states and only the measurements of the electrical power output, current phasor and voltage phasor at the generator terminals are required. A fast estimation algorithm is obtained that allows the estimation of all machine as well as velocity and voltage regulator parameters. Estimation is possible under different levels of measurement noise and initial operating conditions.