Diego Patino - Academia.edu (original) (raw)

Papers by Diego Patino

Energies

Selective Harmonics Elimination is a high-efficiency modulation method for multilevel inverters t... more Selective Harmonics Elimination is a high-efficiency modulation method for multilevel inverters that allows handling very high voltage applications. It eliminates the most significant harmonics and fixes the desired fundamental component. The main issue of these techniques is the complex process to obtain the appropriate switching-angles, being necessary to calculate them offline, meaning that if some disturbances occur, the system will not be compensated. This article proposes a real-time selective harmonic elimination for a single-phase cascaded multilevel inverter. The control strategy maintains constant the fundamental component of the output voltage while removing its third, fifth, and seventh order harmonics. The switching-angles are dynamically adapted to compensate for variations in the input voltage and the load. This is done by obtaining a virtual dynamic system using Groebner basis, an adaptation of the Newton-Raphson method, and implementing a digital PI controller into ...

Energies

Electricity access is strongly linked to human growth. Despite this, a portion of the world’s pop... more Electricity access is strongly linked to human growth. Despite this, a portion of the world’s population remains without access to energy. In Colombia, rural communities have energy challenges due to the National Interconnected System’s (NIS) lack of quality and stability. It is common to find that energy services in such locations are twice as costly as in cities and are only accessible for a few hours every day due to grid overload. Implementing market mechanisms that enable handling imbalances through the flexible load management of main loads within the grid is vital for improving the rural power grid’s quality. In this research, the energy from the rural grid is primarily employed to power a heating, ventilation, and air-conditioning (HVAC) system that chills flowers for future commerce. This load has significant consumption within the rural grid, so handling HVAC consumption in a suitable form can support the grid to avoid imbalances and improve the end-user access to energy. ...

2017 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA), 2017

this paper presents a novel control strategy for isolated multilevel inverters. This converter ha... more this paper presents a novel control strategy for isolated multilevel inverters. This converter has been chosen due to the autonomy of each full bridge. Other advantage is the feasibility of handling the power by cell when there are changes in the batteries state of charge (SOC). In order to take advantage of these benefits, a control strategy has been developed. The main goal of the proposed solution is to change the power produced by each inverter in function of SOC, guaranteeing a proper regulation of the overall power, without affecting the parameters of quality of the output voltage like harmonic distortion and amplitude. The designed solution was tested by power sources variations, finding the control strategy appropriate to accomplish the objective, to modify the power produced by each full bridge in function of SOC without changing overall power of the system and keeping the output voltage constant.

Energies, 2021

There is a need to look for alternative sources of renewable energy, especially in zones where pe... more There is a need to look for alternative sources of renewable energy, especially in zones where people continue to live under energy poverty conditions. Consequently, to enhance the performance of energy systems, algorithms to support planning decisions are required. This article proposes a simulation-optimization framework to solve the stochastic version of the integrated energy dispatch and unit commitment problem for a solar radiation system operating in non-interconnected zones. Our study was motivated by challenges faced by a rural school located in Cundinamarca, Colombia. Particularly, a simulation with optimization-based iterations approach is used, modeling solar radiation as a random variable. The optimization phase uses a heuristic procedure that enables good solutions to be found in short computational times. To test our method, computational experiments were conducted using a set of randomly generated cases. The results suggest that our approach is useful and able to hand...

Electronics, 2021

This article proposes an energy-efficiency strategy based on the optimization of driving patterns... more This article proposes an energy-efficiency strategy based on the optimization of driving patterns for an electric vehicle (EV). The EV studied in this paper is a commercial vehicle only driven by a traction motor. The motor drives the front wheels indirectly through the differential drive. The electrical inverter model and the power-train efficiency are established by lookup tables determined by power tests in a dynamometric bank. The optimization problem is focused on maximizing energy-efficiency between the wheel power and battery pack, not only to maintain but also to improve its value by modifying the state of charge (SOC). The solution is found by means of a Particle Swarm Optimization (PSO) algorithm. The optimizer simulation results validate the increasing efficiency with the speed setpoint variations, and also show that the battery SOC is improved. The best results are obtained when the speed variation is between 5% and 6%.

Energies, 2020

The integration of renewable generation adds complexity to the operation of the power system due ... more The integration of renewable generation adds complexity to the operation of the power system due to its unpredictable characteristics. Therefore, the development of methods to accurately model the uncertainty is necessary. In this paper, the spatio-temporal kriging and analog approaches are used to forecast wind power generation and used as the input to solve an economic dispatch problem, considering the uncertainties of wind generation. Spatio-temporal kriging captures the spatial and temporal information available in the database to improve wind forecasts. We evaluate the performance of using the spatio-temporal kriging, and comparisons are carried out versus other approaches in the framework of the economic power dispatch problem, for which simulations are developed on the modified IEEE 3-bus and IEEE 24-bus test systems. The results demonstrate that the use of kriging based spatio-temporal models in the context of economic power dispatch can provide an opportunity for lower oper...

Electronics, 2020

The estimation of the state of charge is a critical function in the operation of electric vehicle... more The estimation of the state of charge is a critical function in the operation of electric vehicles. The battery management system must provide accurate information about the battery state, even in the presence of failures in the vehicle sensors. This article presents a new methodology for the state of charge estimation (SOC) in electric vehicles without the use of a battery current sensor, relying on a virtual sensor, based on other available vehicle measurements, such as speed, battery voltage and acceleration pedal position. The estimator was derived from experimental data, employing support vector regression (SVR), principal component analysis (PCA) and a dual polarization (DP) battery model (BM). It is shown that the obtained model is able to predict the state of charge of the battery with acceptable precision in the case of a failure of the current sensor.

DYNA, 2019

Electric faults in photovoltaic (PV) systems cause negative economic and safety impacts, reducing... more Electric faults in photovoltaic (PV) systems cause negative economic and safety impacts, reducing their performance and causing unwanted electric connections that can be dangerous for the user. Line to line, ground and open circuit faults, are three of the main faults that happen in a photovoltaic array system. This work proposes a characterization of the equivalent circuits and the voltage-power (VP) curves at the output of multiple PV arrays under different topological configurations and fault conditions to evaluate the effects of these three main faults on the performance of a photovoltaic array system, taking into account the temperature and solar radiation influence. This work presents a validation of the characterization by measuring the output VP curves of a low-power photovoltaic array system under real outdoors conditions. This method can be useful in future works to develop low cost systems capable of detecting and classifying electric faults in photovoltaic array systems.

Journal of Advanced Transportation, 2020

The eco-driving profiles are algorithms able to use additional information in order to create rec... more The eco-driving profiles are algorithms able to use additional information in order to create recommendations or limitation over the driver capabilities. They increase the autonomy of the vehicle but currently their usage is not related to the autonomy required by the driver. For this reason, in this paper, the eco-driving challenge is translated into two-layer optimal controller designed for pure electric vehicles. This controller is oriented to ensure that the energy available is enough to complete a demanded trip, adding speed limits to control the energy consumption rate. The mechanical and electrical models required are exposed and analyzed. The cost function is optimized to correspond to the needs of each trip according to driver behavior, vehicle, and traject information. The optimal controller proposed in this paper is a nonlinear model predictive controller (NMPC) associated with a nonlinear unidimensional optimization. The combination of both algorithms allows increasing a...

Revista Iberoamericana de Automática e Informática industrial, 2019

En este artículo se propone un modelo para la predicción de demanda de energía eléctrica a corto ... more En este artículo se propone un modelo para la predicción de demanda de energía eléctrica a corto plazo empleando técnicas de estimación Set Membership. El modelo está compuesto por una componente periódica y una componente no-lineal auto-regresiva generada por un modelo no-paramétrico adaptable que incorpora datos recientes al conjunto de identificación en cada iteración del algoritmo. El modelo es evaluado en un caso de estudio con mas de 13,000 muestras de demanda horaria a lo largo de tres años, registradas en un municipio rural de Colombia. El desempeño del estimador se compara con un modelo lineal auto-regresivo y un modelo Set Membership con conjunto de identificación fijo. Los resultados muestran que el estimador propuesto logra predecir la demanda de energía con un error RMS inferior al 2.5 % en datos de validación, empleando solo un 5 % de los datos disponibles para la construcción del modelo.

IEEE Latin America Transactions, 2018

This article presents a multi-variable control strategy for the regulation of Dissolved Oxygen Co... more This article presents a multi-variable control strategy for the regulation of Dissolved Oxygen Concentration in a stirred laboratory-scale bioreactor. The controller manipulates the airflow and agitation speed in the reactor. Departing from a mechanistic model that relates the manipulated variables and the oxygen transfer coefficient, linearized local models of the process are obtained. It is observed that there is high variability in the process behavior with the operating point. Then, a Gain-Scheduled controller is proposed. The strategy varies the agitation speed employing a PI control law and varies the air flow according to a switching law that detects saturations in the manipulated variables. The proposed strategy is evaluated in simulation and implemented in a real bioreactor. Results show that the strategy is able to regulate the oxygen concentration in a wide range of operating conditions.

Revista Politécnica, 2018

Smart grids are playing a key role in modern electric power grids, improving load control, assuri... more Smart grids are playing a key role in modern electric power grids, improving load control, assuring safer operations and collecting valuable information of the electrical conditions of the grid. In a smart grid, a RTU (Remote Terminal Unit) is a device that is able to measure the electric variables of the grid and sends all the information to a MTU (Master Terminal Unit), which is responsible of controlling the operations of the grid. RMU (Ring Main Unit) devices are used in electric power grids to protect loads and to disconnect them in case of failure to prevent damage. This article presents the design of a special RMU capable of measuring voltage, current and frequency, detecting electric faults, and making automatic self-healing in order to manage the flow of energy in the smart grid to guarantee energy supply to the critical loads (hospitals). The RMU devices were installed on a scaled smart grid in order to show its operation capabilities.

Journal of Sound and Vibration, 2017

Ti t l e F u n d a m e n t al s of a c tiv e s hi el di n g b a s e d o n im plicit c o n t r ol

Applied Energy, 2017

h i g h l i g h t s A dynamic model of a Water Booster Pressure Systems is proposed and validated... more h i g h l i g h t s A dynamic model of a Water Booster Pressure Systems is proposed and validated. It is achieved a 27% flexibility in the power consumption without stopping water flow. A strategy to offer spinning reserve services with a systems aggregation is presented. A controller for the aggregator is designed and evaluated in simulation.

Ingenieria Y Universidad, May 23, 2011

aceptación: 15 de diciembre de 2011. Este artículo se deriva de un proyecto de investigación deno... more aceptación: 15 de diciembre de 2011. Este artículo se deriva de un proyecto de investigación denominado Convertidor multinivel de alto voltaje, desarrollado por el grupo de investigación Control,

We solve non-convex, variational problems in the form min u I(u) = 1 0 f (u (x))dx s.t. u(0) = 0,... more We solve non-convex, variational problems in the form min u I(u) = 1 0 f (u (x))dx s.t. u(0) = 0, u(1) = a, (1) where u ∈ (W 1,∞ (0, 1)) k and f : R k → R is a non-convex, coercive polynomial. To solve (1) we analise the convex envelope fc at the point a, this means to find vectors a 1 ,. .. , a N ∈ R k and positive values λ1,. .. , λN satisfying the non-linear equation (1, a, fc(a)) = N i=1 λi(1, a i , f (a i)). (2) With this information we calculate minimizers of (1) by following a proposal of B. Dacorogna in [15]. We represent the solution of (2) as the minimizer of one particular convex, optimization problem defined in probability measures which can be transformed into a semidefinite program by using necessary conditions for the solution of the multidimensional moments problem. To find explicit solutions of (1), we use a constructive, a posteriori approach which exploits the characterization of one dimensional moments on the marginal moments of a bivariate distribution. By following J.B. Lasserre's proposal on global optimization of polynomials [25], we determine conditions on f and a to obtain exact semidefinite relaxations of (1).

2015 IEEE 2nd Colombian Conference on Automatic Control (CCAC), 2015

2010 IEEE ANDESCON, 2010

In this article, we present a method for computing an optimal state feedback control law for swit... more In this article, we present a method for computing an optimal state feedback control law for switched affine systems which do not have common equilibrium points. The hybrid solution is obtained from a general convex formulation for which the existence of the optimal solution is guaranteed. We show that the synthesis of the optimal trajectories yields a partition of the state space with respect to the mode. The design uses singular arcs which are obtained through an algebraic condition. In order to test the performance of the control law, an academical buck converter is taken as an example with a quadratic and a minimum time criteria.

Proceedings of the 11th International Conference on Informatics in Control, Automation and Robotics, 2014

Bat wings contain dozens of joints that enable the animal to perform aggressive maneuvers by mean... more Bat wings contain dozens of joints that enable the animal to perform aggressive maneuvers by means of changing the wing shape during flight. There is evidence that the inertial forces produced by their wings during flapping have a key role in the attitude movements of the animal, i.e. aerial rotations. In fact, bats efficiently generate net body forces to manoeuvre by taking advantage of their large wing-to-body mass ratio. In this paper, the following question is formulated: Could a Micro Aerial Vehicle (MAV) inspired by the biomechanics of bats take advantage of the morphing-wings aimed at increasing net body forces? Using BaTboT, a novel bat-like MAV with highly articulated wings actuated by shape memory alloy actuators, our goal is to quantify the effects of different wing modulation patterns on the generation of net body forces. Experiments are carried out to confirm the important physical role that changing the wing shape enables: the contraction time of the wings (upstroke) should be faster than the extension time (downstroke), taking about 37.5% of the wingbeat period. This modulation pattern has enabled a lift force increment of 22% (from L = 0.92N to L = 1.12N), abrupt drag reduction (from D = 0.22N to D = 0.11N) and also an increase of net body forces (F net) about 28% compared to those wing modulation patterns defined with equal periods for contraction/extension. These findings can be useful for accurate dynamics modelling and efficient design of flight controllers applied to morphing-wing micro aerial vehicles.

Numerical Functional Analysis and Optimization, 2010

A numerical method for a (possibly non-convex) scalar variational problem for the functional Φ(u)... more A numerical method for a (possibly non-convex) scalar variational problem for the functional Φ(u) := Ω ϕ 1 (x, ∇u(x)) + ϕ 0 (x, u(x)) dx to be minimized for u ∈ W 1,p (Ω) and u| ∂Ω = u D , is proposed; Ω ⊂ R n is a bounded Lipschitz domain, n = 1 or 2. This method allows for computation of the Young-measure solution of the generalized relaxed version of the original problem and applies to those cases in which ϕ 1 (x, •) is polynomial. The Young measures involved in the relaxed problem can be represented by their algebraic moments and a finite-element mesh is used to discretize Ω and thus to approximate both u and the Young measure (in the momentum representation). Eventually, thus obtained convex semidefinite program can be solved by efficient specialized mathematical-programming solvers. This method is justified by convergence analysis and eventually tested on a 2-dimensional benchmark numerical example. It serves as an example how convex compatification can efficiently be used numerically if enough "small", i.e. enough coarse.

Energies

2017 IEEE Workshop on Power Electronics and Power Quality Applications (PEPQA), 2017

Energies, 2021

Electronics, 2021

Energies, 2020

Electronics, 2020

DYNA, 2019

Journal of Advanced Transportation, 2020

Revista Iberoamericana de Automática e Informática industrial, 2019

IEEE Latin America Transactions, 2018

Revista Politécnica, 2018

Journal of Sound and Vibration, 2017

Ti t l e F u n d a m e n t al s of a c tiv e s hi el di n g b a s e d o n im plicit c o n t r ol

Applied Energy, 2017

Ingenieria Y Universidad, May 23, 2011

2015 IEEE 2nd Colombian Conference on Automatic Control (CCAC), 2015

2010 IEEE ANDESCON, 2010

Proceedings of the 11th International Conference on Informatics in Control, Automation and Robotics, 2014

Numerical Functional Analysis and Optimization, 2010