Browsing by Author "Montoya O.D."

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A generalized passivity-based control approach for power compensation in distribution systems using electrical energy storage systems
(Elsevier Ltd, 2018) Montoya O.D.; Garcés, Alejandro; Espinosa-Pérez, G.
This paper presents a generalized interconnection and damping assignment passivity-based control (IDA-PBC) for electric energy storage systems (EESS) such as: superconducting magnetic energy storage (SMES) and supercapacitor energy storage (SCES). A general framework is proposed to represent the dynamical behavior of EESS interconnected to the electrical distribution system through forced commutated power electronic converters. A voltage source converter (VSC) and a pulse-width modulated current source converter (PWM-CSC) are used to integrate SCES and SMES systems to the electrical power systems respectively. The proposed control strategy allows active and reactive power interchange between the EESS and electric distribution grids independently, guaranteeing globally asymptotically convergence in the sense of Lyapunov via Hamiltonian formulation. Simulation results show the effectiveness and robustness of the generalized IDA-PBC to operate EESS as active and reactive power compensator in order to improve operative conditions in power distribution grids under balanced and unbalanced conditions. © 2018 Elsevier Ltd
A New Approach for the Monte-Carlo Method to Locate and Size DGs in Distribution Systems
(Institute of Electrical and Electronics Engineers Inc., 2018) Grisales-Noreña L.F.; Montoya O.D.; González-Montoya D.; Ramos-Paja C.A.
This paper proposes a new approach for a Parallel implementation of Monte-Carlo method aimed for optimal location and sizing of distributed generators in distribution networks. In this approach, a reduction of the solution space is performed, using heuristic strategies, to improve processing times, power losses and voltage profiles considering the location of distributed generators in electric distribution networks. The mathematical formulation of the problem considers a single-objective function, which is composed by weighting factors associated with active power losses and square voltage error minimization; moreover, classical power flow constraints and distributed generation capabilities are considered as restrictions. A master-slave optimization strategy is used to solve the problem: the master stage corresponds to the proposed parallel Monte-Carlo with space solution reduction, which performs the optimal location of the distributed generators; the slave strategy is in charge of solving the resulting optimal power problem. Classical 33-node and 69node test systems are used to validate the proposed approach via MATLAB/MATPOWER software. For comparison purposes, the loss sensitivity factor (LSF), genetic algorithm (GA) and classical parallel Monte-Carlo (PMC) solutions are also tested. The simulations confirm that the proposed reduction to the space solution for the PMC provides improved results in comparison with the existing approaches. © 2018 IEEE.
A Sequential Quadratic Programming Model for the Economic-Environmental Dispatch in MT-HVDC
(Institute of Electrical and Electronics Engineers Inc., 2019) Montoya O.D.; Gil-González, Walter; Garcés, Alejandro
This paper addresses the economic-environmental dispatch problem for thermal plants on a Multi-terminal HVDC power grid. A multi-objective optimization approach is used for modeling the compromise between fuel costs and the greenhouse gas emissions by the thermal plants. The grid topology is also considered by proposing a convex reformulation of the power balance equations through Taylor's series expansion method. To eliminate the error introduced by this linear approximation a sequential quadratic programming approach is applied by solving the multi-objective problem by a single-objective equivalent via weighting factor approach. A standard 6-node HVDC system is used to validate the proposed convex formulation. All simulations are performed in MATLAB with the quadprog optimization package. © 2019 IEEE.
Alternative power flow method for direct current resistive grids with constant power loads: A truncated Taylor-based method
(Institute of Physics Publishing, 2019) Montoya O.D.; Gil-González W.; Marulanda J.J.; Suarez E.G.; Diaz B.Z.; Nino E.D.V.
The power flow in electrical system permits analyzing and studying the steady-state behavior of any grid. Additionally, the power flow helps with the proper planning and management of the system. Therefore, it is increasingly necessary to propose power flows with fast convergence and high efficiency in their results. For this reason, this paper presents an alternative power flow approach for direct current networks with constant power loads based on a truncated Taylor-based approximation. This approach is based on a first-order linear approximation reformulated as a recursive, iterative method. It works with a slope variable concept based on derivatives, which allow few iterations and low processing times. Numerical simulations permit identifying the best power flow approaches reported in the specialized literature for radial and mesh dc grids, including the proposed approach. All the simulations were conducted in MATLAB 2015a. © Published under licence by IOP Publishing Ltd.
An Exact Feedback Linearization Control of a SMES System to Support Power in Electrical Grids
(Institute of Electrical and Electronics Engineers Inc., 2018) Montoya O.D.; Garrido Arévalo, Víctor Manuel; Gil-González W.; Holguín E.; Garces A.
This paper presents an exact feedback linearization control strategy to operate superconducting magnetic energy storage (SMES) systems connected to an electric distribution network through a pulse-width-modulated current source converter (PWM-CSC). To model this system an average model is employed by using dq reference frame. The dynamical model of the SMES system considering the PWM-CSC is transformed algebraically into an equivalent linear model by simple substitutions, avoiding to use an equivalent linearization technique or Taylor's series. The linear model preserves all features of the nonlinear model, which allows obtaining control laws to be applicable in its non- linear system. The proposed control scheme permits the active and reactive control of the SMES system in a wide range of operating independently. The effectiveness and the robustness of the proposed control methodology are tested in a low-voltage distribution network considering unbalance and high harmonic distortion in the voltage provided by the utility. All simulation cases are carried out in MATLAB/ODE environment under time domain reference frame, and they are compared with a conventional PI controller. © 2018 IEEE.
An exact MINLP model for optimal location and sizing of DGs in distribution networks: A general algebraic modeling system approach
(Ain Shams University, 2019) Montoya O.D.; Gil-González W.; Grisales-Noreña L.F.
This paper addresses the classical problem of optimal location and sizing of distributed generators (DGs) in radial distribution networks by presenting a mixed-integer nonlinear programming (MINLP) model. To solve such model, we employ the General Algebraic Modeling System (GAMS) in conjunction with the BONMIN solver, presenting its characteristics in a tutorial style. To operate all the DGs, we assume they are dispatched with a unity power factor. Test systems with 33 and 69 buses are employed to validate the proposed solution methodology by comparing its results with multiple approaches previously reported in the specialized literature. A 27-node test system is also used for locating photovoltaic (PV) sources considering the power capacity of the Caribbean region in Colombia during a typical sunny day. Numerical results confirm the efficiency and accuracy of the MINLP model and its solution is validated through the GAMS package. © 2019 Ain Shams University
Analysis of Power Losses in Electric Distribution System Using a MATLAB-Based Graphical User Interface (GUI)
(Springer, 2019) Rojas L.A.; Montoya O.D.; Campillo Jiménez, Javier Eduardo; Figueroa-Garcia J.C.; Duarte-Gonzalez M.; Jaramillo-Isaza S.; Orjuela-Canon A.D.; Diaz-Gutierrez Y.
This paper describes a graphical user interface (GUI) developed in MATLAB that provides a user-friendly environment for analyzing the power loss behavior in distribution networks with radial configurations. This GUI allows power systems analysts an easier understanding of the effect of the power dissipation in conductors. The implementation of this GUI implements three radial test feeders using 10, 33 and 69 nodes. As power flow methodology, the successive approximation power flow method was employed. The proposed GUI interface allows identifying the power loss performance in the distribution networks by including a distributed generator (DG) into the grid, operating with unity power factor. This DG is connected to each node to determine which connection provides with the optimal power loss minimization. Numerical results supported by the graphical analysis validate the applicability and importance of user-friendly GUI interfaces for analyzing power systems. © 2019, Springer Nature Switzerland AG.
Control for EESS in Three-Phase Microgrids under Time-Domain Reference Frame via PBC Theory
(Institute of Electrical and Electronics Engineers Inc., 2019) Montoya O.D.; Gil-González W.; Garces A.
This brief presents a general form of designing passivity-based controllers for electrical energy storage systems (EESS) in three-phase microgrids (TP-MGs) under time-domain reference frame. The control strategy proposed in this brief use the Clark's transformation known as αβ reference frame, avoiding to use phase-locked loop systems, which allows improving the dynamical performance in the energy storage devices. Passivity-based control guarantees stable operating conditions in the sense of Lyapunov for each EESS for different grid operation scenarios in the TP-MG. The design of the controllers is made by using passivity-based control (PBC) theory in conjunction to the dynamics of the error approach. A comparison to classical proportional-integral control method is used to show the applicability of the PBC approach presented in this brief. Simulation results are conducted via MATLAB/Simulink software. © 2004-2012 IEEE.
Control of a SMES for mitigating subsynchronous oscillations in power systems: A PBC-PI approach
(Elsevier Ltd, 2018) Gil-González W.; Montoya O.D.; Garces A.
This paper proposes a methodology to control the active and reactive power of a superconducting magnetic energy storage (SMES) system to alleviate subsynchronous oscillations (SSO) in power systems with series compensated transmission lines. Primary frequency and voltage control are employed to calculate the active and reactive power reference values for the SMES system, and these gains are calculated with a particle swarm optimization (PSO) algorithm. The proposed methodology is assessed with a classical PI controller, feedback linearization (FL) controller and a passivity-based PI control (PI-PBC). Operating limits for VSC are also considered, which gives priority to active power over reactive power. The IEEE Second Benchmark model is employed to demonstrate the assessment of the proposed methodology where PI-PBC presents better performance than the classical PI and FL controllers in all the operating conditions considered. © 2018 Elsevier Ltd
Controller design for VSCs in distributed generation applications: An IDA-PBC approach
(Institute of Electrical and Electronics Engineers Inc., 2019) Montoya O.D.; Garrido Arévalo, Víctor Manuel; Gil-González, Walter; Garces A.; Grisales-Noreña L.F.
This paper presents an asymptotically stable global controller design for distributed energy integration in electrical distribution networks using a three-phase voltage source converter (VSC). An invariant Park's transformation is used to obtain the mathematical representation of the VSC in dq0 reference frame. To design of the proposed controller, interconection and damping assignment passivity-based control (IDA-PBC) theory is applied via a Hamiltonian representation for the open-loop dynamic as well as the desired closed-loop dynamic of the system. The control law obtained allows guaranteeing asymptotic stability properties in the sense of Lyapunov for closed-loop operation. To verify the robustness and effectiveness of the proposed controller a classic connection of a distributed generator with a VSC converter using an ideal voltage source in its DC side is employed. Simulation results show the capability of the proposed controller to support active and reactive power independently under unbalance voltage conditions and harmonic distortion as well as the possibility of using the VSC as a dynamic power factor corrector. Additionally, all simulation scenarios are compared to classic PI controllers to show the good dynamic performance of the proposed controller using IDA-PBC theory. MATLAB/SIMULINK software is employed as simulation environment. © 2018 IEEE.
Current PI Control for PV Systems in DC Microgrids: A PBC Design
(Institute of Electrical and Electronics Engineers Inc., 2019) Gil-González, Walter; Garces A.; Montoya O.D.
This paper proposes a passive PI control for applications of photovoltaic (PV) systems integrated with boost DC-DC converters. The proposed controller guarantees asymptotically stability in closed-loop for the boost DC-DC converter using Lyapunov theory. In addition, the proposed controller is robust to parametric uncertainties and unmodeled dynamics since it does not depend on the system parameters. The current control mode is selected for the PV system since it is modeled as a current source, where its current is computed as a function of solar irradiance and the cells temperature. The current reference is calculated to a perturbing and observe MPPT algorithm with a current-mode controlled to extract the maximum power available in this solar source. The PI-PBC applied to the boost DC-DC converter is compared with a classical PI approach for validating its effectiveness and the robustness. Simulation results are performed in MATLAB/Simulink with a switching frequency of 5 kHz. © 2019 IEEE.
DERs integration in microgrids using VSCs via proportional feedback linearization control: Supercapacitors and distributed generators
(Elsevier Ltd, 2018) Montoya O.D.; Garcés, Alejandro; Serra F.M.
This paper presents an exact feedback linearization control strategy for voltage source converters (VSCs) applied to the integration of distributed energy resources (DERs) in smart distribution systems and microgrids. System dynamics is represented by an average nonlinear model which is transformed algebraically into an equivalent linear model by simple substitutions, avoiding to use Taylor's series or another equivalent linearization technique. The equivalent linear model preserves all characteristics of the nonlinear model, which implies that the control laws obtained are completely applicable on its nonlinear representation. Stability analysis is made using the passivity-based technique. The exact feedback linearization control in combination with passivity-based control (PBC) theory guarantees to obtain a global asymptotically stable controller in the sense of Lyapunov for its closed-loop representation. The effectiveness and robustness of the proposed methodology is tested in a low-voltage microgrid with a photovoltaic system, a supercapacitor energy storage (SCES) device and unbalance loads. All simulation scenarios are conducted in MATLAB/SIMULINK environment via SimPowerSystem library. © 2018 Elsevier Ltd
Determination of the Voltage Stability Index in DC Networks with CPLs: A GAMS Implementation
(Springer, 2019) Amin W.T.; Montoya O.D.; Grisales-Noreña L.F.; Figueroa-Garcia J.C.; Duarte-Gonzalez M.; Jaramillo-Isaza S.; Orjuela-Canon A.D.; Diaz-Gutierrez Y.
This paper addresses the voltage collapse analysis in direct-current (DC) power grids via nonlinear optimization approach. The formulation of this problem corresponds to an optimization problem, where the objective function is the maximization of the loadability consumption at all the constant power loads, subject to the conventional power flow balance equations. To solve this nonlinear non-convex optimization problem a large-scale nonlinear optimization package known as General Algebraic Modeling System (GAMS) is employed. Different nonlinear solvers available in GAMS are used to confirm that the optimal solution has been reached. A small 4-node test system is used to illustrate the GAMS implementation. Finally, two test systems with 21 and 33 nodes respectively, are used for simulation purposes in order to confirm both the effectiveness and robustness of the nonlinear model, and the proposed GAMS solution methodology. © 2019, Springer Nature Switzerland AG.
Direct power control for VSC-HVDC systems: An application of the global tracking passivity-based PI approach
(Elsevier Ltd, 2019) Gil-González W.; Montoya O.D.; Garces A.
This paper proposes a direct power control (DPC) for a high-voltage direct-current system using voltage source converters (VSC-HVDC) by applying passivity-based control theory. This system allows doing an efficient and reliable integration of electrical network from renewable energy sources. The DPC model permits instantaneous control of the active and reactive power without employing the conventional inner-loop current regulator and the phase-locked loop, thus diminishing investment costs and increasing the reliability of the system. The proportional-integral passivity-based control (PI-PBC) is chosen to control the direct power model of the VSC-HVDC system since this system exhibits a port-Hamiltonian formulation in open-loop and as PI-PBC can exploit this formulation to design a PI controller, which guarantees asymptotically stable in closed-loop based on Lyapunov's theory. Passivity-based control is an active research subject in the control community which has gained a reputation of being a very theoretical subject. Nevertheless, it can have advantages from a practical point of view including an implementation similar to the conventional controls for power systems applications. The paper is oriented to the power & energy systems community, taking into account this practical approach. The proposed controller is assessed by simulations in a two-terminal VSC-HVDC system and compared with a PI direct power controller. Four simulation conditions using MATLAB/SIMULINK were conducted to verify the effectiveness of PI-PBC against a PI controller and a perturbation observer-based adaptive passive control under various operating conditions. © 2019 Elsevier Ltd
Direct power control of electrical energy storage systems: A passivity-based PI approach
(Elsevier Ltd, 2019) Gil-González, Walter; Montoya O.D.; Garces A.
This paper proposes a direct power control for electrical energy storage systems (EESS) in ac microgrids. This strategy allows managing instantaneous active and reactive power without using a conventional inner-loop current regulator and without a phase-locked loop, increasing the reliability of the system while reducing investment costs. PI passivity-based control (PI-PBC) is selected to control the direct power model of EESS. This is because their models exhibit a port-Hamiltonian formulation in open-loop, and PI-PBC exploits this formulation to design a PI controller, which guarantees global asymptotically stability in closed-loop in the sense of Lyapunov. Simulations tested the proposed model in a microgrid and compared with conventional vector oriented controls in a dq reference frame and a direct power model controlled via feedback linearization (FL). PI-PBC has a better performance than other two controllers in all considered scenarios. Simulation results have conducted through MATLAB/SIMULINK software by using the SimPowerSystem toolbox. © 2019 Elsevier B.V.
Distributed energy resources integration in single-phase microgrids: An application of IDA-PBC and PI-PBC approaches
(Elsevier Ltd, 2019) Montoya O.D.; Gil-González W.; Garces A.
This paper presents a unified Hamiltonian formulation for controlling distributed energy resources (DERs)in ac single-phase microgrids (SP-MGs)via proportional-integral passivity-based control (PI-PBC), and interconnection and damping assignment passivity-based control (IDA-PBC). The proposed Hamiltonian formulation allows us to consider both pulse-width modulated voltage source converters (PWM-VSC)and pulse-width modulated current source converters (PWM-CSC)under a unified model. Renewable generation and supercapacitor energy storage systems are integrated via PWM-VSC technologies, while superconducting coils are integrated through PWM-CSC technologies. IDA-PBC and PI-PBC theories enable us to design control strategies begin that consider Lyapunov's stability theory combined with the well-known advantages of proportional and integral control actions. Our simulation's results corroborate the applicability of the proposed control approaches under stability paradigm. MATLAB/Simulink is employed for computational implementations via begin the SimPowerSystems toolbox. © 2019 Elsevier Ltd
Economic Dispatch of BESS and renewable generators in DC microgrids using voltage-dependent load models
(MDPI AG, 2019) Montoya O.D.; Gil-González W.; Grisales-Noreña L.F.; Orozco-Henao C.; Serra F.
This paper addresses the optimal dispatch problem for battery energy storage systems (BESSs) in direct current (DC) mode for an operational period of 24 h. The problem is represented by a nonlinear programming (NLP) model that was formulated using an exponential voltage-dependent load model, which is the main contribution of this paper. An artificial neural network was employed for the short-term prediction of available renewable energy from wind and photovoltaic sources. The NLP model was solved by using the general algebraic modeling system (GAMS) to implement a 30-node test feeder composed of four renewable generators and three batteries. Simulation results demonstrate that the cost reduction for a daily operation is drastically affected by the operating conditions of the BESS, as well as the type of load model used. © 2019 MDPI AG. All rights reserved.
Economic dispatch of energy storage systems in dc microgrids employing a semidefinite programming model
(Elsevier Ltd, 2019) Gil-González W.; Montoya O.D.; Holguín E.; Garces A.; Grisales-Noreña L.F.
A mathematical optimization approach for the optimal operation focused on the economic dispatch for dc microgrid with high penetration of distributed generators and energy storage systems (ESS) via semidefinite programming (SDP) is proposed in this paper. The SDP allows transforming the nonlinear and non-convex characteristics of the economic dispatch problem into a convex approximation which is easy for implementation in specialized software, i.e., CVX. The proposed mathematical approach contemplates the efficient operation of a dc microgrid over a period of time with variable energy purchase prices, which makes it a practical methodology to apply in real-time operating conditions. A nonlinear autoregressive exogenous (NARX) model is employed for training an artificial neural network (ANN) for forecasting solar radiation and wind speed for renewable generation integration and dispatch considering periods of prediction of 0.5 h. Four scenarios are proposed to analyze the inclusion of ESS in a dc microgrid for economic dispatch studies. Additionally, the results are compared with GAMS commercial optimization package, which allows validating the accuracy and quality of the proposed optimizing methodology. © 2018 Elsevier Ltd
Group-Theory for the Analysis of Heuristic Algorithms in Power Distribution Systems
(Institute of Electrical and Electronics Engineers Inc., 2018) Garces A.; Gil-González, Walter; Castano J.; Montoya O.D.
This paper applies group theory to four classic problems in power distribution systems, namely: phase balancing, primary feeder reconfiguration, optimal tap setting of voltage regulator transformers and optimal placement of fixed capacitors. The main focus of the paper is in the codification and the use of groups as a tool for analysis. A simple random search algorithm is used as a test for the first problem. It is demonstrated that the groups formalism allows a simple analysis of heuristics and could be an interesting path for future investigations. © 2018 IEEE.
Heuristic approach for optimal location and sizing of distributed generators in AC distribution networks
(World Scientific and Engineering Academy and Society, 2019) Bocanegra S.Y.; Montoya O.D.
This paper addresses, from a heuristic point of view, the problem of the optimal location and sizing of distributed generators (DGs) in alternating-current distribution networks with radial topology. A master–slave optimization approach is followed to place and size the DGs. In the master stage a simple recursive seach method based on sequential searching is proposed. In the case of the slave algorithm, we present an emerging metaheuristic for solving the optimal power flow problem. This metaheuristic is called the vortex search algorithm. It works with a Gaussian distribution and a variable radius function for exploring and exploiting the solution space. Numerical simulations of 33-and 69-node test feeders show its efficiency, simplicity and robusteness in comparison to other methods in the literature. © 2019, World Scientific and Engineering Academy and Society. All rights reserved.