E. A. Cano-Plata

Hybrid simulation to test control strategies in active power filters using generalized power tensor theory

This paper presents a hybrid simulation to test control strategies in active power filters using the generalized power tensor theory. The tensor theory is based on the dyadic or tensor product between voltage and current vectors. This new definition allows the estimate of reference currents for the control of active power filters “APFs” in multiphase systems. The hybrid simulation consists in a combination of computer simulation and laboratory tests. This approach is a cost effective alternative to physically testing the whole system and allows study the dynamic behaviour of complex engineering systems. Besides, it describes implementing an active power filter (APF) hybrid prototype where the source system and load are implemented as a real-time simulation and the active power filter is implemented in physical hardware. It also confirmed the hybrid simulation results by implementing the simulation in MATLAB-Simulink regarding the same system implemented during the active power filter analysis and design stage.

Analysis of Voltage Sag Severity Case Study in an Industrial Circuit

This paper presents the results of a power quality study carried out in an industrial distribution system. The main objective of this study was to quantify the negative impact caused by voltage sags in industrial processes and its relationship to generated interruptions. A series of measurements of power quality variations were taken at the substation that feeds the circuit and at the point-of-common coupling of each industrial user. The new standard IEEE Std 1564-2014 “Guide for Voltage Sag Indices” was used to determine the indicators to assess the severity of voltage sags and also the calculation method. Sag severity was selected as it allows the calculation of the probability of voltage sags to generate interruptions in industrial processes or electrical equipment. Thus, an analysis of the quality of the supply voltage can be done. Severity was initially calculated at the substation that feeds the industrial circuit and later, at the point-of-common coupling of each user. Subsequently, the relationship between user interruptions and severity values was determined. Finally, recommendations of good engineering practices in industrial processes were done.

Visualizing two- and three-dimensional maps for power quality loss assessment

Constructing maps of loss or deterioration of power quality, due to stationary and non-stationary disturbances, is of great importance for the control, protection and analysis of power systems. Therefore, a technique for two- and three-dimensional maps visualization of the deterioration of power quality in electrical networks based in the power tensor theory is proposed. The objective of the technique is to provide images of the electrical network with easily identifiable characteristics through the construction of graphic schemes (maps) of power quality loss. Finally, the effectiveness of the tool is illustrated via different scenarios which are created using the IEEE 13-bus test feeder as an example.

Validation and reception of electric arc furnace transformers

The electric arc furnace transformer is one of the most important devices in the steelmaking industry. Installing used transformers is very common nowadays taking into account the huge investment that represents the acquisition of a new one. The transformer is subjected to electrical stress, thus it is necessary to assess the wear and tear levels in the reception process before accepting a trade agreement and before setting the device into operation. Analysis parameters are the input variables of a new fuzzy model to calculate the remaining life of the transformer.

Teoría generalizada de la potencia instantánea aplicada a la compensación de cargas polifásicas

The use of the instantaneous reactive power theory is greater than before due to the increased interest to use active power filters to compensate the non-sinusoidal currents produced by nonlinear loads. However, this theory can only be applied to three-phase systems of three or four conductors. This paper presents a new definition of instantaneous power that can be applied to all multiphase systems. Thus, the concept of tensor product is introduced to define the instantaneous power tensor and also the current decomposition in active and reactive components regardless of the number of phases of the power system. Finally, an exhaustive analysis of practical cases has been carried out at a simulation level which verified the proposed approach.

Modeling of a centralized microgrid protection scheme

This paper presents the simulation and modeling process of an over-current protection scheme with pre-established configurations and centralized control of such configurations. Consequently, it was necessary to classify, characterize and parameterize the different protection schemas proposed in the related literature. In addition, a digital relay protection adaptation and a centralized decision scheme are proposed. Finally, the microgrid model characteristics and its implementation in MATLAB/SIMULINK, with their respective results, are presented.

Waveform characteristics assessment by the operation of protective devices

Power system protection coordination plays the main role in the continuity of service in electrical systems. Incorrect settings may allow that repetitive failures occur before triggering an interruption. Consequently, it is necessary to identify the devices that clear a fault to assess its operation. The identification process can be achieved by a signature that each device induces in the voltage and current waveforms. As a proposal, this article presents a new method in the analysis of the transients related to the operation of the protections in the distribution systems for identification of protective devices. This method has the ability to detect transient changes and characterize the quality disturbances of three-phase systems.

Application of complexity theory to hydro-turbine maintenance

Hydro-turbine maintenance would be made easier by measuring the multi-scale entropy of its sound and the magnetic waves produced. Currently used methods include parametric solid modeling, FEA analysis, CFD simulation, CAD design & drafting, PLC & SCADA programming, protections, engineering & testing, and power quality testing, among others. The purpose of this paper is to explore specific connections between hydropower and complexity science. Recent trends in the processing of multiscale entropy of the physical signs are parallel to the advances in mathematical chaos and fractal theory. The presentation of the basic equations of the theory of entropy and complexity are shown in this study, in order to process data generated by turbines and create new procedures to assess them. Electrical circuits dissipate energy and manipulate intelligence. This paper proposes to analyze them from the of entropy and complexity point of view. Electromagnetic signals generated by circuits, such as turbines, can be demodulated to gain useful information.

Optimal process in electric arc furnaces

Recorders provide information related to the “tap to tap” Arc Furnaces operation time. In this article, a heuristic analysis is performed for electric arc furnace operation. At a later stage of the investigation, an optimization of the operation is performed. Each step of the process is analyzed or put into operation according to the conditions of an expert. Under the specified operating conditions, furnace behavior is characterized, and the relationship between voltage levels in the secondary arc and the melting process is identified. Further, a search is carried out in the furnace s feeder, and the specific mechanics in the furnace for “Tap to Tap” decrease are identified. This analysis enables the proposal of a new optimization model, which considers dynamic programming. Part of the proposal is implemented in a 17-ton furnace, used for melting and refining.

Electric arc furnaces influence in power systems area

Power quality records provide information related to voltage and current waveforms and also deformation indicators, such as unbalance, and flicker. This disaggregation does not provide a global view of the degree of quality deterioration throughout the system. Valuations based on disaggregation of waveforms is inadequate in steel companies due to the fact that unbalances, flicker, and other deformation indicators are generated during operation. Thus, it is important to propose a definition to unify concepts related to waveform distortion in order to evaluate the connectivity of dynamic loads, such as electric arc furnaces. This paper proposes a new methodology of power quality distortion analysis using a dynamic visualization of the alteration produced by the connection in a steel company. This method uses the tensor concept of waveforms to generate a single parameter characteristic of the condition of power quality in three-phase systems.