J. R. Vázquez

Universidad de Huelva | UHU · Departamento de Ingeniería Eléctrica y Térmica, de Diseño y Proyectos

In this work, a computer tool developed in Matlab is presented for process control in real time. The Matlab/Simulink Embedded Code toolbox allows the programming of different commercial acquisition and control cards. In addition, it is easy to supervise the practical cases implemented both from the cards commercial interfaces and from Matlab/Simuli...

Nowadays, the promotion of renewable energy sources is a necessity. Technically, the increase of the renewable penetration in the power system (PS) is a challenge. One solution for this problem is the use of self-controlled microgrids (smartgrid, SG). In this work, the design of an algorithm to optimal manage the SG energy through the power inverte...

The promotion of the distributed generation and the photovoltaic (PV) energy great potential put this technology in the spotlight of investors. Thus, the optimization of its efficiency is made a priority. In this paper, a complete and versatile remote controller (C&VRC) for PV systems is presented, scalable to any kind and size of installations (wi...

Grid-connected photovoltaic (PV) systems are designed to provide energy to the grid. This energy transfer must fulfil some requirements such as system stability, power quality and reliability. Thus, the aim of this work is to design and control a grid-connected PV system via wireless to guarantee the correct operation of the system. It is crucial t...

An efficient monitoring and control system for solar photovoltaic modules, which combines the use of a non-linear MPPT backstepping controller with a custom wireless sensor network (WSN) has been developed. The infrastructure consists of a wireless smart photovoltaic system (WSPS) and a wireless centralized control system (WCC). The data of sensing...

The aim of a photovoltaic (PV) system’s control is the extraction of the maximum power even if the irradiance, the temperature, or the parameters vary. To do that, a maximum power point tracking (MPPT) algorithm is required. In this work, a sliding control is designed to regulate the PV modules’ output voltage and make the panel work at the maximum...

Maximum power point tracking (MPPT) algorithms should track and extract the maximum power from photovoltaic (PV) systems under any environmental conditions. Most of conventional MPPT methods are able to reach the maximum point when there is only one peak in the P–V characteristic curve but they fail when the solar cells are affected by partial shad...

This paper presents a nonlinear method to control a DC-DC converter and track the Maximum Power Point (MPP) of a Photovoltaic (PV) system. A backstepping controller is proposed to regulate the voltage at the input of a buck-boost converter by means of Lyapunov functions. To make the control initially faster and avoid local maximum, a regression pla...

The identification of voltage and current harmonic distortion and voltage unbalance sources is one of the main problems in electric distribution systems. In order to overcome it, in this paper the use of two novel indices is proposed. On the one hand, the Load Characterization Index (LCI) is suggested to calculate the harmonic distortion introduced...

Backstepping controllers are obtained for distributed hybrid photovoltaic (PV) power supplies of telecommunication equipment. Grid-connected PV-based power supply units may contain dc-dc buck-boost converters linked to single-phase inverters. This distributed energy resource operated within the self-consumption concept can aid in the peak-shaving s...

This paper presents a comparative analysis of control methods to extract the maximum power and to track the maximum power point (MPP) from photovoltaic (PV) systems under changeable environmental conditions. The PV system consists of a solar module and a DC/DC converter, in this case a buck-boost converter, connected to a load. The maximum power po...

The increase in non-linear loads in the electrical network deteriorates the voltage waveform quality. One of the most used methods to correct the quality lack is to use shunt, series or mixed topologies of active power filters. Mixed filters can compensate loads that generate voltage harmonics and current harmonics, but the economic investment is h...

SUMMARY Voltage unbalance is one of the main problems in electric distribution systems. The standards limit the level of voltage unbalance in a specific point without considering the agent of the network that produces it. Nevertheless, the identification of the responsible for system unbalance may be very important, for example, to establish the mo...

This work presents a new control method to track the maximum power point of a grid-connected photovoltaic (PV) system. A backstepping controller is designed to be applied to a buck-boost DC-DC converter in order to achieve an optimal PV array output voltage. This nonlinear control is based on Lyapunov functions assuring the local stability of the s...

This paper presents a new nonlinear control method to regulate the voltage at the output of a DC-DC converter so as to achieve the maximum power point (MPP) of a photovoltaic (PV) system. The proposed adaptive backstepping controller of the system, based on Lyapunov functions to ensure locally stability, is applied to a buck-boost converter. A regr...

This paper presents a Photovoltaic Active Power Line Conditioner, a device designed to extract the maximum power of a photovoltaic (PV) system and to compensate the nonlinear and unbalanced loads of the electrical power systems. The grid-connected PV systems require DC-DC and DC-AC power converters to maximize the generated PV power and to inject a...

Voltage unbalance is one of the main problems in electric distribution system. The Standards limit the level of voltage unbalance in a specific point without considering its origin. Nevertheless, it may be important in different aspects. For example, to establish the most suitable procedure to mitigate the voltage and/or current unbalance or to ide...

Along the last years, the practical use of active filters to mitigate harmonics has been extended in electric power systems. Different configurations of series active filters versus shunt active filters have been proposed, among them, hybrid topolo-gies which combine active and passive filters. Nevertheless, there is not any clear accordance about...

Along the last years, the practical use of active filters to mitigate harmonics has been extended in electric power systems. Different configurations of series active filters versus shunt active filters have been proposed, among them, hybrid topologies which combine active and passive filters. Nevertheless, there is not any clear accordance about t...

Along the last years, the practical use of active filters to mitigate harmonics has been extended in electric power systems. Different configurations of series active filters versus shunt active filters have been proposed, among them, hybrid topologies which combine active and passive filters. Nevertheless, there is not any clear accordance about t...

This paper presents an efficient strategy control to maximize the power flow from a photovoltaic array to a stand-alone AC load. The photovoltaic power interface circuit incorporates a buck-boost converter and a full-bridge inverter. The buck-boost operates at high switching frequency and the full-bridge inverter operates at low frequency of 50 Her...

A control algorithm is proposed for a three-phase hybrid power filter constituted by a series active filter and a passive filter connected in parallel with the load. It is based on the dual formulation of the vectorial theory of instantaneous reactive power, so that the voltage waveform injected by the active filter is able to compensate the reacti...

In this paper, a maximum power point tracker method using sliding mode control for a photovoltaic system is presented. The system includes a photovoltaic array, a DC/DC converter and a DC/AC inverter connected to a load. The designed control regulates the converter output voltage and it maximizes the power generated by the photovoltaic array. To ob...

This paper proposes a control strategy of a Maximum Power Point Tracking (MPPT) of a photovoltaic (PV) system. The system includes a photovoltaic array, a DC/DC converter and a DC/AC inverter connected to a load. The proposed strategy is based on the sliding mode control and it allows a direct control of power converter. The stability as well as th...

The systematic use of Active Power Filters, APFs, to compensate nonlinear loads, has extended the use of the instantaneous reactive power theory. Originally, the p-q theory appeared; it obtained constant instantaneous power in the source side after compensation. Later, other formulations have been developed. They have allowed different compensation...

A control algorithm is proposed for a three-phase hybrid power filter constituted by a series active filter and a shunt passive filter. The control strategy is based on the dual formulation of the vectorial theory of electrical power, so that the voltage waveform injected by the active filter is able to compensate the reactive power, to eliminate h...

The original instantaneous reactive power theory or p–q theory has been systematically used in the control of active power filters (APFs). When the APF is connected in parallel to a non-linear and unbalanced load, the p–q theory application has allowed a compensation strategy named constant power to be obtained. This means that, after the APF conne...

The active power filters in series connection or series APF, are static compensation systems based on an electronic converter PWM (Pulse Width Modulation). The systematic use of series APFs in the power systems allows the elimination of the harmonics caused by specific loads named voltage source harmonic loads. To obtain this compensation objective...

A new control algorithm for a hybrid power filter constituted by a series active filter and a passive filter connected in parallel with the load is proposed. The new control strategy is based on the dual formulation of the vectorial theory of electric power, so that the signal injected by the active filter is able to compensate the reactive power a...

The original instantaneous reactive power or p-q theory has been used in a systematic way in the control of active power niters (APFs). When the APF is switched in parallel to a nonlinear and unbalanced load, the application of p-q theory allows a constant power compensation strategy. This means that after the APF connection, the supply instantaneo...

The control strategy derived from the instantaneous reactive power theory is one of the most commonly used in the Active Power Filters (APFs). For the last decades other formulations have been developed in order to achieve compensation objectives different to the proposed in the original one. Nevertheless, all of them can be only applied to three-p...

A new control algorithm for a hybrid filter formed by a series active filter and a passive filter connected in parallel with the load is proposed. The new control strategy is based on the dual formulation of the vectorial theory of electric power, so that the signal injected by the active filter is able to compensate the reactive power and the harm...

Nowadays, the active power filters, APFs, can be used as apractical solution to solve the problems caused by the lack of electric power quality, EPQ. The emerging technology of power-electronic devices and the new developments in digital signal processing, DSP, have made possible its practical use. These power filters can fully compensate the nonli...

The series active filters are used to compensate loads of the kind voltage harmonics source. In this paper three different control strategies have been applied to a series active filter. The first is based on that the filter voltage must be proportional to the harmonic of the source current. With the second strategy the filter voltage must be equal...

The apparent power and the derived power factor are two of the quantities of the biggest use and application inside the Electric Engineering. However, nowadays it continues staying the controversy on their definitions and more appropriate meaning in the most general situations in unbalance and distortion, and unequal resistances in the distribution...

One of the most common strategies used in the Active Power Filters (APFs) control is the derived from the instantaneous reactive power theory. Since its publication, a lot of others formulations have been developed in order to achieve compensation objectives different of the proposed in the original one. Nevertheless, all those formulations present...

Today, there is an increase of harmonic pollution in electrical systems due to the use of nonlinear loads. Thus, the current and voltage waveforms are nonsinusoidal. The active power-line conditioners (APLCs) are used to compensate the generated harmonics and to correct the load power factor. In this paper, a new APLC control design based on artifi...

In this paper, a hybrid passive-active power filter is proposed to compensate the non-linear loads in electrical power systems. The main compensation target is to mitigate the load current harmonics. An active power filter can be used to eliminate the load current harmonics, but it is a high cost solution. The use of passive filters are a more econ...

A combined system of shunt passive and series active filter for a four-wire three-phase system has been designed and simulated with Matlab/Simulink. The system combined mitigates the source current harmonics and compensates also unbalance voltages reducing the problems of using only a shunt passive filter. Therefore, a new control method based in t...

For three-phase four-wire circuits, two compensation criteria have been established: one based on the instantaneous value concept and the other on the average value concept. Thus, according to the instantaneous value concept the non instantaneous power current is reduced, without altering the instantaneous active power. According to the average val...

A method for controlling an active power filter using neural networks Is presented. Currently, there is an increase of voltage and current harmonics in power systems, caused by nonlinear loads. The active power filters (APFs) are used to compensate the generated harmonics and to correct the load power factor. The proposed control design is a pulse...

A new design method for the control implementation of a combined series-shunt active power filter (load compensation active conditioner, LCAC) for electrical power quality improvement is proposed. This active conditioner allows to cancel source voltage harmonics, to symmetrize the supply voltage, and to eliminate current harmonics and reactive/unba...

In this paper, a new method to control an active power line conditioner (APLC) using neural networks is presented. Actually, there is an increase of voltage and current harmonics in power systems, caused by nonlinear loads. The APLCs are used to compensate the generated harmonics and to correct the load power factor. The proposed control design is...

For three-phase four-wire circuits, two compensation criteria are possible: one based on the instantaneous value concept and the other on the average value concept. Thus, according to the first method the noninstantaneous power current is reduced, without altering the instantaneous active power (time-instantaneous compensation, TIC). On the other o...

A new control method for active power filters (APF) using neural networks is presented. It is pulse width modulation control (PWM) designed with two blocks that include neural networks. The first one includes adaptive networks that estimate the reference compensation current; adaptive linear neurons (Adaline) were used. The second one includes a fe...

A set of computer simulation models for electric power converters is presented. Converters can be analyzed by means of its input-output relationships determined by their transfer function. In this way each converter acts as a multiport network with which an equivalent circuit with controlled sources is associated. Four types of converters are propo...

Distorted voltage and current waveforms is one of the problems associated to electric power quality. Continuous use of non-linear loads provokes the existence of voltage waveforms with a high distortion. Thus, it is necessary to know the responsible of this problem by means of the commonly named distortion sources identification. In this paper, the...

1. Brief introduction The analysis of power quality in electrical power systems includes the study of transient disturbances as frequency variations, sags, swells, flicker or interruptions, (1-3). In this paper, a measurement system of some transient disturbances based on Artificial Neural Networks will be presented. A feedforward Artificial Neural...

A new control design of an Active Power Line Conditioner (APLC) for unbalanced/distorted electrical power system compensation is presented. The APLC is built by an dc-ac power converter and a control circuit. In this paper, the control circuit is a new design based in two types of artificial neural networks (ANNs). An adaptive linear neuron (ADALIN...

Resumen Se presenta el diseño del control de un acondicionador activo de potencia (Active Power Line Conditioner, APLC) basado en la combinación de dos tipos de redes neuronales. La primera red efectúa una estimación adaptativa de las señales de consigna a través de neuronas Adaline (ADAptive LInear NEuron). La segunda es una red multicapa entrenad...

Resumen En este trabajo se estudia el comportamiento de distintos compensadores de potencia de conexión paralela para la mitigación de armónicos de corriente en cargas trifásicas no lineales. Conocido el espectro armónico de la intensidad de una carga, el uso de filtros pasivos sintonizados a los armónicos de interés ofrecen una solución económica...

Acknowledgments This work was supported by the 'Comision Interministerial de Ciencia y Tecnología (CICYT)' of the Spanish Minister of Education and Culture. It is part of a project covering aspects of power quality measurements, active power filters and instantaneous compensation of non-linear loads. Abstract In three-phase four-wire systems, two c...