Joan Bergas-Jane

Universitat Politècnica de Catalunya | UPC · Department of Electrical Engineering (DEE)

This paper presents a 2-level controller managing a hybrid energy storage solution (HESS) for the grid integration of photovoltaic (PV) plants in distribution grids. The HESS is based on the interconnection of a lead-acid battery pack and a supercapacitor pack through a modular power electronics cabinet. The inclusion of the HESS into the PV plant...

This paper presents a steady-state comparison of two methods that generate an orthogonal voltage system for a single-phase Phase-Locked Loop (PLL) structure: a widely accepted one based on a Second Order Generalized Integrator (SOGI) and a new one based on a All-Pass Filter (APF) with Lattice structure. Both methods are very attractive because of t...

Single-Phase Phase-Locked Loops (PLL) have become a crucial component of grid-tied power converters. PLL accuracy and fast response are important for control and protection purposes, especially in the presence of voltage harmonics and frequency variations. In this paper, a new PLL structure based on an Adaptive Notch Filter (ANF) is presented. This...

This paper proposes a novel Space Vector Pulse Width Modulation strategy extending conventional 2-D SVPWM strategies for its use in three-phase four-leg inverters. The methodology is based on the segregation of the zero sequence from any initial desired unbalance voltage set-points. In this way, the operation of the fourth leg is reserved to manage...

Electric Vehicles (EVs) have seen significant growth in sales recently and it is not clear how power systems will support the charging of a great number of vehicles. This paper proposes a methodology which allows the aggregated EV charging demand to be determined. The methodology applied to obtain the model is based on an agent-based approach to ca...

This paper proposes a charging/discharging process for electric vehicles according to mode 4, specifically based on the CHAdeMO protocol. These initiatives will enable acceptably fast charging of EVs. The proposal has been designed and implemented within the Endesa Novare Vehicle to Microgrid project. As a first stage of the project, the charge/dis...

A control scheme for Squirrel Cage Induction Generator (SCIG) based wind turbine cluster (or entire wind farm) connected by means of a single high voltage direct current-Voltage Source Converter (VSC-HVDC) is presented. The proposed scheme extends the SCIG vector control of a single wind turbine with a full power converter to a whole wind turbine c...

SUMMARY Phase-locked loop schemes are widely used in induction heating applications for controlling the converters. Most authors use total or partial analog solutions to implement the control schemes, which are less sturdy and flexible to changes than digital schemes. In this paper, an all-digital DSP-based PLL is presented. It has fewer variations...

Charging infrastructure for electric vehicles can impact significantly on distribution systems. Normal charging will be the usual way while fast charging has to be considered as a complement to this. Both charging processes represent a new load for distribution networks. The effect of both normal and fast charging are assesses. Management strategie...

This paper compares different cascaded and multilevel topologies to interface supercapacitors to a dc bus in regenerative braking applications. It is shown that the modular multilevel dc/dc converter (MMC) can benefit from both reduced voltage and increased frequency across the inductor to reduce its weight and volume when using phase shifting modu...

Magnetic ballast discharge lamp modeling has been extensively studied because these lamps can be an important source of harmonics. Discharge lamp models usually represent the arc voltage by a square waveform. However, this waveform can be far from actual arc voltages, which affects the accuracy of the lamp models. This paper investigates the actual...

In several three-phase installations, such as electrothermal and traction systems, single-phase loads are sometimes delta connected with reactances to reduce voltage unbalances. This delta-connected set is called the Steinmetz circuit. This work studies the design of this circuit to balance line currents consumed by single-phase loads. In contrast...

For the last years, PV (photovoltaic) generation has been having an important impact on LV (low voltage) and MV (medium voltage) grids in Spain, due to the increasing number of installations. As power monitoring of the generation is in most cases not required, utilities are forced to make assumptions on PV power generation in order to perform netwo...

Purpose – The aim of this paper is to simulate, test and evaluate an induction heating process considering the converter's performance. Design/methodology/approach – In case of continuous induction hardening processes, the load changes abruptly during the transition to Curie temperature, becoming significant considering the converter's behavior. I...

Regenerative braking is presented in many electric traction applications such as electric and hybrid vehicles, lifts and railway. The regenerated energy can be stored for future use, increasing the efficiency of the system. This paper outlines the benefits of the MMC (modular multilevel converter) in front of the cascaded or series connection of co...

Power electronics plays a key role in energy efficiency in electrical systems. Power electronics is the enabling technology for renewable energy sources, such as photovoltaic, wind energy and fuel cell systems, and others, where the injected energy is subjected to strong regulation in order not to perturb the grid. In distribution, power electronic...

This paper deals with the power generation efficiency analysis of a proposed offshore wind farm topology, consisting of a SLPC (single large power converter) that simultaneously controls a group of generators. This common converter can operate at a VF (variable frequency) or at a CF (constant frequency). The results are compared with the convention...

In this paper, a high-accuracy all-digital resolver- to-digital (R/D) converter is presented. The two basic components of a conventional tracking R/D converter, the phase detector and the loop filter, are software implemented by frequency-shift- ing techniques and a decoupled double synchronous reference frame-based phase-locked loop (DSRF-PLL). Th...

The life-cycle analysis (LCA) of photovoltaic (PV) systems is an important tool to quantify the potential environmental advantage of using solar technologies versus more traditional technologies, especially the ones relying on non-renewable fossil fuel sources.This work performs a life-cycle assessment on a 200kW roof top photovoltaic (PV) system w...

A control scheme for wind farms based on syn- chronous generators connected to a single power converter is presented. The scheme is applicable to HVDC interfaced offshore or remote wind farms. The proposed control scheme is based on computing the optimal wind farm electrical frequency depending on the different incoming wind speeds. The power conve...

This paper deals with the analysis of power, generated by offshore wind farms, connected to a single large power converter (SLPC), operating at variable frequency (VF) or at constant frequency (CF). The results are compared with a scheme widely used in current onshore wind farms, consisting of multiple power converters (MPC), one for each wind turb...

The paper deals with the multilevel converters control strategy for renewable energy resources integration in distribution grids. The proposed control scheme ensures the injection of the generated power in the distribution grid with fast dynamic response, while providing an additional active power filtering capability providing the required harmoni...

This paper presents a flexible control technique for connection of DG (distributed generation) resources to distribution networks, especially during ride-through on faulty grid. This strategy is derived from the abc/αβ and αβ/dq transformations of the ac system variables. The active and reactive currents injected by the DG source are controlled in...

This paper presents a methodology for the assessment of the impact of existing high voltage lines in urban areas. This methodology is based on the numeric evaluation of several impacts which are combined with weight factors. The novelty is that it opens up the possibility of citizen participation, basically in the way in which impacts and weighting...

The paper deals with permanent magnet synchronous generators based wind farms connected to a single power HVDC-VSC converter. A control scheme is proposed and validated by means of simulations. The proposed control scheme needs only current and voltage measurements in the wind farm transformer and seeks the maximum power generation using a variable...

This paper presents the intentional use of the Miller effect present in MOSFET devices to control a piezoelectric actuator. The Miller effect, normally neglected or minimized, can be useful to meet the dv/dt application requirements. A halfbridge converter is used as a power amplifier, where an external R-C network has been added to achieve the des...

Urban DC railway substations are growing in size due increasing capacity demand. Several challenges associated with the increase of power demand can be met using power electronics. The proposed system is based on DC-autotransformers and active rectifiers working similarly to those in 3-wire AC railway electrification system. Conventional simulation...

This paper deals with the control of doubly fed induction generators to ride through unbalanced voltage sags. A control strategy is proposed by choosing certain current reference values in the positive and negative sequences so that the torque and the DC voltage are kept stable during such unbalanced sags. Both rotor- and grid-side converters are c...

This paper presents a simulation work and control aspects of a Booster Dipole magnet power supply to a light source. Description of structure, operation of the structure and synchronous rectification Buck converter are discussed. Voltage and Current mode controllers for one-quadrant and two-quadrant converters are proposed. Better performance resul...

The present work deals with the development and control of a converter to drive piezoelectric actuators. Due to the piezoelectric load specification, a half-bridge converter is proposed. Such a converter is analyzed considering charging and discharging modes. The converter is controlled by means of a sliding mode control strategy, employing two dif...

This paper analyzes the sensitivity of DC adjustable-speed drives to balanced and unbalanced voltage sags. The influence of sag type, depth, duration and phase-angle jump on DC drives is studied. The control of the DC drive has been taken into account to understand drive behavior in the presence of voltage sags. Two working modes of the DC motor ar...

Purpose – This paper seeks to describe why PLC's development tools can be used in the programming of C‐programmed microcontrollers, and an exhaustive methodology to compile Graphe Fonctionnel de Commande Etapes‐Transitions (GRAFCET) specifications into C‐code. Design/methodology/approach – This paper introduces an exhaustive methodology to transla...

This paper presents a frequency estimation methodology in a single-phase voltage signal using adaptative notch filters. The simulations are realized using the Simulink toolbox of MatLab 7.0.4 and executed on a DSP TMS320F2808 platform of Texas instruments. We observe the behavior of PLL in presence of frequency values changes, voltage sags and THD...

Conventional electric field mill designs are not able to measure quasi-static atmospheric electric fields in the vicinity of high-voltage power systems. The electric fields generated by such power systems produce severe perturbations to the quasi-static background electric field. Filtering of these perturbations by the field mill circuitry seems to...

In the above titled paper (ibid., vol. 22, no. 2, pp. 584-592, Mar 07), the full version of Fig. 8 was not displayed. The correct version is presented here.

Electrical energy distribution repayment models applied in several countries has been also the aim of regulatory changes and critics. This article describes repayment models of electrical energy distribution in economies with liberalized power markets, and it also describes the advantages and problems that they have presented according to the point...

This paper deals with a crucial aspect in the control of grid-connected power converters, i.e., the detection of the fundamental-frequency positive-sequence component of the utility voltage under unbalanced and distorted conditions. Specifically, it proposes a positive-sequence detector based on a new decoupled double synchronous reference frame ph...

This paper deals with the modeling of a piezoelectric actuator taking into account the effect of hysteresis. The model used for the description of the hysteresis phenomenon is that of Bouc–Wen. This model has been used extensively in various engineering areas during the last decade. The Bouc–Wen model consists in a first-order nonlinear state equat...

This paper introduces a chemical process automation virtual laboratory to teach programmable logic component (PLC) programming to chemical engineering students. The virtual laboratory was used in the practice part of an electrical engineering course and focuses on the basic automation of chemical processes. The students have been provided with the...

It is necessary to have tools that allow the regulator, or the distributor, to fix the quality goals according to the electrical system of the area, taking care about the special characteristics that every distribution company has in front of the others. This article presents a methodology which allows having a simple tool for making this compariso...

This paper deals with one of the most important issues in the control of grid-connected converters, which is the detection of the positive sequence fundamental component of the utility voltage. The study carried out in this paper conducts to a fast, precise, and robust positive sequence voltage detector offering a good behavior, even if unbalanced...

In this paper, an all-digital resolver-to-digital converter is presented. Using oversampling and frequency shifts techniques, along with a synchronous rotating reference frame based PLL, an accurate and fast tracking resolver-to-digital converter is presented. With the use of all these combined techniques, and using a standard DSP with a 10 bits AD...

Fair weather electric fields are disturbed when a thundercloud is present. The evolution of electrification before first lightning strike gives one enough time to act against possible lightning damage. Surface irregularities and nearby objects disturb the atmospheric electric field, so each place has a particular behaviour when evaluating the risk...

Electrostatic field mill has been large employed by scientist for charge estimation, concentration, storm characterization etc. in not very much cases field mills are employed as a part of a protection system or as a lightning hazard warning system. One reason is the particular behaviour of the electrostatic field at any point of measurement, local...

This paper presents an alternative three-phase four-wire converter for active power filter applications. The topology of this converter consists of four switch-legs, and it uses a "split-capacitor" in the DC-bus. In this converter, three legs are destined to control the injected currents in utility lines, while the fourth leg assures a balanced vol...

This paper presents a positive sequence voltage detector based on a new "synchronous double reference frame PLL" (SDRF-PLL). This PLL exhibits a fast, precise and robust behavior under unbalanced utility conditions. When amplitude and phase of the positive sequence source voltage are known, various compensation strategies are feasible for the contr...

The perfection of sine wave power supply is always assumed, that is to say, voltage power supply has 50 or 60 Hz perfect sinusoidal waveform and its root mean square value is the rated one. It is known that electrical companies cannot supply this perfect kind of waveform, though in normal conditions they are within the limits imposed by regulations...

Virtual laboratories are being used in automation design for integrator systems. Since the use of IEC 61131-3 languages is standardised in the industrial automation programming, the authors consider introducing these languages in the develop of virtual laboratories. The Virtual Laboratory of Automation at the University of Oriente (Cuba) works towa...

The paper presents a dedicated hardware interfacing an optical incremental encoder and DSP-controlled motion system. Different velocity sensing techniques and methods are discussed. One of them is chosen and implemented, fulfilling the main objectives proposed. The first objective is to reserve the computational power of the DSP for control tasks,...

This paper presents the development and results obtained from an active control system of the energy in low-voltage networks subjected to disturbances, and in which the maintenance of the anticipated voltage margins is an important factor. This system, due to its good performance in a dynamic regime, is a rapid voltage stabiliser that insulates the...