Person:
Marroyo Palomo, Luis

person.page.identifierURI

https://academica-e.unavarra.es/handle/2454/49511

Last Name

Marroyo Palomo

First Name

Luis

person.page.departamento

Ingeniería Eléctrica, Electrónica y de Comunicación

person.page.instituteName

ISC. Institute of Smart Cities

ORCID

0000-0002-8344-8374

person.page.upna

495

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Now showing 1 - 10 of 30

Open Access
Design methodology for the frequency shift method of islanding prevention and analysis of its detection capability
(Wiley, 2005) Sanchis Gúrpide, Pablo; Marroyo Palomo, Luis; Coloma, Javier; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Islanding protection is one of the most important sources of discrepancy in gridconnected photovoltaic systems. Even when islanding is not very likely to happen, regulations demand the photovoltaic inverters to implement effective protection methods. Due to its several advantages, the frequency shift method of islanding prevention, commonly known as Sandia Frequency Shift, is one of the most important active methods. This method implements a positive feedback of the frequency that tends to move it outside the trip limits in case of islanding. The method shows a very high detection capability, which depends on both the values of the method parameters and the characteristics of the load that remains in the same power section after islanding. This paper develops a mathematical analysis of the Sandia Frequency Shift method and proposes a new methodology to design its parameters as a trade-off between the detection capability, which is evaluated as a function of the load characteristics, and the distortion that the method could introduce in the grid as a consequence of transitory frequency disturbances. The ability of this methodology to design the method parameters and achieve the highest detection capability is satisfactorily proved by means of both simulation and experimental results on a commercial photovoltaic inverter that implements the method once its parameters have been designed with the proposed methodology.
Open Access
An energy management system design using fuzzy logic control: smoothing the grid power profile of a residential electro-thermal microgrid
(IEEE, 2021) Arcos Avilés, Diego; Pascual Miqueleiz, Julio María; Guinjoan Gispert, Francesc; Marroyo Palomo, Luis; García Gutiérrez, Gabriel; Gordillo, Rodolfo; Llanos, Jacqueline; Sanchis Gúrpide, Pablo; Motoasca, Emilia; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
This work deals with the design of a Fuzzy Logic Control (FLC) based Energy Management System (EMS) for smoothing the grid power prole of a grid-connected electro-thermal microgrid. The case study aims to design an Energy Management System (EMS) to reduce the impact on the grid power when renewable energy sources are incorporated to pre-existing grid-connected household appliances. The scenario considers a residential microgrid comprising photovoltaic and wind generators, at-plate collectors, electric and thermal loads and electrical and thermal energy storage systems and assumes that neither renewable generation nor the electrical and thermal load demands are controllable. The EMS is built through two low-complexity FLC blocks of only 25 rules each. The first one is in charge of smoothing the power prfile exchanged with the grid, whereas the second FLC block drives the power of the Electrical Water Heater (EWH). The EMS uses the forecast of the electrical and thermal power balance between generation and consumption to predict the microgrid behavior, for each 15-minute interval, over the next 12 hours. Simulations results, using real one-year measured data show that the proposed EMS design achieves 11.4% reduction of the maximum power absorbed from the grid and an outstanding reduction of the grid power profile ramp-rates when compared with other state-of-the-art studies.
Open Access
Comparison of linear and and small-signal models for inverter-based microgrids
(IEEE, 2014) Urtasun Erburu, Andoni; Sanchis Gúrpide, Pablo; Marroyo Palomo, Luis; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Frequency and voltage regulation in droop-based microgrids is generally modeled using small-signal analysis. In order to ensure accuracy, existing models do not decouple real and reactive power responses. However, the models become complicated and hide the real decoupled dynamics. This paper proposes a simple linear model which makes it possible to discern the different dynamic properties and to readily design the control parameters. The proposed model is validated by comparison with an accurate small-signal model and by simulation results. The effect of not considering the load is also evaluated.
Open Access
DC capacitance reduction in three-phase photovoltaic inverters by using virtual impedance emulation
(IEEE, 2019) Urtasun Erburu, Andoni; Sanchis Gúrpide, Pablo; Marroyo Palomo, Luis; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
DC voltage regulation in grid-connected three-phase PV inverters is a fundamental requirement. In order to reduce the influence of the PV non-linear behavior and ensure stability in the whole operating range, the input capacitance in high-power inverters is currently oversized, thus increasing the converter cost. This paper proposes a control method which emulates a virtual impedance in parallel with the PV generator, making it possible to reduce the capacitance by a factor of 5. Simulation results confirm that the proposed control is stable and fast enough in the whole operating range with such a small capacitor.
Open Access
Influence of the power supply on the energy efficiency of an alkaline water electrolyser
(Elsevier, 2009) Ursúa Rubio, Alfredo; Marroyo Palomo, Luis; Gubía Villabona, Eugenio; Gandía Pascual, Luis; Diéguez Elizondo, Pedro; Sanchis Gúrpide, Pablo; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Ingeniería Mecánica, Energética y de Materiales; Mekanika, Energetika eta Materialen Ingeniaritza; Química Aplicada; Kimika Aplikatua; Gobierno de Navarra / Nafarroako Gobernua
Electric energy consumption represents the greatest part of the cost of the hydrogen produced by water electrolysis. An effort is being carried out to reduce this electric consumption and improve the global efficiency of commercial electrolysers. Whereas relevant progresses are being achieved in cell stack configurations and electrodes performance, there are practically no studies on the effect of the electric power supply topology on the electrolyser energy efficiency. This paper presents an analysis on the energy consumption and efficiency of a 1 N m3 h1 commercial alkaline water electrolyser and their dependence on the power supply topology. The different topologies of power supplies are first summarised, analysed and classified into two groups: thyristor-based (ThPS) and transistor-based power supplies (TrPS). An Electrolyser Power Supply Emulator (EPSE) is then designed, developed and satisfactorily validated by means of simulation and experimental tests. With the EPSE, the electrolyser is characterised both obtaining its I–V curves for different temperatures and measuring the useful hydrogen production. The electrolyser is then supplied by means of two different emulated electric profiles that are characteristic of typical ThPS and TrPS. Results show that the cell stack energy consumption is up to 495 W h N m3 lower when it is supplied by the TrPS, which means 10% greater in terms of efficiency.
Open Access
Effect of the inner current loop on the voltage regulation for three-phase photovoltaic inverters
(IEEE, 2020) Urtasun Erburu, Andoni; Sanchis Gúrpide, Pablo; Marroyo Palomo, Luis; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
In three-phase grid-connected PV inverters, regulating the input voltage is a fundamental requirement. In order to reduce the influence of the PV non-linear behavior and ensure stability in the whole operating range, the input capacitance is currently oversized. This paper reveals the important effect of the inner current loop in the voltage stability and proposes to use a Proportional (P) controller instead of a PI controller. If tuned following the guidelines provided in this paper, the P controller makes it possible to design a stable voltage loop without increasing the input capacitance, thus reducing the converter cost.
Open Access
On the stability criteria for inverter current control loops with LCL output filters and varying grid impedance
(IEEE, 2017) Lumbreras Magallón, David; Barrios Rípodas, Ernesto; Ursúa Rubio, Alfredo; Marroyo Palomo, Luis; Sanchis Gúrpide, Pablo; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
The use of LC and LCL filters and grid impedance variations are creating new challenges on the controller design for current control loops of photovoltaic and wind turbine inverters. In the design process, stability criteria such as Bode and revised Bode are commonly used. This paper analyses the limitations of Bode and revised Bode criteria to reliably determine stability and proposes a sufficient and necessary stability criterion, based on the Nyquist criterion, but that makes use of the Bode diagram. The proposed criterion, named generalized Bode criterion, is always reliable and helps the controller design. Relative stability in complex control loops is also studied and a relative stability analysis is proposed. Finally, the generalized Bode criterion and the proposed relative stability analysis are illustrated with a practical example in which a PI is designed in order to guarantee stability and achieve relative stability.
Open Access
Control of a photovoltaic array interfacing current-mode-controlled boost converter based on virtual impedance emulation
(IEEE, 2019) Urtasun Erburu, Andoni; Samanes Pascual, Javier; Barrios Rípodas, Ernesto; Sanchis Gúrpide, Pablo; Marroyo Palomo, Luis; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
Due to the nonlinear characteristics of a photovoltaic (PV) array, its regulation is highly dependent on the operating point. Focusing on a dc-dc boost converter, this paper first shows how the PV voltage and inductor current controls are affected by the PV array. It then proposes to emulate an impedance virtually connected to the PV array, making it possible to greatly improve the control robustness. Thanks to the proposed strategy, the crossover frequency variation for the whole operating range is reduced from 42 times for the traditional control to 3.5 times when emulating parallel resistance or to 1.4 times when emulating series and parallel resistances, all with simple implementation. Experimental results with a commercial PV inverter and a 4-kWp PV array validate the theoretical analysis and demonstrate the superior performance of the proposed control.
Open Access
On the testing, characterization, and evaluation of PV inverters and dynamic MPPT performance under real varying operating conditions
(Wiley, 2007) Sanchis Gúrpide, Pablo; López Taberna, Jesús; Ursúa Rubio, Alfredo; Gubía Villabona, Eugenio; Marroyo Palomo, Luis; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
The increasing number of photovoltaic inverters that are coming on to the PV marketstresses the need to carry out a dynamic characterization of these elements and theirmaximum power point tracking (MPPT) algorithms under real operating conditions.In order to make these conditions repeatable at the laboratory, PV array simulatorsare used. However, actual simulators, including the commercial simulators, recreateonly a single or small set of PV array characteristic curves in which quite commonlytheoretical calculations are included in order to simulate irradiance and temperatureartificial variations. This is far from being a recreation of the real and long dynamicbehavior of a PVarray or generator. The testing and evaluation of the performance ofPV inverters and MPPT algorithms has to be carried out when the PV system movesdynamically according to real operating conditions, including processes such asrapidly changing atmospheric conditions, partial shadows, dawn, and nightfall. Thispaper tries to contribute to the analysis of this problem by means of an electronicsystem that both measures the real evolution of the characteristic curves of PVarraysat outdoor operation and then recreates them at the laboratory to test PV inverters.This way the equipment can highlight the different performances of PV inverters andMPPT techniques when they operate under real operating conditions. As an example,two commercial inverters are tested and analyzed under the recreated behavior of aPV generator during 2 singular days that include processes of partial shading and fastirradiance variations.
Open Access
Implementation and control of a residential electrothermal microgrid based on renewable energies, a hybrid storage system and demand side management
(MDPI, 2014) Pascual Miqueleiz, Julio María; Sanchis Gúrpide, Pablo; Marroyo Palomo, Luis; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua
This paper proposes an energy management strategy for a residential electrothermal microgrid, based on renewable energy sources. While grid connected, it makes use of a hybrid electrothermal storage system, formed by a battery and a hot water tank along with an electrical water heater as a controllable load, which make possible the energy management within the microgrid. The microgrid emulates the operation of a single family home with domestic hot water (DHW) consumption, a heating, ventilation and air conditioning (HVAC) system as well as the typical electric loads. An energy management strategy has been designed which optimizes the power exchanged with the grid profile in terms of peaks and fluctuations, in applications with high penetration levels of renewables. The proposed energy management strategy has been evaluated and validated experimentally in a full scale residential microgrid built in our Renewable Energy Laboratory, by means of continuous operation under real conditions. The results show that the combination of electric and thermal storage systems with controllable loads is a promising technology that could maximize the penetration level of renewable energies in the electric system.