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Author

Antonio Dell' Aquila

Bio: Antonio Dell' Aquila is an academic researcher from Instituto Politécnico Nacional. The author has contributed to research in topics: Islanding & AC power. The author has an hindex of 4, co-authored 4 publications receiving 270 citations.

Papers
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Proceedings ArticleDOI
01 Aug 2006
TL;DR: In this paper, an overview of the active methods used for islanding detection is presented, and the reported algorithms are carefully analyzed in their advantage and drawbacks and the considerations are validated by tests results obtained in accordance with the IEEE Std. 929-2000 procedure.
Abstract: For pt.I see ibid., p.420-5 (2006).This paper offers an overview of the active methods used for islanding detection. The inverter control algorithm is based on the use of harmonic compensators in order to create ideal working conditions (i.e. the PV-system produces a sinusoidal current and reject grid harmonics). This condition is the indispensable starting point to implement active islanding detection methods. In fact these methods are based on the perturbation of the ideal conditions (e.g. the injection of active/reactive power, the injection of current harmonics, or the insertion of an external capacitor). All the reported algorithms are carefully analysed in their advantage and drawbacks and the considerations are validated by tests results obtained in accordance with the IEEE Std. 929-2000 procedure

242 citations

Proceedings ArticleDOI
01 Jan 2005
TL;DR: In this article, a new anti-islanding method is proposed that exploits the natural sensitivity to disturbances of a grid voltage sensorless control to highlight the islanding condition of a distributed generation system.
Abstract: The detection of the islanding condition of a distributed generation system is crucial for safety reason, as discussed in IEEE Standards, and specifically required by some national codes Several anti-islanding methods have been investigated and classified as passive (measurement of the natural effects of islanding) and active (based on the measurement of the effects due to transients or harmonics deliberately introduced in the system) In case the power drained by the load matches the power generated by the DG inverter the effect of islanding are small and the passive detection methods fail However the active methods that have been developed to overcome these limits create disturbances that can interact with those generated by other DG systems In this paper a new anti-islanding method is proposed It exploits the natural sensitivity to disturbances of a grid voltage sensorless control to highlight islanding condition The adopted grid voltage sensorless control is adapted to a single-phase system with the use of resonant controllers on the basis of the internal model control law: a resonant controller-based observer results Then a Kalman-filter-based algorithm is used to detect the islanding condition on the basis of the energy mismatch between the estimated 3/sup rd/ and 5/sup th/ harmonics and the real ones Simulation and experimental results support the analysis

12 citations

Journal ArticleDOI
TL;DR: A new digital controller for UPQCs which allows the load current harmonics and reactive power to be compensated at the grid side while avoiding the effect of voltage dips, over-voltages and voltage harmonics on the local loads is proposed.
Abstract: Unified power quality conditioners (UPQCs) allow the mitigation of voltage and current disturbances that could affect sensitive electrical loads while compensating the load reactive power. Diverse control techniques have been proposed to evaluate the instantaneous output voltage of the series active power filter of the UPQC but, in most cases, these controllers only can compensate a kind of voltage disturbance. This paper proposes a new digital controller for UPQCs which allows the load current harmonics and reactive power to be compensated at the grid side while avoiding the effect of voltage dips, over-voltages and voltage harmonics on the local loads. The controller characteristics can be established on-line without changing its basic structure. The performance of the proposed controller has been evaluated through simulation tests.

9 citations

Proceedings ArticleDOI
TL;DR: In this article , the authors proposed a debridement of the infected area with removal of the sternal wires and partial or complete resection of the upper sternum, which is still a life threatening complication following cardiac surgery.
Abstract: Background: Deep sternal infection is still a life threatening complication following cardiac surgery. Current guidelines recommend radical debridement of the infected area with removal of the sternal wires and partial or complete resection of the sternum.

Cited by
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Journal ArticleDOI
TL;DR: The goal of this paper is to provide an overview of the open problems related to PV power processing systems and to focus the attention of researchers and industries on present and future challenges in this field.
Abstract: Power processing systems will be a key factor of future photovoltaic (PV) applications. They will play a central role in transferring, to the load and/or to the grid, the electric power produced by the high-efficiency PV cells of the next generation. In order to come up the expectations related to the use of solar energy for producing electrical energy, such systems must ensure high efficiency, modularity, and, particularly, high reliability. The goal of this paper is to provide an overview of the open problems related to PV power processing systems and to focus the attention of researchers and industries on present and future challenges in this field.

559 citations

Journal ArticleDOI
TL;DR: In this article, a comprehensive overview on important issues affecting the distribution system as a result of PV penetration is presented, including voltage fluctuation, voltage rise, voltage balance, and harmonics and their effect on the system.
Abstract: The solar energy generation has grown significantly in the past years. The importance of PV penetration in power system as a major element of renewable energy source has seen it being widely used on a global scale. Despite its promising success, PV penetration presents various issues and its impact on the distribution system has to address for seamless integration in the power system. In this paper, a comprehensive overview on important issues affecting the distribution system as a result of PV penetration is presented. Pertinent issues such as voltage fluctuation, voltage rise, voltage balance, and harmonics and their effect on the system are discussed in details. The islanding issues, which are of critical importance to the stability and integrity of the system, are also thoroughly reviewed. Details on different islanding techniques – remote and local techniques and their advantage and disadvantages are shown. Therefore, this paper can provide useful information and serve as a reference for researchers and utility engineers on issues to be considered with regards to PV penetration.

403 citations

Journal ArticleDOI
TL;DR: In this paper, a generalized closed-loop control (GCC) scheme was proposed for voltage source converters (VSCs) with LC or LCL output filters, which has a singleloop control of inverter output (voltage or current) and two parallel virtual impedance terms using additional measurements.
Abstract: In this paper, a generalized closed-loop control (GCC) scheme is proposed for voltage source converters (VSCs) with LC or LCL output filters. The proposed GCC scheme has a single-loop control of inverter output (voltage or current) and two parallel virtual impedance terms using additional measurements. The virtual impedance can be the equivalent internal impedance or external impedance (or both), depending on their control term and feedback variable selection. The internal impedance term is mainly responsible for providing desired damping to the filter circuit, and the external virtual impedance term can effectively adjust the converter system closed-loop output impedance. As each term in the GCC scheme can be controlled independently, the proposed GCC scheme has great flexibility and can easily realize and explain the performances of the traditional single- and multiloop control schemes and their different variations. Moreover, the GCC scheme provides a distinct physical meaning of each control term, which makes the control parameter tuning more straightforward and robust. Additionally, as shown in this paper, the proposed GCC scheme can tackle some traditionally challenging control objectives by avoiding the harmonics filtering or derivative terms. Experimental results from laboratory VSC prototypes are obtained to validate the proposed GCC scheme.

345 citations

Journal ArticleDOI
TL;DR: A two-current-loop control strategy, which includes grid-current outer loop and filter-capacitor-current inner loop, is adopted here to solve the problem of designing a controller for grid-connected LCL filters.
Abstract: LCL filters offer a better choice of attenuating switching frequency harmonics. However, in a grid-connected system, an LCL filter may cause resonance which is a disaster for the system's stability. In order to solve the problem, a two-current-loop control strategy, which includes grid-current outer loop and filter-capacitor-current inner loop, is adopted here. The implementation of this strategy is easy, but the tuning procedure is complex since the outer and inner controllers cannot cooperate well if the parameters of the controllers are not suitable. There is no literature which mentions a method to help give out accurate parameters of the controller. The difficulty of designing the controller is that only two feedbacks cannot provide complete information of a three-order LCL filter. A specific method is proposed in this paper to design the controller. The advantage of this method is to provide a way to maximize the utilization of the two feedbacks to get good system performance through parameter determination. The practicability of the method is tested by using bode diagram, and the antidistortion ability of the system is analyzed. Finally, experimental results verify the availability and correctness of the proposed method.

255 citations

Journal ArticleDOI
Canbing Li1, Cao Chi1, Yijia Cao1, Yonghong Kuang1, Long Zeng1, Baling Fang1 
TL;DR: In this article, performance indices and critical technique problems of islanding detection methods are discussed, and several performance indices, such as non-detection zone (NDZ), detection time, error detection ratio and power quality, are evaluated.
Abstract: Renewable energy generation is considered as an important approach to solve energy and environment problems in the future. Distributed generation technique is a primary way to utilize renewable energy. Microgrid integrated with different kinds of distributed resources can improve energy efficiency and reduce the negative impact on power grid. Microgrid may operate in grid-connected or islanding mode, running on quite different strategies. Effective islanding detection methods are indispensable to realize optimal operation of microgrid. In this paper, performance indices and critical technique problems are discussed. Islanding detection methods are also classified. The paper aims to discuss the improvement of several performance indices, including non-detection zone (NDZ), detection time, error detection ratio and power quality, to evaluate different detection methods. Effectiveness in multiple-inverter cases is also analyzed. According to the comparison upon the advantages and disadvantages of each method, the applicability is discussed, which may provide a reference for researchers to select islanding detection methods.

204 citations