The integration of Distributed Generators (DGs) into distribution systems (DSs) leads to more rel... more The integration of Distributed Generators (DGs) into distribution systems (DSs) leads to more reliable and efficient power delivery for customers. However, the possibility of bi-directional power flow creates new technical problems for protection schemes. This poses a threat to conventional strategies because the relay settings have to be adjusted depending on the network topology and operational mode. As a solution, it is important to develop novel fault protection techniques to ensure reliable protection and avoid unnecessary tripping. In this regard, Total Harmonic Distortion (THD) can be used as a key parameter for evaluating the grid’s waveform quality during fault events. This paper presents a comparison between two DS protection strategies that employ THD levels, estimated amplitude voltages, and zero-sequence components as instantaneous indicators during the faults that function as a kind of fault sensor to detect, identify, and isolate faults. The first method uses a Multip...
International Journal of Electrical and Computer Engineering Research
This work presents a literature review about control techniques for parallel connected power inve... more This work presents a literature review about control techniques for parallel connected power inverters under microgrid applications. Some control strategies, based on droop control for parallel inverters of distributed generation units in an ac distribution system will be presented in this work. Finally, an important method called Virtual Oscillating Control (VOC) is suggested for connecting voltage source inverters. Inverters are able to work in parallel with a constant-voltage constant frequency system, as well as with other inverters and also in standalone operation. The different power sources can share the load also under unbalanced conditions. Throughout this work several simulation results are presented in order to demonstrate the behaviour the behavior of the different control strategies tested.
IEEE 34th Annual Conference on Power Electronics Specialist, 2003. PESC '03.
In this paper, a new control scheme for parallel-connected inverters without communication wires ... more In this paper, a new control scheme for parallel-connected inverters without communication wires is presented. This wireless control technique is based on the well-known droop method, which consists of introducing P-ω and Q-V schemes into the inverters, in order to share properly the power drawn to the loads. In the literature, the droop method has been widely discussed in applications
Abstract In this paper, a new approach for the wireless control of parallel-connected uninterrupt... more Abstract In this paper, a new approach for the wireless control of parallel-connected uninterruptible power supplies is proposed. This method can perform the output-voltage frequency accuracy of the paralleled system, by using a transient droop characteristic. In ...
Abstract The aim of this paper is the application of feedback linearization techniques to a singl... more Abstract The aim of this paper is the application of feedback linearization techniques to a single-phase active power filter via a sliding mode control approach. The sliding control surfaces are designed by imposing a desired dynamic behavior on the system, which ...
The main difficulty to control an active filter is linked to the nature of the load, and especial... more The main difficulty to control an active filter is linked to the nature of the load, and especially when the load is capacitive. In this paper, to solve this problem, a sliding mode control is conceived by imposing a desired dynamics in the mains current. A passive filter in series with the load is introduced to reduce the instabilities due
2008 IEEE International Symposium on Industrial Electronics, 2008
As the grid code specifies, wind turbines have to remain connected to the grid at voltage levels ... more As the grid code specifies, wind turbines have to remain connected to the grid at voltage levels far below the nominal values. The improvement of wind turbine performance under such conditions has become a problem of general concern. However, this performance usually relies on conventional linear controllers that operate at network faults far off the nominal point for which they
IEEE 34th Annual Conference on Power Electronics Specialist, 2003. PESC '03.
In this paper, a new control scheme for parallel-connected inverters without communication wires ... more In this paper, a new control scheme for parallel-connected inverters without communication wires is presented. This wireless control technique is based on the well-known droop method, which consists of introducing P-ω and Q-V schemes into the inverters, in order to share properly the power drawn to the loads. In the literature, the droop method has been widely discussed in applications
Abstract In this paper, a new approach for the wireless control of parallel-connected uninterrupt... more Abstract In this paper, a new approach for the wireless control of parallel-connected uninterruptible power supplies is proposed. This method can perform the output-voltage frequency accuracy of the paralleled system, by using a transient droop characteristic. In ...
Abstract The aim of this paper is the application of feedback linearization techniques to a singl... more Abstract The aim of this paper is the application of feedback linearization techniques to a single-phase active power filter via a sliding mode control approach. The sliding control surfaces are designed by imposing a desired dynamic behavior on the system, which ...
The main difficulty to control an active filter is linked to the nature of the load, and especial... more The main difficulty to control an active filter is linked to the nature of the load, and especially when the load is capacitive. In this paper, to solve this problem, a sliding mode control is conceived by imposing a desired dynamics in the mains current. A passive filter in series with the load is introduced to reduce the instabilities due
2008 IEEE International Symposium on Industrial Electronics, 2008
As the grid code specifies, wind turbines have to remain connected to the grid at voltage levels ... more As the grid code specifies, wind turbines have to remain connected to the grid at voltage levels far below the nominal values. The improvement of wind turbine performance under such conditions has become a problem of general concern. However, this performance usually relies on conventional linear controllers that operate at network faults far off the nominal point for which they
Page 1. Copyright (c) 2010 IEEE. Personal use is permitted. For any other purposes, Permission mu... more Page 1. Copyright (c) 2010 IEEE. Personal use is permitted. For any other purposes, Permission must be obtained from the IEEE by emailing pubs-permissions@ieee.org. This article has been accepted for publication in a future issue of this journal, but has not been fully edited. ...
The integration of Distributed Generators (DGs) into distribution systems (DSs) leads to more rel... more The integration of Distributed Generators (DGs) into distribution systems (DSs) leads to more reliable and efficient power delivery for customers. However, the possibility of bi-directional power flow creates new technical problems for protection schemes. This poses a threat to conventional strategies because the relay settings have to be adjusted depending on the network topology and operational mode. As a solution, it is important to develop novel fault protection techniques to ensure reliable protection and avoid unnecessary tripping. In this regard, Total Harmonic Distortion (THD) can be used as a key parameter for evaluating the grid’s waveform quality during fault events. This paper presents a comparison between two DS protection strategies that employ THD levels, estimated amplitude voltages, and zero-sequence components as instantaneous indicators during the faults that function as a kind of fault sensor to detect, identify, and isolate faults. The first method uses a Multip...
International Journal of Electrical and Computer Engineering Research
This work presents a literature review about control techniques for parallel connected power inve... more This work presents a literature review about control techniques for parallel connected power inverters under microgrid applications. Some control strategies, based on droop control for parallel inverters of distributed generation units in an ac distribution system will be presented in this work. Finally, an important method called Virtual Oscillating Control (VOC) is suggested for connecting voltage source inverters. Inverters are able to work in parallel with a constant-voltage constant frequency system, as well as with other inverters and also in standalone operation. The different power sources can share the load also under unbalanced conditions. Throughout this work several simulation results are presented in order to demonstrate the behaviour the behavior of the different control strategies tested.
IEEE 34th Annual Conference on Power Electronics Specialist, 2003. PESC '03.
In this paper, a new control scheme for parallel-connected inverters without communication wires ... more In this paper, a new control scheme for parallel-connected inverters without communication wires is presented. This wireless control technique is based on the well-known droop method, which consists of introducing P-ω and Q-V schemes into the inverters, in order to share properly the power drawn to the loads. In the literature, the droop method has been widely discussed in applications
Abstract In this paper, a new approach for the wireless control of parallel-connected uninterrupt... more Abstract In this paper, a new approach for the wireless control of parallel-connected uninterruptible power supplies is proposed. This method can perform the output-voltage frequency accuracy of the paralleled system, by using a transient droop characteristic. In ...
Abstract The aim of this paper is the application of feedback linearization techniques to a singl... more Abstract The aim of this paper is the application of feedback linearization techniques to a single-phase active power filter via a sliding mode control approach. The sliding control surfaces are designed by imposing a desired dynamic behavior on the system, which ...
The main difficulty to control an active filter is linked to the nature of the load, and especial... more The main difficulty to control an active filter is linked to the nature of the load, and especially when the load is capacitive. In this paper, to solve this problem, a sliding mode control is conceived by imposing a desired dynamics in the mains current. A passive filter in series with the load is introduced to reduce the instabilities due
2008 IEEE International Symposium on Industrial Electronics, 2008
As the grid code specifies, wind turbines have to remain connected to the grid at voltage levels ... more As the grid code specifies, wind turbines have to remain connected to the grid at voltage levels far below the nominal values. The improvement of wind turbine performance under such conditions has become a problem of general concern. However, this performance usually relies on conventional linear controllers that operate at network faults far off the nominal point for which they
IEEE 34th Annual Conference on Power Electronics Specialist, 2003. PESC '03.
In this paper, a new control scheme for parallel-connected inverters without communication wires ... more In this paper, a new control scheme for parallel-connected inverters without communication wires is presented. This wireless control technique is based on the well-known droop method, which consists of introducing P-ω and Q-V schemes into the inverters, in order to share properly the power drawn to the loads. In the literature, the droop method has been widely discussed in applications
Abstract In this paper, a new approach for the wireless control of parallel-connected uninterrupt... more Abstract In this paper, a new approach for the wireless control of parallel-connected uninterruptible power supplies is proposed. This method can perform the output-voltage frequency accuracy of the paralleled system, by using a transient droop characteristic. In ...
Abstract The aim of this paper is the application of feedback linearization techniques to a singl... more Abstract The aim of this paper is the application of feedback linearization techniques to a single-phase active power filter via a sliding mode control approach. The sliding control surfaces are designed by imposing a desired dynamic behavior on the system, which ...
The main difficulty to control an active filter is linked to the nature of the load, and especial... more The main difficulty to control an active filter is linked to the nature of the load, and especially when the load is capacitive. In this paper, to solve this problem, a sliding mode control is conceived by imposing a desired dynamics in the mains current. A passive filter in series with the load is introduced to reduce the instabilities due
2008 IEEE International Symposium on Industrial Electronics, 2008
As the grid code specifies, wind turbines have to remain connected to the grid at voltage levels ... more As the grid code specifies, wind turbines have to remain connected to the grid at voltage levels far below the nominal values. The improvement of wind turbine performance under such conditions has become a problem of general concern. However, this performance usually relies on conventional linear controllers that operate at network faults far off the nominal point for which they
Page 1. Copyright (c) 2010 IEEE. Personal use is permitted. For any other purposes, Permission mu... more Page 1. Copyright (c) 2010 IEEE. Personal use is permitted. For any other purposes, Permission must be obtained from the IEEE by emailing pubs-permissions@ieee.org. This article has been accepted for publication in a future issue of this journal, but has not been fully edited. ...
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