EPE Association: EPE 2020 - DS3j-2: DC Grids, Hybrid DC Circuit breakers, Real-Time Simulation and Mock-ups

EPE 2020 - DS3j-2: DC Grids, Hybrid DC Circuit breakers, Real-Time Simulation and Mock-ups
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 06: Grids, Smart Grids, AC & DC > EPE 2020 - DS3j-2: DC Grids, Hybrid DC Circuit breakers, Real-Time Simulation and Mock-ups

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   Fault detection and classification based on deep learning in LVDC off-grid system
By Iurii DEMIDOV [View]
[Download]

Abstract: The integration of information and communication technologies (ICT) into energy power systems provides new applications and possibilities for grid control, operation, and protection. In this paper, asmart self-sustained off-grid concept based on photovoltaics- and battery energy storage system andlow-voltage direct current (LVDC) power distribution network is studied. Due to small electrificationand poor internet coverage, Sub-Saharan Africa is the target area of the concept realization. Focusing on the application of deep learning, this research presents new approaches to the power system's protection, as fault detection and classification are one of the most essential LVDC electricity distribution issues.

   Feasibility Study of a Superconducting Power Filter for HVDC grids
By Loic QUEVAL [View]
[Download]

Abstract: A new application of high temperature superconducting technology for HVDC grids is introduced. The device referred to as "superconducting power filter" (ScPF) aims at increasing the stability of HVDC grids by adding a current-dependent resistance to the grid. In comparison with other stabilization techniques, a ScPF achieves a fully passive stabilization with virtually no losses in nominal operation. To clarify its feasibility for HVDC grids, the HVDC grid test system DCS1 proposed by CIGRE B4 is considered. Using an electrical-thermal model of the device, the stability of the DC grid is numerically assessed depending on the design parameters of the device. The first steps towards an experimental proof of concept are presented.

   Modelling and Experimental Validation of a Pole-To-Ground Protection Device in Low Voltage DC Microgrids
By Leonie HALLEMANS [View]
[Download]

Abstract: Over the past years, the scientific interest in Low Voltage DC grids as an alternative to traditional LVAC grids has been growing steadily. This is caused by the fact that the amount of renewable energy sources and DC compatible loads in the grid has been increasing significantly. Furthermore, LVDC grids offer a higher efficiency and transmission capacity compared to their AC equivalent. However, the protection of these grids remains a major challenge for their breakthrough. This paper analyses the fault behaviour of an LVDC grid and proposes a prototype for a pole-to-ground protection device. To start with, an overview of the challenges for the protection against the different fault types in a converter-fed LVDC microgrid is presented. Subsequently, a PSCAD model of an LVDC grid for fault studies is discussed and the simulation results are analysed. Then, a test setup is developed to investigate the fault behaviour and the experimental results are presented and compared to the simulations. Finally, a prototype for pole-to-ground fault protection is proposed and its working principle is experimentally verified.

   Non-unit ROCOV scheme for protection of multi-terminal HVDC systems
By María José PÉREZ MOLINA [View]
[Download]

Abstract: Nowadays, high voltage direct current transmission systems are being selected over the traditionalalternating current transmission for very long transmission distances. However, there are still someunresolved challenges, most of them in terms of protection of the system. If using traditionalprotection systems used in alternating current grids, the characteristics of a DC fault make itcomplicated to clear and dangerous to power electronic components. Hence, there is a need of veryfast fault detection and clearance. This paper proposes a full-selective protection system based on arate of change of voltage. The process of selection of the threshold needed to discriminate faultconditions is described. In addition, the performance of the protection algorithm is analysed. Theinfluence of parameters such as the fault location and fault resistance is evaluated. A comparison withsimilar algorithms found on the literature is presented at the end.

   Protection Measures for Modular Multilevel Converters in Case of DC Short-Circuit Faults
By Martin GESKE [View]
[Download]

Abstract: The Modular Multilevel Converter (MMC) technology brings several advantages, although its operation and protection are very different compared to conventional Voltage Source Converters (VSC). Short circuit faults at the DC link transmission systems of MMCs that use the Half-Bridge Submodule (HB-SM) are still a major concern due to potentially high fault current magnitudes. The sequence of the pole-to-pole DC short circuit of an HB-MMC is analyzed and modeled through respective equivalent circuits. A simplified calculation is presented that allows estimating the current magnitudes after the DC-fault appearance. Finally, several protection measures for the HB-MMC are described, and a new protection method that uses an AC crowbar is introduced and analyzed.

EPE 2020 - DS3j-2: DC Grids, Hybrid DC Circuit breakers, Real-Time Simulation and Mock-ups
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2020 ECCE Europe - Conference > EPE 2020 - Topic 06: Grids, Smart Grids, AC & DC > EPE 2020 - DS3j-2: DC Grids, Hybrid DC Circuit breakers, Real-Time Simulation and Mock-ups
	[return to parent folder]

	Fault detection and classification based on deep learning in LVDC off-grid system By Iurii DEMIDOV	[View] [Download]
Abstract: The integration of information and communication technologies (ICT) into energy power systems provides new applications and possibilities for grid control, operation, and protection. In this paper, asmart self-sustained off-grid concept based on photovoltaics- and battery energy storage system andlow-voltage direct current (LVDC) power distribution network is studied. Due to small electrificationand poor internet coverage, Sub-Saharan Africa is the target area of the concept realization. Focusing on the application of deep learning, this research presents new approaches to the power system's protection, as fault detection and classification are one of the most essential LVDC electricity distribution issues.

	Feasibility Study of a Superconducting Power Filter for HVDC grids By Loic QUEVAL	[View] [Download]
Abstract: A new application of high temperature superconducting technology for HVDC grids is introduced. The device referred to as "superconducting power filter" (ScPF) aims at increasing the stability of HVDC grids by adding a current-dependent resistance to the grid. In comparison with other stabilization techniques, a ScPF achieves a fully passive stabilization with virtually no losses in nominal operation. To clarify its feasibility for HVDC grids, the HVDC grid test system DCS1 proposed by CIGRE B4 is considered. Using an electrical-thermal model of the device, the stability of the DC grid is numerically assessed depending on the design parameters of the device. The first steps towards an experimental proof of concept are presented.

	Modelling and Experimental Validation of a Pole-To-Ground Protection Device in Low Voltage DC Microgrids By Leonie HALLEMANS	[View] [Download]
Abstract: Over the past years, the scientific interest in Low Voltage DC grids as an alternative to traditional LVAC grids has been growing steadily. This is caused by the fact that the amount of renewable energy sources and DC compatible loads in the grid has been increasing significantly. Furthermore, LVDC grids offer a higher efficiency and transmission capacity compared to their AC equivalent. However, the protection of these grids remains a major challenge for their breakthrough. This paper analyses the fault behaviour of an LVDC grid and proposes a prototype for a pole-to-ground protection device. To start with, an overview of the challenges for the protection against the different fault types in a converter-fed LVDC microgrid is presented. Subsequently, a PSCAD model of an LVDC grid for fault studies is discussed and the simulation results are analysed. Then, a test setup is developed to investigate the fault behaviour and the experimental results are presented and compared to the simulations. Finally, a prototype for pole-to-ground fault protection is proposed and its working principle is experimentally verified.

	Non-unit ROCOV scheme for protection of multi-terminal HVDC systems By María José PÉREZ MOLINA	[View] [Download]
Abstract: Nowadays, high voltage direct current transmission systems are being selected over the traditionalalternating current transmission for very long transmission distances. However, there are still someunresolved challenges, most of them in terms of protection of the system. If using traditionalprotection systems used in alternating current grids, the characteristics of a DC fault make itcomplicated to clear and dangerous to power electronic components. Hence, there is a need of veryfast fault detection and clearance. This paper proposes a full-selective protection system based on arate of change of voltage. The process of selection of the threshold needed to discriminate faultconditions is described. In addition, the performance of the protection algorithm is analysed. Theinfluence of parameters such as the fault location and fault resistance is evaluated. A comparison withsimilar algorithms found on the literature is presented at the end.

	Protection Measures for Modular Multilevel Converters in Case of DC Short-Circuit Faults By Martin GESKE	[View] [Download]
Abstract: The Modular Multilevel Converter (MMC) technology brings several advantages, although its operation and protection are very different compared to conventional Voltage Source Converters (VSC). Short circuit faults at the DC link transmission systems of MMCs that use the Half-Bridge Submodule (HB-SM) are still a major concern due to potentially high fault current magnitudes. The sequence of the pole-to-pole DC short circuit of an HB-MMC is analyzed and modeled through respective equivalent circuits. A simplified calculation is presented that allows estimating the current magnitudes after the DC-fault appearance. Finally, several protection measures for the HB-MMC are described, and a new protection method that uses an AC crowbar is introduced and analyzed.