EPE Association: EPE 2015 - LS6f: Protection in DC and AC Grids

EPE 2015 - LS6f: Protection in DC and AC Grids
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2015 ECCE Europe - Conference > EPE 2015 - Topic 06: Grids and Smart Grids > EPE 2015 - LS6f: Protection in DC and AC Grids

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   A DC grid primary protection algorithm based on current measurements
By Sahar PIROOZ AZAD [View]
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Abstract: This paper proposes a data-based primary fault detection and identification (FDI) algorithm for HVDCgrids. The proposed FDI algorithm utilizes only current measurements to identify the protection zoneof the DC grid where the DC fault occurs. In contrast to the previously studied data-based methods inliterature, the proposed algorithm of this paper uses features obtained from current rather than voltagemeasurements. The FDI algorithms which are based on voltage measurements also require the measurements obtained from current sensors to distinguish between faults on DC transmission lines and busterminals. This paper also presents a detailed model of an optical current transducer (OCT) and investigates how the accuracy and speed of the proposed FDI algorithm is impacted by i) measurement noiseand ii) sampling frequency.The proposed algorithm is applied to a four-terminal HVDC grid. The current measurements provided tothe relays are obtained from elaborately modeled OCTs. Study results show that the proposed algorithmaccurately detects faults at DC transmission lines and converter bus terminals and identifies the protectionzone where the fault occurs (bus terminal or transmission line). The performance of the FDI algorithmdoes not degrade in case of various measurement noises, i.e., optical, electronics unit, and quantization.Furthermore, the range of sampling frequency for which the proposed algorithm can be used withoutlosing accuracy is investigated.

   A New Topology of Fast Solid-state HVDC Circuit Breaker for Offshore Wind Integration Applications
By ATAOLLAH MOKHBERDORAN [View]
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Abstract: Emerging new voltage source converter based HVDC applications demand fast short-circuit fault current interruption. Fast dc circuit breakers are identified as the feasible solution to handle the dc fault current. Switching overvoltage across the dc circuit breakers is destructive for the interrupter device and also for the other components of the system. A new topology of fast solid-state circuit breaker for HVDC applications is proposed in this paper. Instead of conventional approaches, a pre-charged capacitor is used for soft switching. Different modes of operation of proposed circuit breaker are analysed and also design process of circuit parameters are described. Finally, simulation results are presented.

   Design of a Centralized Protection Technique for Medium Voltage DC Microgrids
By Mehdi MONADI [View]
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Abstract: This paper presents a communication-assisted protection technique for dc microgrids. The technique, consist of a centralized fault detection, by use of the differential method; and a fault isolation strategy by coordinated operation of dc breakers and isolator switches. Hardware in the loop simulation is used to evaluate the proposed protection.

   Development and test of a 200kV full-bridge based hybrid HVDC breaker
By ZHOU WAN DI [View]
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Abstract: Recent development in DC technologies and renewable energy increase the requirement in building large HVDC networks. The world first Zhoushan five-terminal HVDC project constructed in China has been put into operation. To increase the operation reliability, a HVDC circuit breaker will be required. However the existing HVDC breaker developed in recent years still can't deal with severe fault current of a high rise of rate in this project. Considering the availability in a real HVDC network, this paper proposed a new full-bridge based hybrid HVDC breaker.The hybrid HVDC breaker has significant technical advantage compared with other options especially in terms of current breaking ability, and the compact modular integration of the prototype greatly reduce the demand of the space. Safely test procedures is developed to verify the performance of the hybrid HVDC breaker. The test results show that the full-bridge hybrid HVDC breaker could be used in the Zhoushan five-terminal project.

EPE 2015 - LS6f: Protection in DC and AC Grids
You are here: EPE Documents > 01 - EPE & EPE ECCE Conference Proceedings > EPE 2015 ECCE Europe - Conference > EPE 2015 - Topic 06: Grids and Smart Grids > EPE 2015 - LS6f: Protection in DC and AC Grids
	[return to parent folder]

	A DC grid primary protection algorithm based on current measurements By Sahar PIROOZ AZAD	[View] [Download]
Abstract: This paper proposes a data-based primary fault detection and identification (FDI) algorithm for HVDCgrids. The proposed FDI algorithm utilizes only current measurements to identify the protection zoneof the DC grid where the DC fault occurs. In contrast to the previously studied data-based methods inliterature, the proposed algorithm of this paper uses features obtained from current rather than voltagemeasurements. The FDI algorithms which are based on voltage measurements also require the measurements obtained from current sensors to distinguish between faults on DC transmission lines and busterminals. This paper also presents a detailed model of an optical current transducer (OCT) and investigates how the accuracy and speed of the proposed FDI algorithm is impacted by i) measurement noiseand ii) sampling frequency.The proposed algorithm is applied to a four-terminal HVDC grid. The current measurements provided tothe relays are obtained from elaborately modeled OCTs. Study results show that the proposed algorithmaccurately detects faults at DC transmission lines and converter bus terminals and identifies the protectionzone where the fault occurs (bus terminal or transmission line). The performance of the FDI algorithmdoes not degrade in case of various measurement noises, i.e., optical, electronics unit, and quantization.Furthermore, the range of sampling frequency for which the proposed algorithm can be used withoutlosing accuracy is investigated.

	A New Topology of Fast Solid-state HVDC Circuit Breaker for Offshore Wind Integration Applications By ATAOLLAH MOKHBERDORAN	[View] [Download]
Abstract: Emerging new voltage source converter based HVDC applications demand fast short-circuit fault current interruption. Fast dc circuit breakers are identified as the feasible solution to handle the dc fault current. Switching overvoltage across the dc circuit breakers is destructive for the interrupter device and also for the other components of the system. A new topology of fast solid-state circuit breaker for HVDC applications is proposed in this paper. Instead of conventional approaches, a pre-charged capacitor is used for soft switching. Different modes of operation of proposed circuit breaker are analysed and also design process of circuit parameters are described. Finally, simulation results are presented.

	Design of a Centralized Protection Technique for Medium Voltage DC Microgrids By Mehdi MONADI	[View] [Download]
Abstract: This paper presents a communication-assisted protection technique for dc microgrids. The technique, consist of a centralized fault detection, by use of the differential method; and a fault isolation strategy by coordinated operation of dc breakers and isolator switches. Hardware in the loop simulation is used to evaluate the proposed protection.

	Development and test of a 200kV full-bridge based hybrid HVDC breaker By ZHOU WAN DI	[View] [Download]
Abstract: Recent development in DC technologies and renewable energy increase the requirement in building large HVDC networks. The world first Zhoushan five-terminal HVDC project constructed in China has been put into operation. To increase the operation reliability, a HVDC circuit breaker will be required. However the existing HVDC breaker developed in recent years still can't deal with severe fault current of a high rise of rate in this project. Considering the availability in a real HVDC network, this paper proposed a new full-bridge based hybrid HVDC breaker.The hybrid HVDC breaker has significant technical advantage compared with other options especially in terms of current breaking ability, and the compact modular integration of the prototype greatly reduce the demand of the space. Safely test procedures is developed to verify the performance of the hybrid HVDC breaker. The test results show that the full-bridge hybrid HVDC breaker could be used in the Zhoushan five-terminal project.