Interlink hybrid DC circuit breaker

—To protect HVDC grids from DC faults, the concept of a hybrid DC circuit breaker is widely accepted due to its low conduction losses and fast interruption speed. For a well-built DC grid, a massive number of hybrid DC circuit breakers have to be installed. This will lead to high capital costs. An interlink DC circuit breaker based on an idea of sharing main breaker branch between two circuit breakers is proposed to reduce the overall costs of circuit breakers in a DC grid. Comparing with existing hybrid DC circuit breakers, the interlink hybrid DC circuit breaker can achieve the same DC fault interruption capability with fewer components. Novel structures of main breaker branches are designed and their parameters are determined to make the interlink hybrid DC circuit breakers be capable for both unidirectional and bidirectional interruption on demand. For a unidirectional interlink hybrid DC circuit breaker, the size of MOVs is reduced by 50%. For a bidirectional interlink hybrid HVDC circuit breaker, the number of IGBTs and MOVs are reduced by 25%. The interlink hybrid DC breakers are verified and compared to the hybrid DC circuit breaker via a three-terminal HVDC grid in PSCAD/EMTDC

Series LC DC Circuit Breaker

This work was supported by the Europend Udiod’s Horizon 2020 research and innovation program under grant No. 691714. The author is thankful to Mr R. Osborne from University of Aberdeen for help with the experimental studiesPeer reviewedPublisher PD

Arcless opening of direct current circuits in technical systems

Operation of the proposed DC circuit breaker consists in the fact that the closing of the thyristor in the DC power circuit with an inductive load results from opening the auxiliary circuit with a current value several fold less than the load current. The power and auxiliary circuits are connected by means of a current transformer having counter switch windings. After switching, the load is shunted by a diode and does not affect the transition process. Simulations and experimental tests of the DC circuit breaker model showed its performance capability, and the breaker can be used for switching in existing DC high current circuits with inductive loads

Model of interrupter DC circuit breaker

Import 26/06/2013Práce se zaměřuje na modelování elektrického oblouku uvnitř zhášecí komory stejnosměrného rychlo vypínače. Na realizaci virtuálního modelu konkrétního typu zhášecí komory stejnosměrného rychlo vypínače bylo využito vývojové prostředí SolidWorks . V mém případě byl vybrán typ zhášecí komory 1X2 z typové řady stejnosměrných vypínačů N-RAPID vyráběné závodem Postřelmov. V toto modelu jsou nasimulovány pozice oblouku v dané posloupnosti. Poté byl model převeden do výpočetního prostředí Workbench od společnosti ANSYS jenž se specializuje na výpočty Metodou konečných prvků. Posléze byly modelu přiřazeny dané atributy a proveden výpočet jenž zahrnuje rozložení silových poměrů, rozložení magnetické indukce, intenzity magnetického pole a proudové hustoty v celém modelu.This thesis is focused on modeling the electric arc inside the arc chute of the DC High-Speed Circuit Breaker. For the implementation of a virtual model of a particular type of the DC High-Speed Circuit arc chute was used development environment SolidWorks. In my case, I selected the 1X2 type of DC High-Speed Circuit Breaker N-RAPID manufactured by manufacturer Postrelmov. In this model was simulated position of the arc in the given sequence. The model was then transferred to the model computing environment from ANSYS Workbench which specializes in finite element analysis. Given attributes were later assigned to the model and performed a calculation which included the distribution of power ratios, the distribution of magnetic flux density, magnetic field and current density throughout the model.410 - Katedra elektroenergetikyvýborn

Successful fault current interruption on DC circuit breaker

This study focus on the interruption capability of the DC circuit breaker employing a current commutation approach and evaluates the two main factors that determine the success rate for breaker current interruption, namely the current slope di/dt before current zero and the rate of rise of the transient recovery voltage dv/dt across the mechanical breaker contacts after current zero. A vacuum circuit breaker is used to evaluate DC breaker characteristics. Detailed mathematical and graphical analysis are presented for the proposed circuit operation used in analysing the circuit breaker properties, with simulation and experimental results at fault current levels up to 330 A

LC DC Circuit Breaker based on Precharged Capacitor Commutation

Acknowledgment This project is funded by SFC COVID 19 grant. The author is thankful to Mr Richard Osborne, technician from University of Aberdeen for the experimental studies.Peer reviewedPostprin

Reduced DC circuit breaker requirement on mixed converter HVDC networks

© 2015 IEEE.Recently proposed meshed HVDC networks include both converters and DC circuit breakers, and the fault currents experienced and therefore the capacity requirement of circuit breakers are dependent on the topology of converters used on the network. This paper analyses the difference in fault currents seen in various network configurations utilising fault-feeding and fault-blocking converters. Results are presented showing the reduced fault currents seen in the regions of the DC network where fault current limiting converters have been implemented, which could have an impact on the topology, current rating and therefore size and cost of the circuit breaker