scholarly journals Gate Drive Controller for Low Voltage DC Hybrid Circuit Breaker

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1753 ◽  
Author(s):  
Hyosung Kim

With the advent of direct current (DC) loads such as LED lighting, IT equipment, electric vehicles, and DC powers generated from renewable energy sources, low voltage DC (LVDC) distribution system is becoming a hot issue. One of the hurdles in the LVDC distribution system is arc flash at the contact points that occurs during the circuit is opening. Unlike alternating current, direct current has no zero points and sustains constantly. Therefore, there is a risk of electric fire due to continuous generating arcs when the load current is interrupted with an existing electrical contact type circuit breaker. Recently, the concept of a hybrid circuit breaker that takes advantage of traditional electrical contact type switch and the arcless semiconductor switch has been proposed, but how to cooperatively operate the two switches has become an issue. This paper analyzes the principle of a hybrid circuit breaker for blocking LVDC current and proposes a gate drive controller for it. Through 400V class LVDC cutoff test, the operation of the proposed hybrid circuit breaker is verified and the characteristics are analyzed.

2021 ◽  
Author(s):  
Sudipta Sen ◽  
Shahab Mehraeen ◽  
Keyue Smedley

Electronics ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 691 ◽  
Author(s):  
Ju-Yong Kim ◽  
Ho-Sung Kim ◽  
Ju-Won Baek ◽  
Dong-Keun Jeong

Low-voltage direct current (LVDC) distribution has attracted attention due to increased DC loads, the popularization of electric vehicles, energy storage systems (ESS), and renewable energy sources such as photovoltaic (PV). This paper studies a ±750 V bipolar DC distribution system and applies a 3-level neutral-point clamped (NPC) AC/DC converter for LVDC distribution. However, the 3-level NPC converter is fundamental in the neutral-point (NP) imbalance problem. This paper discusses the NP balance control method using zero-sequence voltage among various solutions to solve NP imbalance. However, since the zero-sequence voltage for NP balance control is limited, the NP voltage cannot be controlled to be balanced when extreme load differences occur. To maintain microgrid stability with bipolar LVDC distribution, it is necessary to control the NP voltage balance, even in an imbalance of extreme load. In addition, due to the bipolar LVDC distribution, the pole where a short-circuit condition occurs limits the short current until the circuit breaker operates, and a pole without a short-circuit condition must supply a stable voltage. Since the conventional 3-level NPC AC/DC converter alone cannot satisfy both functions, an additional DC/DC converter is proposed, analyzed, and verified. This paper is about a 3-level NPC AC/DC converter system for LVDC distribution. It can be used for the imbalance and short-circuit condition in bipolar LVDC distribution through the prototype of the 300 kW 3-level NPC AC/DC converter system and experimented and verified in various conditions.


Energies ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 338
Author(s):  
Leslie Tracy ◽  
Praveen Kumar Sekhar

In this study, a low voltage solid-state circuit breaker (SSCB) was implemented for a DC distribution system using commercially available components. The design process of the high-side static switch was enabled through a voltage bias. Detailed functional testing of the current sensor, high-side switch, thermal ratings, analog to digital conversion (ADC) techniques, and response times of the SSCB was evaluated. The designed SSCB was capable of low-end lighting protection applications and tested at 50 V. A 15 A continuous current rating was obtained, and the minimum response time of the SSCB was nearly 290 times faster than that of conventional AC protection methods. The SSCB was implemented to fill the gap where traditional AC protection schemes have failed. DC distribution systems are capable of extreme faults that can destroy sensitive power electronic equipment. However, continued research and development of the SSCB is helping to revolutionize the power industry and change the current power distribution methods to better utilize clean renewable energy systems.


Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3217
Author(s):  
Yun Geng ◽  
Xiaofei Yao ◽  
Jinlong Dong ◽  
Xue Liu ◽  
Yingsan Geng ◽  
...  

The prestrike phenomenon in vacuum circuit breakers (VCBs) is interesting but complicated. Previous studies mainly focus on the prestrike phenomenon in single-break VCBs. However, experimental work on prestrike characteristics of double-break VCBs cannot be found in literature. This paper aims to experimentally determine the probabilistic characteristics of prestrike gaps in a double-break VCB consisting of two commercial vacuum interrupters (VIs) in series under direct current (DC) voltages. As a benchmark, single-break prestrike gaps were measured by short-circuiting one of the VIs in a double break. The experimental results show that the 50% prestrike gap d50 of each VI in a double break, which is calculated with the complementary Weibull distribution, was significantly reduced by 25% to 72.7% compared with that in a single break. Due to the voltage-sharing effect in the double-break VCB, scatters in prestrike gaps of each VI in a double break was smaller than that in a single break. However, without the sharing-voltage effect, d50 of the low-voltage side in the double break was 65% higher than that of the same VI in the single break, which could be caused by the asynchronous property of mechanical actuators, the difference of the inherent prestrike characteristics of each VI and the unequal voltage-sharing ratio of VIs.


2018 ◽  
Vol 9 (3) ◽  
pp. 287 ◽  
Author(s):  
Kyle Smith ◽  
Dong Wang ◽  
Abdullah Emhemed ◽  
Stuart Galloway ◽  
Graeme Burt

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 322
Author(s):  
Hyeong-Jin Lee ◽  
Jin-Seok Kim ◽  
Jae-Chul Kim ◽  
Sang-Yun Yun ◽  
Sung-Min Cho

As the application of low-voltage-direct-current system increases, fault analysis in the low-voltage-direct-current system has essential because the fault response has different from the conventional AC distribution system. Especially, the fault current by the discharge current of the capacitor in the low-voltage-direct-current distribution system has very large compared with the conventional AC distribution system. Therefore, this paper proposed the application of the superconducting fault current limiter for limiting the fault current on the low-voltage-direct-current system. As one of the protected methods against fault current, the superconducting fault current limiter which could quickly limit the fault current has been noticed as an attractive method. However, the protection relay may malfunction such as over current relay, selective protection relay due to limiting fault current by applying superconducting fault current limiter. Therefore, in this paper proposed a solution to malfunction problem of the protection relay using the voltage components of the high temperature superconductivity. This paper verified the effect of the proposed method through test modelling and PSCAD/EMTDC.


Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2517
Author(s):  
Diogo Rupolo ◽  
Benvindo Pereira Junior ◽  
Javier Contreras ◽  
José Mantovani

In this paper, a multiobjective approach to carry out the planning of medium-voltage (MV) and low-voltage (LV) distribution systems, considering renewable energy sources (RES) and robustness, is proposed. Due to the uncertainties associated with RES and demand, the proposed planning methodology takes into account a robust planning index (RPI). This RPI allows us to evaluate the robustness estimation associated with each planning solution. The objective function in the mathematical model considers the costs of investment and operation and the robustness of the planning proposals. Due to the computational complexity of this problem, which is difficult to solve by means of classical optimization techniques, MV/LV planning is solved by a decomposition search and a general variable neighborhood search (GVNS) algorithm. To demonstrate the efficiency and robustness of this methodology, tests are performed in an integrated distribution system with 50 MV nodes and 410 LV nodes. Our numerical results show that the proposed methodology makes it possible to minimize costs and improve robustness levels in distribution system planning.


Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2388 ◽  
Author(s):  
Muhammad Ahmad ◽  
Zhixin Wang

The direct current circuit breakers are considered a promising option to protect the transmission line against commonly appearing line-to-ground fault. However, the challenges of losses in the nonoperational stage, escalation of response against fault current, and large fault current handling capability remain the debatable issues for direct current circuit breakers. This paper introduces a novel topology of the hybrid circuit breaker with fault-current-limiting characteristics, which contains three branches: the main branch, fault-current-limiting branch, and energy absorption branch. The main branch includes a mechanical switch, breaker impedance, and bidirectional power electronics switches. In the fault-current-limiting branch, a fault-current-limiting circuit is introduced which contains n numbers of bidirectional switches and current-limiting inductors, which are connected in series to make the design modular in nature. During the normal working stage, the current flows through the main branch of the breaker. Once a fault in the system is confirmed, the fault current is transferred to the fault-current-limiting branch. At this stage, the intensity of the fault current is reduced significantly using the fault-current-limiting circuit, and finally, the residual current is shifted to the energy absorption branch. The working principle, design considerations, and parametric analysis concerning the design of hybrid circuit breakers are incorporated in this paper. The performance of the proposed breaker is evaluated using a three-terminal voltage-source converter-based high-voltage direct current transmission network; for this purpose, a PSCAD/EMTDC simulation tool is used. The performance of the proposed breaker is also compared with other topologies. The comparative analysis shows that the proposed breaker is a good alternative considering high fault current interruption requirements, response time against fault current, and power losses.


Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5516
Author(s):  
Filip Relić ◽  
Predrag Marić ◽  
Hrvoje Glavaš ◽  
Ivica Petrović

In the modern power system, Flexible Alternating Current Transmission System (FACTS) devices are widely used. An increased share of the distributed generation (DG) and the development of microgrids change the power flows in the existing distribution networks as well as a conventional power flow direction from the transmission to the distribution network level which may affect the overall stability aspects. The paper shows the FACTS devices’ implementation influence on the performance of the distribution network with integrated renewable energy sources (RES) observing the aspects of the oscillatory stability and the low-voltage motor starting. The FACTS devices, in particular the static var compensators (SVC), have been allocated according to a novel algorithm proposed in the paper. The algorithm uses an iterative process to determine an optimal location for implementation and rating power of SVC considering active power losses minimization, improvement of the voltage profile and maximizing return of investment (ROI) of FACTS devices. Novel constraints—transformer station construction constraint, SVC industrial nominal power value constraint and the constraint of distribution system operator (DSO) economic willingness to investment in the distribution network development are considered in the proposed algorithm. The analysis has been performed on 20 kV rural distribution network model in DIgSILENT PowerFactory software.


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