Aging Characteristics of Contact Electrodes of Low Voltage DC Switches

With the present state of the direct current (DC) distribution market, securing the safety of the DC distribution system is emerging as a major issue. Like AC distribution systems, DC switches and circuit breakers are one of the main means to ensure safety. However, in the DC system, since there is no current zero point in the load current, the phenomenon occurring when the circuit is cut off is different from that of the AC system, so technical research is required to cope with this. In this study, the aging characteristics of the contact electrode of a 400 V class low voltage DC (LVDC) switch is studied for the development of wall-mount switches or circuit breakers for residential houses. As an arc extinguishing method to break DC load current, a prototype experimental circuit breaker that uses a magnetic extinguishing method that is effective for blocking low voltage low power DC is invented, and an automated experiment system is established. The DC switch test repeats the operation of turning it on and off 13,000 times, and continuously evaluates the performance of the electric contacts by calculating the voltage drop between the electrode contacts and the corresponding Ohmic resistance value when conducting every 500 times. This paper tests six contact materials to compare the aging characteristics of them by evaluating contact resistance during the test period. AW18-Cu composite material showed the most stable and excellent contact performance for LVDC switches during the entire test operation period.

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Design and Testing of a Low Voltage Solid-State Circuit Breaker for a DC Distribution System

Energies ◽

10.3390/en13020338 ◽

2020 ◽

Vol 13 (2) ◽

pp. 338

Author(s):

Leslie Tracy ◽

Praveen Kumar Sekhar

Keyword(s):

Solid State ◽

Power Distribution ◽

Distribution System ◽

Distribution Systems ◽

Low Voltage ◽

Circuit Breaker ◽

Solid State Circuit ◽

Dc Distribution ◽

High Side ◽

Solid State Circuit Breaker

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.

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Voltage Regulation Method for Voltage Drop Compensation and Unbalance Reduction in Bipolar Low-Voltage DC Distribution System

IEEE Transactions on Power Delivery ◽

10.1109/tpwrd.2017.2694836 ◽

2018 ◽

Vol 33 (1) ◽

pp. 141-149 ◽

Cited By ~ 16

Author(s):

Tack-Hyun Jung ◽

Gi-Hyeon Gwon ◽

Chul-Hwan Kim ◽

Joon Han ◽

Yun-Sik Oh ◽

...

Keyword(s):

Distribution System ◽

Low Voltage ◽

Voltage Drop ◽

Voltage Regulation ◽

Dc Distribution ◽

Regulation Method

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Demonstration of Solid State Circuit Breakers within Low Voltage DC Distribution System for Shipboard Applications

2019 IEEE Electric Ship Technologies Symposium (ESTS) ◽

10.1109/ests.2019.8847821 ◽

2019 ◽

Cited By ~ 1

Author(s):

James Langston ◽

John Hauer ◽

Isaac Leonard ◽

Michael Sloderbeck ◽

Michael Steurer ◽

...

Keyword(s):

Solid State ◽

Distribution System ◽

Low Voltage ◽

Circuit Breakers ◽

Solid State Circuit ◽

Dc Distribution

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Experimental Study on Splitter Plate for Improving the Dielectric Recovery Strength of Low-Voltage Circuit Breaker

Electronics ◽

10.3390/electronics9122148 ◽

2020 ◽

Vol 9 (12) ◽

pp. 2148

Author(s):

Young-Maan Cho ◽

Kun-A Lee

Keyword(s):

Distribution System ◽

Heat Dissipation ◽

Electrode Materials ◽

Low Voltage ◽

Initial Period ◽

Circuit Breaker ◽

Splitter Plate ◽

Voltage Measurement ◽

Circuit Breakers ◽

Recovery Voltage

The low-voltage circuit breakers are widely used to protect loads in the distribution system. Interruption reliability of circuit breakers is important because they are a protective device close to the customer. In particular, the re-ignition phenomenon leads to over-current blocking failure due to the arc re-formed between electrodes despite the normal trip of the circuit breaker. In this paper, in order to improve the interruption performance against re-ignition, the dielectric recovery voltage measurement system of the circuit breaker is used and the experiment of changing the splitter plate is carried out. Two experiments are carried out by changing the splitter plate, especially changing the material of splitter plate and the number of lower plates of the splitter plate. In the case of changing the material of the splitter plate, the analysis is conducted according to the thermal conductance. In the case of changing the number of lower plates of the splitter plate, the number of plates and their spacing are variables. Analyzing the results of the dielectric recovery voltage experiment, in the initial period, copper plates have the best value that shows 102.1% improvement compared to normal and Al shows 59.8% improvement compared to normal. These increases are related to the thermal conductivity of the three electrode materials. In the case of changing the number of lower plates of the splitter plate, the 8-plates and 9-plates show 84.5% and 36.1% increases compared to normal, respectively, in the initial period. It can be seen that too many plates interfere with heat dissipation. Since this study studies performance improvement during the initial period, there is not much difference in the later period. This is consistent with the experimental results. In this study, an experimental basis is provided for the dielectric recovery strength from a low-voltage circuit breaker. It is expected that this will contribute to the research to improve the dielectric recovery capability of the circuit breaker.

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Criteria for the Design of Converters and Breakers in Low Voltage DC Distribution Systems

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.572.161 ◽

2013 ◽

Vol 572 ◽

pp. 161-164

Author(s):

Da Wei Meng ◽

Yu Feng Lu ◽

Yong Ming Xu ◽

Xi Feng Wang

Keyword(s):

Solar Cell ◽

Distribution System ◽

Distribution Systems ◽

Fossil Fuel ◽

Low Voltage ◽

Design Rules ◽

Dc Distribution ◽

The World ◽

Simulation Results ◽

Imported Oil

Recently, the shortage in fossil fuel causes the inflation around the world. Every nation is aware of the energy dependence on the imported oil and starts to invest on the replaceable energy such as fuel cell, solar cell and wind power. Besides of exploring more energy, cutting off the energy waste is another solution. However, for nearly all distribution system is AC-powered at present, the feasibility of DC distribution system should be discussed. Moreover, AC/DC converters and DC breakers which are two important components in DC distribution system are also the issues to be discussed. Therefore, in this thesis, the feasibility of DC distribution will be investigated. In addition, the feasible topologies and design rules of converter and breakers are proposed with the verification by simulation results.

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Practical Mitigation of Voltage Sag by Resonant Grounding in Distribution Systems: Case Study of Provincial Electricity Authority

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.433-440.3974 ◽

2012 ◽

Vol 433-440 ◽

pp. 3974-3979 ◽

Cited By ~ 2

Author(s):

Somchai Songsiri ◽

Sompon Sirisumrannukul

Keyword(s):

Distribution System ◽

Distribution Systems ◽

Fault Location ◽

Low Voltage ◽

Circuit Breaker ◽

Voltage Sag ◽

Distribution Transformer ◽

Useful Lifetime

This paper proposes a practical mitigation solution to the voltage sag problem by resonant grounding for a 22-kV distribution system of Provincial Electricity Authority (PEA). The simulation is carried out to investigate the voltage sag impact at the low voltage side of the delta/wye distribution transformer connected at the fault location in the existing solidly grounded system and proposed resonant grounded system by ATP-EMTP simulation. The results indicate that the proposed resonant grounding can help all customers connected at the same bus survive from voltage sag problems and also keep the customers on the faulty feeder connected to the system being continuously supplied. In addition, the distribution system with resonant ground lengthens the useful lifetime of the upstream circuit breaker of the feeder as its number of operations is significantly reduced.

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Formulated Representation for Upper Limitation of Deliverable Power in Low-Voltage DC Distribution System

IEEJ Transactions on Power and Energy ◽

10.1541/ieejpes.131.362 ◽

2011 ◽

Vol 131 (4) ◽

pp. 362-368 ◽

Cited By ~ 6

Author(s):

Yasunobu Yokomizu ◽

Doaa Mokhtar Yehia ◽

Daisuke Iioka ◽

Toshiro Matsumura

Keyword(s):

Distribution System ◽

Low Voltage ◽

Dc Distribution

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Soft-Switching Full-Bridge Converter with Multiple-Input Sources for DC Distribution Applications

Symmetry ◽

10.3390/sym13050775 ◽

2021 ◽

Vol 13 (5) ◽

pp. 775

Author(s):

Sheng-Yu Tseng ◽

Jun-Hao Fan

Keyword(s):

Conversion Efficiency ◽

Power Distribution ◽

Distribution System ◽

Distribution Systems ◽

Soft Switching ◽

Maximum Output ◽

Power Distribution Systems ◽

Distribution Method ◽

Dc Distribution ◽

Multiple Input

Due to the advantages of power supply systems using the DC distribution method, such as a conversion efficiency increase of about 5–10%, a cost reduction of about 15–20%, etc., AC power distribution systems will be replaced by DC power distribution systems in the future. This paper adopts different converters to generate DC distribution system: DC/DC converter with PV arrays, power factor correction with utility line and full-bridge converter with multiple input sources. With this approach, the proposed full-bridge converter with soft-switching features for generating a desired voltage level in order to transfer energy to the proposed DC distribution system. In addition, the proposed soft-switching full-bridge converter is used to generate the DC voltage and is applied to balance power between the PV arrays and the utility line. Due to soft-switching features, the proposed full-bridge converter can be operated with zero-voltage switching (ZVS) at the turn-on transition to increase conversion efficiency. Finally, a prototype of the proposed full-bridge converter under an input voltage of DC 48 V, an output voltage of 24 V, a maximum output current of 21 A and a maximum output power of 500 W was implemented to prove its feasibility. From experimental results, it can be found that its maximum conversion efficiency is 92% under 50% of full-load conditions. It was shown to be suitable for DC distribution applications.

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