• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.365-366
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• 2006

Hydraulic circuit breaker is the most popular type of electric power circuit breaker because of its superiority of operating performance and capacity. For the improvement of hydraulic circuit breaker's operating performance, it is very important to analyze its dynamic behavior characteristics. In this study, hydraulic circuit is modeled, analyzed and experimented. As a result, the experimental data agree well with the numerical ones, and the numerical results can be applied to the design and the improvement of hydraulic electric power circuit breaker.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.433-436
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• 2007

This paper analyzes how to calculate the three phase short-circuit currents for ac electrical system and select the high & low voltage circuit breaker based on IEC60609, IEC60056 and IEC60947-2 standards. We proposed the multiplying factor considering system time constant and circuit breaker rating to select circuit breaker accurately.

• Journal of the Korean Society of Safety
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• v.29 no.4
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• pp.54-60
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• 2014

This paper describes electric shock accidents on a 4.16 kV class circuit breaker for power plant. Electric shock accidents mostly involve damage of human life, in comparison with electrical fire, rate of human death tend to be higher in electric shock accidents. Specially, in a high voltage facilities rate of human death comprised about 43.7% by electric shock accidents. If electric shock accidents happen in a 4.16 kV class circuit breaker for power plant, then the power plant discontinue power production. Electric shock accidents in a power plant have a great ripple effect such as an electric power shortage. In this paper, we analyzed electric shock accidents on a 4.16 kV class circuit breaker for power plant. From the analysis results, we confirmed a cause of electric shock accidents on a 4.16 kV class circuit breaker, it happened by defect of interlock equipment or occurrence of breakdown between first feeder contactor and shielding plate. In order to reduce electric shock accidents on a 4.16 kV class circuit breaker, the power plant should consider improvement of interlock equipment and insulation of feeder contactor in circuit breaker.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.991-996
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• 2007

Since the performance of the circuit breaker mainly depends on the spring operating mechanism, the analysis of the spring operating mechanism is required. The spring, especially closing spring, stores the deformation energy due to the compression and then accelerates the big loads rapidly in the circuit breaker. To accurately carry out the kinematic and dynamic analysis of the circuit breaker, the precise modeling of the spring behavior is necessary. In this paper, the static stiffness of the spring is captured by using the tester. When the spring is used in the circuit breaker, it is installed horizontally. Therefore, Sine excitation tests are carried out horizontal and vertical direction. Three types of spring models such as a linear spring model, modal spring model, and nodal spring model are suggested and compared with the experimental results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1418-1421
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• 2003

The Vacuum circuit breaker is a kind of power circuit breaker and protect electric devices from over-current. In this paper we built a dynamic model of VCB driving mechanism using ADAMS. The development of the new circuit breaker with less energy and more compactable mechanism is focused. Through the dynamic model, the concept design of the new circuit breaker with less energy and more compactable mechanism is proposed, and then the detailed design is carried out through the design process based on the dynamic model.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.4
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• pp.43-49
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• 2004

A spring-actuated linkage system is used to satisfy the desired opening and closing characteristics of the electric contacts of a vacuum circuit breaker. If the type of a circuit breaker and the structure of the linkage system are predetermined, then design parameters such as stiffness, free length and attachment points of the spring become the important issues. In this paper, based on the energy conservation, the total system energy is constant throughout the operating range of the mechanism; a systematic procedure to optimize the spring design parameters is developed and applied to a simplified mechanism of a circuit breaker. The developed procedure is converted to the environment of the multi-body dynamics program, ADAMS for an in-depth consideration of the complex dynamics of a circuit breaker mechanism.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.8
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• pp.396-402
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• 2006

Even the case DC circuit Breaker have good quality for interruption of high current like heavy load current, short-circuit current, the verification for small current breaking capability of circuit breaker should be performed. It comes from the reason DC small current breaking failure can be lead to break out second heavy fault condition and in the long run substation shutdown. In this paper, we can find the characteristics of DC small current and international test standard discription about small current breaking and one of the proper solution to get over it.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.4
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• pp.369-374
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• 2015

The circuit breaker in an electric power system is not operated when the voltage in the circuit breaker is higher than the rated transient recovery voltage (TRV). The TRV of a circuit breaker is characterized by re-ignition of the arc between two poles and determined by the value of connecting impedance. In this study, we simulated the peak value of TRV in the AC filter of the circuit breaker. The suitability of TRV is assessed by capacitive current switching test conditions defined by the international guide IEC62271-100.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.476-481
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• 2001

In this paper, based on the developed dynamic model of a vacuum circuit breaker mechanism, the development of the new circuit breaker with less energy mechanism is focused. The energy flow analysis of the original mechanism is carried out to show where the elastic potential energies of pre-loaded springs are transmitted. Through energy flow analysis, the concept design of the new circuit breaker with less energy mechanism is proposed, and then the detailed design is carried out through the design process based on the verified dynamic model. Comparing simulation results with experiment using a high-speed camera, the appropriateness of the proposed design procedures for the rapid circuit breaker mechanism is shown.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.8
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• pp.132-139
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• 2011

Technical requirements for medium voltage class circuit breaker were harmonized by IEC and IEEE, and IEC newly adopted the requirements for class S2 circuit-breaker for overhead-line with the ratings of high-frequency TRV(Transient Recovery Voltage), which IEEE already adopted. Under these circumstances, KERI(Korea Electrotechnology Research Institute) studied testing technologies and facilities, which enable to perform interrupting capacity tests for class S2 circuit-breaker. As results, KERI could carry out interrupting capacity tests for medium voltage class circuit breaker rated up to 3-phase 52[kV] 40[kA], which satisfies the IEC standard.