Study on the spring modeling of circuit breaker with spring operating mechanism

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스프링조작기를 가진 고압회로차단기의 스프링 모델링에 관한 연구

이승규

․ 김승오

․ 유완석

․ 손정현

Study on the spring modeling of circuit breaker with spring operating mechanism

Seung-Kyu Lee, Seung-Oh Kim, Wan-Suk Yoo and Jeong-Hyun Sohn

Key Words: Circuit Breaker( 고압 회로차단기 ), Spring Operating Mechanism( 스프링 조작기 ),

탄성 다물체동역학 모드해석

Flexible Multibody Dynamics( ), Modal Analysis( )

Abstract

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.

Fig. 1 Spring operating system in circuit breaker

Paranjpe(1990)

(distributed

parameter) Sakai(1976)

Kim(1993) (lumped mass)

(equivalent stiffness) (lumped parameter) Ahn(2003)

(modal coordinates)

, 3 , ,

(linear model) (modal model) (nodal model)

2 3

4 5

2 스프링 시험 .

2.1 정적 시험

Fig.1 (UH-F100A)

Shimadzu 100

200mm 10mm/min Table 1

Fig. 2

Fig. 1 Material tester measuring spring characteristics

Table 1 Specifications of spring

Outer diameter 133.5mm

Inner diameter 102.5mm

Free length 629mm

Active number of turns 16

Fig. 2 Spring configuration

Fig. 3

28.17N/mm

Fig. 3 Static test result 2.2 동적 시험

Fig. 4,5 (actuator)

MTS 25ton

Fig. 5 A MTS machine for the horizontal dynamic test

100mm 100mm

3 Fig.6

Fig.6 "a"

"b"

(amplitude)

(a) 100mm (b) 100mm

Fig. 6 Specifications of sine excitation

Fig. 7 Spring forces according to time Fig.7

A,B C

3. 스프링 모델링

3.1 선형 모델

(1)

k x F

   (1)

3.2 모드 모델

MSC/Patran Fig. 8

Fig. 9

Table 2 Table 3

Table 3 x, y, z-axis Fig.2 (hexa element)

RecurDyn

MSC/Patran *.bdf

*.bdf MSC/Natran

*.pch

RecurDyn *.pch (importing)

37,316 223,914

Fig. 8 FEM model of spring

Table 2 Modeling data of spring Number of nodal points 37316

Number of elements 31042

Total degrees of freedom 223914 Young's modulus 2.1E+5 (N/mm2)

Poisson's ratio 0.3

Density 7.6E-6 (Kg/mm3)

Fig. 9 Mode shapes of spring

Table 3 Modeling data of spring Mode

no. Mode type f(Hz)

1 Symmetric(rotation about x-axis) 0.4552 2 Symmetric(rotation about z-axis) 0.4553

3 Axial 0.734

3.3 절점 모델 RecurDyn

RecurDyn MFBD

(jig)

(contact forces) Fig.8

RecurDyn

Patch set

4. 성능비교

4.1 정적 시험과 비교 RecurDyn

Fig.10

Table 4

. Table 4 RMS (root

mean square) , Max error .

Fig. 10 Comparison of static test results

Table 4 Comparison of errors of each model with Linear Modal Nodal

Accuracy

RMS

ratio(%) 1.1 1.6 1.4

Max

error(%) 1.8 1.6 2.4

Efficiency CPU

times(s) 5 621 11520

4.2 동적 시험과 비교

, .

Table 5

A, B C

Fig. 11 Comparison of horizontal dynamic test results

Table 5 Comparison of errors of each model with experiment

RMS error(N)

PEAK error (%)

A B C

Linear spring 31.32 2.2 22.1 0.6 Modal spring 42.43 3.6 23.9 0.8 Nodal spring 23.08 0.8 5.2 0.4

5. 결 론

. ,

, ,

, .

, ,

.

(1) , ,

(2)

후 기

2006 ( )

(KRF-2006-331-D00020)

참고문헌

(1) Paranjpe, R.S., 1990, "Dynamic Analysis of a Valve Spring With a Coulomb-Friction Damper", ASME J. of Mechanical Design, Vol. 115, pp.

412~422.

(2) Sakai, H. and Kosaki, H., 1976, "Analysis of Valve Motion in Overhead Valve Linkage-Roles of Valve Spring Surge in Valve Motion", J. of the Faculty of Eng. Uni. of Tokyo(B), Vol. XXXIII, No. 4, pp. 441~446.

(3) Kim, S.H., 1993, "Dynamic Analysis of a Helical Spring Using an Extended Finite Difference-type Numerical Scheme," Ph.D Thesis, KAIST, Taejon, Korea.

(4) Ahn, K.Y., Kim, S.H., 2003, "Influence of Spring Dynamics and Friction on Dynamic Responses in a Spring-Driven Cam," Transactions of the KSME (A), Vol.27, No.2, pp. 247~254.

(5) RecurDyn Theoretical Manual, 2006, Ver 6.0,

FunctionBay Co.