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ABSTRACT: Linkage transfer phenomenon, which exists in the opening process of the operating mechanism of the molded case circuit breaker MCCB, is introduced. The influence of the linkage transfer position on the behavior of the mechanism is analyzed. According to the analysis result, the linkage transfer position of an actual operating mechanism is improved with virtual prototype technology software ADAMS. Simulation and experiment results show that after improvement, the opening time of the mechanism is shortened by about 1 ms. Short-circuit tests demonstrate that the operating mechanism with its linkage transfer position improved is helpful for enhancing the interruption performance of MCCB while breaking the low-current faults.
IEEE Transactions on Power Delivery 02/2011; · 1.35 Impact Factor
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IEICE Transactions. 01/2011; 94-C:1416-1421.
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ABSTRACT: A 2-D magnetohydrodynamic (MHD) arc model is developed to simulate the influence of the venting configuration on air arc plasma motion in a low-voltage circuit breaker. It is demonstrated that the fully closed back venting is helpful to accelerate the arc motion due to the propagation of a pressure wave. Side- and central-type front-venting configurations are also compared. It is found that the arc velocity is higher, and yet the probability of reignition is increased for the central-type front venting, as a consequence of differences in the current density distribution. Using an arc chamber with different venting configurations, short-circuit interruption experiments are carried out. These verify the arc reignition trends predicted in the simulations.
IEEE Transactions on Plasma Science 10/2010; · 1.17 Impact Factor
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ABSTRACT: Research on the interruption process of control and protective switch devices (CPS) is helpful for improving its current-limiting performance. Three different structures of the main contact system are proposed and experimentally investigated on their influence on CPS's interruption performance first. Then, a calculation model that enables us to simulate the interruption process of a low-voltage apparatus with a complex mechanical structure is realized by carrying out the second development of ADAMS, in which a set of differential equations describing the coupling of complex mechanical movements, electric circuits, magnetic fields, and dynamic mathematic arc models is constructed. With this model, further investigations on the interruption process, arc movement, and arc characteristic variation of CPS with the three main contact systems are carried out. The improvement mechanism of the current-limiting performance of CPS using an arc run-on plate is especially analyzed with the calculation model.
IEEE Transactions on Power Delivery 08/2010; · 1.35 Impact Factor
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IEICE Transactions. 01/2010; 93-C:1404-1410.
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IEICE Transactions. 01/2010; 93-C:1399-1403.
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IEICE Transactions. 01/2010; 93-C:1424-1430.
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ABSTRACT: This paper is devoted to study the influence of ferromagnetic material on arc behavior in low voltage electric apparatus. With the self-programmed interface, one 2-D magnetohydrodynamic arc model can be developed based on the commercial software FLUENT and ANSYS, to study the vapor of ferromagnetic material effects on air arc behavior. Then, the corresponding interruption experiments are performed to verify the simulation qualitatively. It demonstrates that the vapor of ferromagnetic material is disadvantageous to arc interruption characteristics. In addition, the influence of the size of the ferromagnetic splitter plate on arc motion is simulated. It shows that the bigger splitter plate may accelerate the arc motion.
IEEE Transactions on Plasma Science 04/2009; · 1.17 Impact Factor
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IEICE Transactions. 01/2009; 92-C:1052-1057.
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IEICE Transactions. 01/2009; 92-C:1040-1044.
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ABSTRACT: A two-dimensional arc magnetohydrodynamic model is presented to study the effects of metallic vapour and gassing material on air switching arc motion based on different mixture plasma properties (pure air, 99% air–1% Cu, 99% air–1% Ag, 99% air–1% Fe, 90% air–10% PA6). It demonstrates that metallic vapours may cool the arc central region and reduce the arc motion velocity, and iron vapours have the strongest action compared with copper and silver vapours; the gassing material may improve the arc motion velocity. In addition, the effect of the net emission coefficient model and the grey body radiation model on the calculation results for pure air arc motion is compared. To verify the simulation results partially, using the integrated imaging diagnostics system, experiments are carried out to measure the average velocity of arc motion with one model chamber.
Journal of Physics D Applied Physics 11/2007; 40(22):6982. · 2.54 Impact Factor
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ABSTRACT: The arc is one kind of mixture plasma containing air and metallic vapour (Cu, Ag, Fe, etc.) in low voltage circuit breaker. The metallic vapour has important influence on arc characteristics because the properties of the mixture plasma are different with the ones of the pure air. The influence of Cu vapour on air arc characteristics is investigated in the paper. Firstly, commercial computational fluid dynamics software FLUENT is adapted and modified to develop the two- dimensional magneto-hydrodynamic (MHD) models of arc with the thermodynamic and transport properties, net emission coefficient for radiation model of 99% Air-1% Cu and pure air, respectively. Then, relevant experiments are carried out to verify the models by measuring the arc motion average velocities with 2-D optical fiber measurement system. It demonstrates that with the influence of Cu vapour, the arc center temperature is lower and the arc motion is slower.
Electrical contacts - 2007, the 53rd ieee holm conference on; 10/2007
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ABSTRACT: In the optimization design of contact system for the air circuit breaker (ACB), it is important to calculate the short-time withstand current. Introducing the contact bridges to describe contact spots between movable and fixed contacts, transient analysis is carried out by coupling electromagnetic field and thermal field to parallel contact systems, where nonlinear of ferromagnetic splitter plates and properties of conduct material varying with temperature are under consideration. In each time step of calculation, the cross-sectional areas of the contact bridges are changed with the contact forces by Holm formula. The proposed method could be used to analyze the short-time withstand current of ACB.
Electrical contacts - 2007, the 53rd ieee holm conference on; 10/2007
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ABSTRACT: In the optimum design of AC contactors, it is important to analyze the dynamic behavior. Moreover, movable contact and core bounces have remarkable effect on the lifetime of contactors. According to a kind of intelligent contactor with feedback mechanism, this paper builds two different sets of periodically inter-transferred equations. The equations describe the coupling of the electric circuit, electromagnetic field and mechanical system taking account of the influence of friction. And with virtual prototyping technology, the dynamic behavior of the contactor can be obtained. The paper introduces the contact resistance to investigate the bounce of the contact.
Electrical contacts - 2007, the 53rd ieee holm conference on; 10/2007
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ABSTRACT: Pressure rise of the gas due to high current arc in the arc chamber of molded case circuit breaker (MCCB) may accelerate the arc movement and improve the corresponding interruption performance. However, this pressure rise may result in a heavy stress on the enclosure of the arc chamber. The paper is devoted to calculate the pressure rise and analyze its characteristics. Based on thermodynamics and ideal gas law, the pressure rise variation with time could be calculated taking into account the influence of arc current, venting size, splitter plates and gassing material. Relevant experiments also were carried out to verify the proposed calculation method. It demonstrates that the pressure rise in the arc chamber will be increased with the higher arc current, less venting and the existence of gassing material.
Electrical contacts - 2007, the 53rd ieee holm conference on; 10/2007
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ABSTRACT: A dynamic model of the operating mechanism for a low voltage molded case circuit breaker (MCCB) was built based on virtual prototype technology, and then a test was done to verify this model, which showed that simulation results of virtual model were in agreement with test results of real prototype. After adding electric repulsion force to model, the operating time of mechanism was shortened about 2 ms. Using this model, besides the repulsion force, the factors including the stiffness of opening spring, the shape of mechanism parts affected the dynamic characteristics of operating mechanism are analyzed as well, and it also indicates that centroidy coordinates of trip has the greatest influence on angular velocity of operating mechanism. Selecting x and y coordinates of mechanism axes as the design variables, after optimum design, average angular velocity of operating mechanism has risen 15.3%.
Electrical contacts - 2007, the 53rd ieee holm conference on; 10/2007
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ABSTRACT: To the optimization design of molded case circuit breakers (MCCBs), it is important and necessary to simulate the interruption process and analyze the characteristics. A set of differential equations can describe the interactive coupled phenomena of electric circuit, electromagnetic field and mechanism motion system in MCCB. First, with virtual prototyping technology, the simulation model for the operation mechanism of MCCB can be built, and experiments have been carried out to verify its validity. Then, with the existence of electrodynamic repulsion force, the interruption process of the MCCB has been investigated with the influence of arc voltage, closing phase angle, prospective current, mechanism starting motion time and blow open force. It demonstrates the proposed method is effective and is capable of evaluating the new design of MCCB products.
IEEE Transactions on Components and Packaging Technologies 10/2007; · 0.94 Impact Factor
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IEICE Transactions. 01/2007; 90-C:1466-1471.
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IEICE Transactions. 01/2007; 90-C:1460-1465.
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IEICE Transactions. 01/2006; 89-C:1201-1205.
