Undesirable repulsive force between contact members due to both a current path shrink near a real contact area and/or so-called pinch effect is particularly onerous for power switch applications, and results in either...Undesirable repulsive force between contact members due to both a current path shrink near a real contact area and/or so-called pinch effect is particularly onerous for power switch applications, and results in either contact floating or bouncing which are associated with an electric arc following contact welding. This problem is of great importance for any circuit breaker especially for compact low voltage vacuum circuit breakers. To avoid contact floating at closure and during any inrush current under short circuit conditions, the electrodynamic repulsive force can be employed successfully if we use a special compensation system flexibly combined with the contact itself. However to select and design the compensation system properly, its efficiency has to be known. This paper presents an approach to obtain the electrodynamic force value depending on different shaped (rectangular, square, circle and arch) copper plates used in the compensator by using ANSYS for current values 40 kA RMS. Curve-fitting was done according to the calculating results, the optimization designing of compensation unit is based on them.展开更多
Background A strong electromagnetic force is the major cause of vibration in dipole power supply cables.Moreover,the long-term operation of cables under vibration conditions leads to structural fatigue failure.Purpose...Background A strong electromagnetic force is the major cause of vibration in dipole power supply cables.Moreover,the long-term operation of cables under vibration conditions leads to structural fatigue failure.Purpose and methods To investigate the cable-laying scheme of a dipole power supply,a finite element model for the electromagnetic–structural coupling between cables and cleats was established.The electrodynamic forces were simulated for fixed-length cables in the horizontal,vertical,and bent models under pulse-current excitation.Subsequently,based on the optimized arrangement mode,the deformation of the cables and the stresses of the cleats were obtained.Results A small cable electrodynamic force was observed in the positive–negative interlace arrangement,and the cable deformation was caused by electrodynamic forces.The maximum cleat deformation occurred at the position with the largest electrodynamic force,where the cleats were reinforced.Moreover,the mechanical characteristics of the cables and cleats under pulse-current excitation are described intuitively and quantitatively,providing theoretical support for the cable-laying scheme of the dipole power supply.展开更多
文摘Undesirable repulsive force between contact members due to both a current path shrink near a real contact area and/or so-called pinch effect is particularly onerous for power switch applications, and results in either contact floating or bouncing which are associated with an electric arc following contact welding. This problem is of great importance for any circuit breaker especially for compact low voltage vacuum circuit breakers. To avoid contact floating at closure and during any inrush current under short circuit conditions, the electrodynamic repulsive force can be employed successfully if we use a special compensation system flexibly combined with the contact itself. However to select and design the compensation system properly, its efficiency has to be known. This paper presents an approach to obtain the electrodynamic force value depending on different shaped (rectangular, square, circle and arch) copper plates used in the compensator by using ANSYS for current values 40 kA RMS. Curve-fitting was done according to the calculating results, the optimization designing of compensation unit is based on them.
文摘Background A strong electromagnetic force is the major cause of vibration in dipole power supply cables.Moreover,the long-term operation of cables under vibration conditions leads to structural fatigue failure.Purpose and methods To investigate the cable-laying scheme of a dipole power supply,a finite element model for the electromagnetic–structural coupling between cables and cleats was established.The electrodynamic forces were simulated for fixed-length cables in the horizontal,vertical,and bent models under pulse-current excitation.Subsequently,based on the optimized arrangement mode,the deformation of the cables and the stresses of the cleats were obtained.Results A small cable electrodynamic force was observed in the positive–negative interlace arrangement,and the cable deformation was caused by electrodynamic forces.The maximum cleat deformation occurred at the position with the largest electrodynamic force,where the cleats were reinforced.Moreover,the mechanical characteristics of the cables and cleats under pulse-current excitation are described intuitively and quantitatively,providing theoretical support for the cable-laying scheme of the dipole power supply.
