VP11-09 Space-Time Simulation of Fault Current Limiters Involving Cores Exhibiting Hysteresis
Creators: Amr Adly
Publisher: name: IEEE
Year: 2025

Power systems are becoming more complex due to the recent trends of integration of different non-traditional sources as well as monitoring and protection components. While circuit breakers represent the main power systems protection components, inclusion of fault current limiters in specific network zones can enhance the protection level in addition to downscaling specifications requirements of those circuit breakers. In recent years, considerable efforts have been directed towards the development of fault current limiters. In these efforts, limiters comprised of conventional conducting coils have emerged as practical and low-cost alternatives (see [1]-[3]). For most fault current limiters laminated cores are utilized. However, the operation mechanism of such limiters offers the possibility of employing low-cost solid cores. In such cases, their design methodologies become more complicated since pronounced hysteresis and eddy currents and their effects on the limiters transient current limitation performance would have to be taken into consideration. The purpose of this paper is to present a space-time finite difference simulation approach for fault current limiters involving solid conducting cores exhibiting hysteresis as shown in Fig. 1. According to this approach, Maxwell’s equations for each of the cylindrical cores may be expressed as [4]: ▽X▽XH=-σ(∂B/∂H)(∂H/∂t) (1) H_core1=H_DC+H_AC (2) H_core2=H_DC-H_AC (3) where, σ is the core conductivity, B is the flux density and H is the field resulting from the superposition of the applied bias DC current and the AC load current. An important feature of this approach is its ability to highlight the limiter surge current limitation as a function of its conductivity and complex magnetic properties thus facilitating its accurate design actions. Sample correlation between the limiter flux of its dual cores and the load current before and after a short circuit fault instant is shown in Fig. 2. Details of the approach, its computational approach and more simulation results are presented in the full paper.References: [1] J.W. Moscrop, IEEE Transactions on Magnetics, Vol. 49, pp. 874-882 (2013). [2] J. Yuan et. al., Jiaxin, High Voltage, Vol. 5, pp. 416-424 (2020). [3] J.C. Knott and J.W. Moscrop. IEEE Transactions on Magnetics, Vol. 49, pp. 4132-4136 (2013). [4] A.A. Adly, Journal of Applied Physics, Vol. 79, pp. 4675-4677 (1996).
Power systems are becoming more complex due to the recent trends of integration of different non-traditional sources as well as monitoring and protection components. While circuit breakers represent the main power systems protection components, inclusion of fault current limiters in specific network zones can enhance the protection level in addition to downscaling specifications requirements of those circuit breakers. In recent years, considerable efforts have been directed towards the development of fault current limiters. In these efforts, limiters comprised of conventional conducting coils have emerged as practical and low-cost alternatives (see [1]-[3]). For most fault current limiters laminated cores are utilized. However, the operation mechanism of such limiters offers the possibility of employing low-cost solid cores. In such cases, their design methodologies become more complicated since pronounced hysteresis and eddy currents and their effects on the limiters transient current limitation performance would have to be taken into consideration. The purpose of this paper is to present a space-time finite difference simulation approach for fault current limiters involving solid conducting cores exhibiting hysteresis as shown in Fig. 1. According to this approach, Maxwell’s equations for each of the cylindrical cores may be expressed as [4]: ▽X▽XH=-σ(∂B/∂H)(∂H/∂t) (1) H_core1=H_DC+H_AC (2) H_core2=H_DC-H_AC (3) where, σ is the core conductivity, B is the flux density and H is the field resulting from the superposition of the applied bias DC current and the AC load current. An important feature of this approach is its ability to highlight the limiter surge current limitation as a function of its conductivity and complex magnetic properties thus facilitating its accurate design actions. Sample correlation between the limiter flux of its dual cores and the load current before and after a short circuit fault instant is shown in Fig. 2. Details of the approach, its computational approach and more simulation results are presented in the full paper.References: [1] J.W. Moscrop, IEEE Transactions on Magnetics, Vol. 49, pp. 874-882 (2013). [2] J. Yuan et. al., Jiaxin, High Voltage, Vol. 5, pp. 416-424 (2020). [3] J.C. Knott and J.W. Moscrop. IEEE Transactions on Magnetics, Vol. 49, pp. 4132-4136 (2013). [4] A.A. Adly, Journal of Applied Physics, Vol. 79, pp. 4675-4677 (1996).