In this paper, equivalent circuits for high frequency multi-winding magnetic components are derived from finite element (FE) computations. Lumped parameter models are first presented, based on previously published w...In this paper, equivalent circuits for high frequency multi-winding magnetic components are derived from finite element (FE) computations. Lumped parameter models are first presented, based on previously published work. All parameters of these circuits can be interpreted as the results of open and short-circuit tests on the transformer. Based on this consideration, numerical procedures are then proposed to derive frequency-dependent lumped parameters from FE simulations. By using an adequate formulation, parameters are directly obtained from the FE model degrees of freedom, without performing any volume integration in post-processing, which can be source of numerical errors. In this contribution, attention is paid on the modeling of magnetic coupling using inductances, and dissipative effects (winding and core losses) using resistances. The impact of conductor eddy currents on the circuit parameters is moreover studied in details. Instead of an analysis of the impact conductor eddy currents may have on the circuit parameters is moreover carried through.展开更多
While modeling a power supply system for an electric railway traction, knowing equivalent circuits of locomotives supplied this way is an essential issue. In alternating current traction, it is important to diagnose i...While modeling a power supply system for an electric railway traction, knowing equivalent circuits of locomotives supplied this way is an essential issue. In alternating current traction, it is important to diagnose inter alia processes taking place in transformers installed on electric vehicles. This article presents specific phenomena occurring during the work of mono-phase, multi-winding, multisystem (systems AC: 50 Hz, 16.7 Hz) laboratory traction transformer. It also shows difficulties encountered during the process of identifying multi-port equivalent scheme's elements of the described device, in which a construction defect occurs.展开更多
文摘In this paper, equivalent circuits for high frequency multi-winding magnetic components are derived from finite element (FE) computations. Lumped parameter models are first presented, based on previously published work. All parameters of these circuits can be interpreted as the results of open and short-circuit tests on the transformer. Based on this consideration, numerical procedures are then proposed to derive frequency-dependent lumped parameters from FE simulations. By using an adequate formulation, parameters are directly obtained from the FE model degrees of freedom, without performing any volume integration in post-processing, which can be source of numerical errors. In this contribution, attention is paid on the modeling of magnetic coupling using inductances, and dissipative effects (winding and core losses) using resistances. The impact of conductor eddy currents on the circuit parameters is moreover studied in details. Instead of an analysis of the impact conductor eddy currents may have on the circuit parameters is moreover carried through.
文摘While modeling a power supply system for an electric railway traction, knowing equivalent circuits of locomotives supplied this way is an essential issue. In alternating current traction, it is important to diagnose inter alia processes taking place in transformers installed on electric vehicles. This article presents specific phenomena occurring during the work of mono-phase, multi-winding, multisystem (systems AC: 50 Hz, 16.7 Hz) laboratory traction transformer. It also shows difficulties encountered during the process of identifying multi-port equivalent scheme's elements of the described device, in which a construction defect occurs.