This paper proposes an improved modularizable high-frequency battery equalizer with multi-winding transformer for energy storage systems. The involvement of parasitic components in circuit resonance, along with the ad...This paper proposes an improved modularizable high-frequency battery equalizer with multi-winding transformer for energy storage systems. The involvement of parasitic components in circuit resonance, along with the addition of a resonant network, enables soft-switching for the power switches to reduce the switch voltage stress due to high frequency switching operation. The proposed circuit is designed to operate at switching frequency of 1 MHz. The detailed analysis of circuit operation is provided. At last, the feasibility and performance of the proposed battery equalizer are demonstrated through the system implementation and experimental tests of a prototype circuit. Experimental results have shown zero voltage switching (ZVS) is achieved on the switches.展开更多
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
文摘This paper proposes an improved modularizable high-frequency battery equalizer with multi-winding transformer for energy storage systems. The involvement of parasitic components in circuit resonance, along with the addition of a resonant network, enables soft-switching for the power switches to reduce the switch voltage stress due to high frequency switching operation. The proposed circuit is designed to operate at switching frequency of 1 MHz. The detailed analysis of circuit operation is provided. At last, the feasibility and performance of the proposed battery equalizer are demonstrated through the system implementation and experimental tests of a prototype circuit. Experimental results have shown zero voltage switching (ZVS) is achieved on the switches.
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.
