Hybrid modeling of power electronic system for hardware-in-the-loop application

In real-time simulation applications, hardware-in-the-loop (HIL) within nanosecond time step of large size power electronic systems involving high-frequency control strategy is still a big challenge today. In this paper, we propose a new hybrid modeling approach based on a novel nodal analysis and solving method in order to achieve both fast and accurate real-time simulation. The decoupling method allows dealing with circuit element separately regardless the size of power electronic system. After system matrix is obtained, an innovative approach using Cholesky decomposition is proposed. At last, a comparative case study of traction system in the electrical locomotive train is also presented. For this case study, implementations are made on a Field Programmable Gate Arrays (FPGA) Kintex-7 embedded in National Instruments FlexRIO PXIe-7975. Results obtained show that the proposed modeling algorithm can achieve both accuracy and efficiency within a 50 ns fixed real-time simulation time step. Besides, the comparison with results obtained from Simpower system in Matlab allows evaluating the accuracy of our proposed modeling approach.