DC Power Networks with Very Low Capacitances for Transportation Systems: Dynamic Behavior Analysis

It is known that conventional analysis based on average models can be used only if the cutoff frequency of the filter is much lower than the switching frequency. For networks with very low capacitances, the cutoff frequency is close to the switching frequency so other tools are required for analyzing the behavior of the system. Such a tool is proposed in this paper and is applied to predict chaotic, multiperiodic or stable behavior of cycles defined by state variables of the system. A permanent magnet synchronous motor-drive system constituted by a dc power source supplying an LC filter connected to a tightly controlled motor is studied. A very low capacitance is provided such that the switching effects due to power electronics device can no more be neglected. Experimental results confirm the validity of the proposed tool.