Investigation of Multi Feed In of Active Infeed Converters for Indus-trial DC Micro Grids with Voltage Droop Control

This paper investigates multi feed in operation of highly efficient SiC-based active infeed converters (AIC) for industrial DC micro grids using voltage droop control. For the demonstration of multi feed in operation two identical three-phase power factor correction (PFC) converters with different droop curve settings are utilized. The AICs are designed for a nominal power of 5 kW. A DC bus voltage range from 400 to 800 V is specified while the desired nominal DC bus voltage is 650 V. Multi feed in operation with implemented voltage droop control shows, that circulating currents between the active infeed converters occur, which cause problems due to high current peaks even on low load operation. These circulating currents are analysed.