Effects of closed-loop control on HF interactions reduction within distributed power systems

The multiplication of power supply sources and loads in distributed power systems (DPS) with several stages of conversion and regulation generates strong problems of interactions between the converters. Some of them could affect the correct operation of these systems. HF interactions within distributed power systems or cascaded converters are usually reduced using large EMI filters. These EMI filters are voluminous, expensive and, sometimes, they disturb the functionality of the converters (stability, step response, bandwidth). However under specific operating conditions, the EMI filters may be greatly reduced thanks to effective converter closed-loop control. Occurrence of HF interactions between cascaded converters or within DPS is presented. Modeling and analysis are performed in order to highlight problems and possible solutions. Experimental results validate the approach. Focus is applied to EMI filter reduction thanks to HF interactions active filtering.