Repetitive control and virtual bleeder resistor for AC generator sets with harmonic-sensitive loads

Low and medium power full-digital AC generator sets are largely used in both industrial and civil fields. During the last years, more demanding applications for AC generators have emerged. They require more power combined with a cleaner voltage source. Consequently, particular care is requested for both the mechanical and electrical design of a new AC generator set, as well as a keen choice of the digital control strategy. This paper presents a control technique suitable for gasoline engine-driven AC generator sets, which minimises the voltage harmonic distortion by means of repetitive control, while assuring good performances in a very wide load range by means of a virtual bleeder resistor (VBR). Simulation and experimental results confirm the effectiveness of the proposed strategy.