Design of a new cooperative harmonic filtering strategy for the distributed generation systems

The increasing demand of premium electric power, in terms of quality and reliability, and the emerging new energy technologies have led to the development of distributed generation systems. With the penetration of power electronics equipments growing rapidly, it can be expected that a large portion of the load within the distributed generation system is nonlinear in nature, and the resulting harmonics pollution needs to be addressed. This paper proposes a new cooperative harmonic filtering strategy for the interface converters of distributed generation sources. A droop relationship between the harmonic filtering command and the harmonic VAr consumption of each interface converter is established in the proposed strategy so that the overall harmonic filtering workload can be evenly shared without any communications. The operation principle is explained in this paper. Simulation and laboratory test results are provided to validate the distributed harmonic damping capability of the proposed strategy.