Load sharing of the parallel operating adjustable speed generation systems without control signal interconnection

This paper presents a novel method for parallel operation of adjustable speed power-electronic generation systems. The proposed method is based on the well known droop scheme and therefore does not require any additional interconnections between units operating in parallel. Modifications and extensions to the conventional droop scheme are introduced to resolve problems specific for the parallel operation of adjustable speed generation systems. These include novel methods for connecting and disconnecting units to and from parallel system as well as method for sustaining required load sharing between units during sudden load changes. The results from the real laboratory system are presented to justify the proposed methods.