Very small hydroelectric plants-their influence on the supply network

Interest in building small hydroelectric power plants is growing of late. The problems that occur are mostly caused by the lack of national standards, which should more clearly define the allowed influence of such power stations and their generators on power network voltage distortion. Investors often do not know whether it is necessary to invest in extra equipment for meeting voltage and current quality standards. The authors made some measurements of the influence of very small hydroelectric power stations in the field and in their laboratories, which are described in this paper.