COOLING OF LARGE ROTATING MACHINES IN HIGHLY RENEWABLE ELECTRICITY SYSTEMS

In highly renewable electricity systems, large rotating machines such as turbogenerators and synchronous condensers operate at a varied operating range than those in the traditional electricity systems. However, in many cases, it has been observed that this has an enduring effect on these machines by higher thermo-mechanical stresses while causing increased lifetime losses. Hence, there is much more need than ever to revisit the various cooling methods traditionally adopted for large rotating machines. This paper addresses the challenges due to the emerging operating characteristic of large rotating machines and describes the recent technological advancement in the cooling techniques for large rotating machines.