Short-term frequency response of power systems with high non-synchronous penetration levels

In addition to the generation and transmission of electricity, the reliable and secure operation of power systems also relies upon various ancillary support services supplied by power plant and loads. The portfolio of required support services has historically been well understood. However, as conventional power plant are displaced by modern variable renewable generation, such as wind and solar, so too are those traditional ancillary support services. As a result, new support services are required and changes in operational behavior are necessary. The impact of increased variable generation levels on one such support service category, short-term system frequency response, is considered here. The evolution of power system behavior with respect to this service is assessed, with potential solutions to the associated challenges explored, and pertinent future questions in this area highlighted. (C) 2014 John Wiley & Sons, Ltd.