Advanced control strategies for pumped storage plant

Pump storage hydropower stations provide a highly flexible means of managing a power system by virtue of their operational flexibility. In particular, their ability to respond rapidly to changes in system loading means that they are often used for the control of network frequency. This in turn requires that their operation, unlike that of a conventional base load station, must be more responsive while not introducing any instabilities into the network. Historically, pump storage hydro-power stations have, when used for frequency control and load management, relied for their control on machine governors based on conventional PID controllers implemented initially in analogue form, and more recently using digital means. While such controllers have given a good response, as the operational demands on the network has increased in relation to factors such as responsiveness and load scheduling, so the limitations of such controllers in terms of their ability to respond to these increased demands are being revealed. For this reason the possibility of using enhanced control strategies based on the use of a modified form of the conventional PID governor together with a governor based on the use of fuzzy logic are being considered for application in the United Kingdom at the Dinorwig plant operated by First Hydro Ltd in North Wales. The development of these advanced controller concepts is based on the availability of a comprehensive model of the Dinorwig plant developed by the authors which enables the impact of the advanced governor concepts to be evaluated.