A graphical approach to hydrogenerator governor tuning

Abstract

A number of published works deal with govemor tuning for speed control of hydrogenerators. This work is based on the hypothesis that some system parameters are not known at the design stage. It develops a graph which can be used to predict optimum proportional and integral gains based on four parameters: the time constants of the water column and of the rotor inertia and the selfregulation constants of the turbine and of the loading grid. The pole cancellation method of design is used and the results are posed in an easy-to-use format not requiring the solution of systems of equations. Infolimition on stability limits and comparisons with other work are included.Kev W o r a :

Dynamic response and governor tuning of a long penstock pumped-storage hydropower plant equipped with a pump-turbine and a doubly fed induction generator

“…This mode is referred to as ''Mechanic-water mode" in [25]. A commonly used damping ratio of 0.707 [29] has been chosen in this paper for the lower frequency mode. In Fig.…”

“…8 shows the resulting values of T r and d (1/K p ), in terms of T w , T e for three different values of T m (6, 9, 12 s). Two analytical expressions (29) and (30) have been obtained by means of a regression analysis, giving a good approximation of the T r and d values obtained by applying the FDR criterion. It is important to point out that since T e has shown to have a minor influence on the dashpot time constant, T r curves have been considered as straight lines in the regression analysis; hence the absence of T e in (29).…”

“…Two analytical expressions (29) and (30) have been obtained by means of a regression analysis, giving a good approximation of the T r and d values obtained by applying the FDR criterion. It is important to point out that since T e has shown to have a minor influence on the dashpot time constant, T r curves have been considered as straight lines in the regression analysis; hence the absence of T e in (29). On the other hand, it is also worth mentioning that the temporary speed droop d has proved to be very little sensitive to the chosen values of T m , T e and T w .…”

“…The first one is based on the approach proposed in [13], where the two pairs of poles are forced to coincide. The second one is aimed to provide a given damping ratio [29] to the lower frequency mode [30]. The third one is based on a Pareto approach, which is aimed at finding compromise solutions between the number of oscillations and the mean absolute error of the governor controlled variable.…”

Diagnosis and Vibration Diminishing in Pump Operation

“…From the mathematical point of view, a pumping unit is completely described by means of four equations (rotor dynamics, conduit pressure equation, moment and flow of the pump) [6]. Pump behavior modeling using transfer functions can be achieved only if the pump functioning is around the pump and system operating point [7].…”