Balancing group operation for wind power plants and a pumped-storage hydro generator to maximize expected revenue in consideration of wind power output uncertaintiy

Abstract

The amount of power generated by wind farms (WFs) varies depending on the wind conditions, and its use as the main power source within a power system is thus uncertain. This study proposes a balancing group (BG) scheme that combines the power from WFs with an existing variable-speed pumped-storage hydro generator (PSHG), which possesses a large capacity that can compensate for the variability in WF output. To maximize revenue, power suppliers need to schedule and operate the BG by considering the uncertainty in WF output and the PSHG's operational constraints. In the proposed method, probability density predictions (PDPs) are used to estimate WF uncertainty, and the BG output is scheduled to maximize the expected revenue. The PSHG water-level transition is managed within an operational limit using WF output scenarios derived from PDP results and historical WF output trends. The effectiveness of the proposed scheme was assessed based on revenue for three weeks with characteristic wind conditions, and the results of numerical simulations conducted using several operational schemes were compared using real-world WF output data. The results indicate that higher revenues can be achieved using the proposed operational scheme, thus validating the usefulness of the proposed method.