Abstract: At present, closed-loop regulation using a monitoring system is the main method for regulating the power of hydropower units. To simulate the active power regulation behaviors of such a system, this paper develops a mathematical model including LCU, governor, water conveyance system, and hydro turbine; and verifies its accuracy against measurements in-situ. Based on simulations, we analyze the influence of the monitoring system and governor parameters on the transient process of active power regulation. Results show that the system’s pulse width parameter β mainly affects those adjustment processes that are close to the target value in active power regulation, and that a smaller β leads to larger regulating amplitudes of guide vane opening. A short pulse period T accelerates the regulation. A smaller maximum width Tkmax leads to smaller regulating amplitudes of the opening in each cycle, thus prolonging the total regulation time; while the minimum width Tkmin has no effect on regulation speed but affects regulation accuracy significantly. The speed of guide vane opening regulation is determined by the parameter Tiy. A large Tiy slows down power regulation, while reducing Tiy can increase regulation speed but will also increase the inversely regulated power value. Specifying a too small Tiy may lead to overshoot and even oscillation in active power and guide vane opening.

Key words: hydraulic machinery, active power regulation, AGC, numerical simulation, hydropower station monitoring system