Synergetic control theory is introduced into hydraulic generator excitation system (HGES) and hydraulic generator governing system (HGRS) in this paper. Synergetic excitation controller (SEC), synergetic governing controller (SGC) of HGU have been designed. In order to enhance the terminal voltage control and mechanical power tracking performances simultaneously, the integrated synergetic controller (ISC) is also proposed. ISC implements synergetic control of terminal voltage, rotor speed, mechanical input power and guide vane opening. Namely, the ISC is considering both of the excitation system and governing system of hydraulic generator unit (HGU), which can provide control function instead of SEC and SGC. In addition, the control rules of the aforementioned three controllers are deduced from the nonlinear mathematical analytic model of hydroelectric generator unit. At the end of this paper, comparative case studies between the proposed SGC, SEC, ISC and classic PID controller are presented. The results show that the proposed ISC improves the nonlinear HGU system performance with a more accurate precision and shorter settling time in different operating conditions.