(1) Turbine
(hydraulic motor): Impulse type and counter-impact type are commonly used.
(2) Generators
(hydraulic motor): most of the generators use synchronous generators with low speed, generally below 750r/min, and some only have tens of revolutions/min. Due to low speed, the number of magnetic poles is large. Structural size and weight are large; Installation forms of hydraulic generator units are vertical and horizontal.
(3) Speed regulation and control device (including speed governor and oil pressure device): The function of speed governor is to adjust the speed of turbine so as to ensure that the frequency of output electric energy meets the requirements of power supply and to realize unit operation (start-up, stop, speed change, load increase and load reduction) and safe and economic operation. Therefore, the performance of the governor should meet the requirements of fast operation, sensitive response, fast stability, convenient operation and maintenance, and it also requires reliable manual operation and accident shutdown device.
(4) Excitation system
(hydraulic motor): Hydraulic generator is generally an electromagnetic synchronous generator. By controlling DC excitation system, voltage regulation of electric energy, active power regulation and reactive power regulation can be realized to improve the quality of output electric energy.
(5) Cooling system
(hydraulic motor): The cooling of small hydraulic generator mainly uses air to cool the surface of generator stator, rotor and core by ventilation system. However, with the increase of the capacity of the single generator, the heat load of the stator and rotor is continuously increased. In order to increase the output power per unit volume of the generator at a certain speed, the direct water cooling of the stator and rotor windings is adopted for the large-capacity hydraulic generator. Or the stator windings are cooled with water and the rotor is cooled with strong wind.
(6) Control equipment of power plant: The main control equipment of power plant is computer, which realizes functions of parallel network, voltage regulation, frequency regulation, adjustment of power factor, protection and communication of hydraulic generator.
(7) Braking device
(hydraulic motor): Hydraulic generators with rated capacity exceeding a certain value are equipped with braking device. Its function is to apply continuous braking to the rotor when the speed drops to 30%~40% of rated speed during generator shutdown so as to avoid burning the bearing shells due to oil film damage at low speed. Another function of the brake is to jack up the rotating parts of the generator with high-pressure oil before installation, overhaul and start-up. The brake system uses compressed air for braking.
