1、 Division of capacity and grade of hydro generator
At present, there is no unified standard for the classification of capacity and speed of hydro generator in the world. According to China’s situation, its capacity and speed can be roughly divided according to the following table:
Classification rated power PN (kw) rated speed NN (R / min)
Low speed medium speed high speed
Micro hydro generator < 100 750-1500
Small hydro generator 100-500 < 375-600 750-1500
Medium sized hydro generator 500-10000 < 375-600 750-1500
Large hydro generator > 10000 < 100-375 > 375
2、 Installation structure type of hydro generator
The installation structure of hydro generator is usually determined by the type of hydraulic turbine. There are mainly the following types:
1) Horizontal structure
Horizontal hydro generators are usually driven by impulse turbines. Horizontal water turbine units usually use two or three bearings. The structure of the two bearings has the advantages of short axial length, compact structure and convenient installation and adjustment. However, when the critical speed of the shaft system can not meet the requirements or the bearing load is large, the three bearing structure needs to be adopted. Most domestic hydraulic turbine generator units belong to small and medium-sized units. Large horizontal units with a capacity of 12.5mw are also produced. Horizontal water turbine generator units produced abroad are not rare with a capacity of 60-70mw, while horizontal water turbine generator units with pumped storage power stations can have a single unit capacity of 300MW.
2) Vertical structure
Vertical structure is widely used in domestic water turbine generator units. Vertical water turbine generator units are usually driven by Francis or axial-flow turbines. The vertical structure can be divided into suspension type and umbrella type. The thrust bearing of the generator located at the upper part of the rotor is collectively referred to as suspended type, and the thrust bearing located at the lower part of the rotor is collectively referred to as umbrella type.
3) Tubular structure
The tubular turbine generator unit is driven by the tubular turbine. Tubular turbine is a special type of axial-flow turbine with fixed or adjustable runner blades. Its main feature is that the runner axis is arranged horizontally or obliquely, and the flow direction is consistent with that of the inlet pipe and outlet pipe of the turbine. Tubular Hydrogenerator has the advantages of compact structure and light weight. It is widely used in power stations with low water head.
3、 Structural components of hydro generator
Vertical hydro generator mainly includes stator, rotor, upper frame, lower frame, thrust bearing, guide bearing, air cooler and permanent magnet turbine.
Post time: Nov-02-2021
