Introduction of Hydro Turbine Governor:

Hydro turbine governor is one of the important auxiliary equipments in a hydroelectric generating set, a general term that describes one or more devices consist of realizing adaptive water-turbine and responsive control mechanism and indicators. Cording to the detection of hydroelectric generating set speed deviation to switch control into the turbine flow, water-turbine guide institutions adjust the rotate speed and output. Hydro-turbine governing system is a close loop system that consists of controller, hydraulic servo system and regulating object, usually controller and hydraulic servo system are collectively referred to as the turbine speed governors.

Functions of Hydro Turbine Governor:

* It can automatically adjust the rotating speed of hydroelectric generating, keeping them running within the allowable deviation rated speed, so as to meet the requirements of power grid frequency quality.
* It quickly makes hydroelectric generating set automatically or manually starting to adapt to the power grid load's increase and decrease, and the needs of the normal downtime or emergency stop. 
* When it runs in parallel with hydroelectric generating set in the power system, the governor can be automatically scheduled for the load distribution, and make each unit to achieve economic operation. 
* It can meet the combination needs of both the paddle and impulse water turbine. 

Working principle of Hydro Turbine Governor:

By comparing the rotational speed signal (frequency unit) to the power grid frequency (for a given frequency), based on its difference, the governor gives the electro-hydraulic converter an operating signal relay device on or off (command) to control the turbine water flow, and in this way achieves the regulation of turbine speed.

Classification of Hydro Turbine Governor:

According to the applicable unit of speed, governors are classified into: impact governor, monotone, dual regulating. The impact governor applies to the impulse turbine unit; the drab applies to the mixed-flow turbines or axial flow turbine generator set; the dual governor applies to the movable propeller turbine and bulb tubular turbine with the adjustment of wheel blade.
It also can be divided into the mechanical governor (i.e., ST and T), electric speed governor (DST and DT), microcomputer governor (WST and WT), etc according to their governing components.