This paper presents new techniques of Automatic Generation Control (AGC) technology which are employed to increase the certain demand of power system stability and control. Today, power system control operation is fully automated with an Automatic Generation Control (AGC) technology and improves the reliability, productivity and efficiency of power industry. The power generating equipment can be controlled by maintaining the power system frequency at constant value. And power system frequency control is achieved by Automatic Generation Control (AGC) and governing systems of individual turbine-generators. This achieves the automation of whole power plant based on automatic control of water-turbine generator. Therefore the mechanism of Automatic Generation Control (AGC) makes operation limitation condition units that ensure the safe operation of power plant with the principle of Energy Management System and primary functions. At the time of carrying out these functions, it is necessary to avoid the frequent start/stop of units caused by short-term load fluctuation of power system and detail problems are discussed in the paper. At the end study is also focused in engineering problems and target function of Automatic Generation Control (AGC) in hydropower plant.

Condition-based maintenance is a kind of maintenance which conducted before fault by judging device exception and predicting device fault based on device condition information provided through monitoring device condition. The analysis result of fault diagnosis technology and production management information system which has namely arranged the maintenance plan. The implement device maintenance in light of device health condition due to prevents excessive maintenance or disrepair of device to the utmost extent. During operation, primary device of hydropower plant constantly suffers from sand abrasion, cavitation damage, mechanical wear and other mechanical or electrical damage, which reduces the efficiency of generating equipment and shortens the service life. If timely monitoring and diagnosis and appropriate maintenance are not provided, accident may be induced and cause great economic losses; to make primary devices for production and transmission of electric energy of hydropower plant have high reliability and be in good operating conditions, such primary devices must be maintained. The aim of this paper is to define the gradually improving sensor and monitoring technology which offer the possibility of condition-based maintenance of hydroelectric generating unit and the extraction and analysis methods of fault characteristics. Therefore discussion is summarized briefly on composition, configuration and functions of Condition-based Maintenance System (DSS). And also describes the short introduction of Condition-based Maintenance (DSS) system in typically project of Songjianghe Hydropower Plant as used for primary devices.

An Integral part of generator is Excitation System and new technology of Excitation System has been developed utilizing a power sources. The most important a portion of electric power system is synchronous generator due to it is the source of electrical energy and energy transformation is possible only when generator excitation exists. The generator excitation systems work when generator excitation system operates a dc charge to the generator heads to energize the field of magnetic around them to enable the electricity that should be generated. There are brushless and brush-type exciters and generators are built in exciters or charge can be established from any external source. This paper presents the control and configuration of synchronous generator excitation system as current mainstream technology, which is widely designed for feeding of turbo generator excitation winding with auto- regulated DC in generator operation, control normal and emergency modes. In this paper discuss appended on excitation system models of synchronous generator and emphasis on drawbacks, different possibilities to regulate generator excitation, de-excitation systems and overvoltage Protection with special newly developed nonlinear system regulation. And also append short descriptions of functions, compositions, Structure and Working Principle of Generator Excitation System.