Case 1: Taohuashan Hydropower Station is located at the branch stream of Qing River of Hefeng county in Enshi autonomous region of Hubei province. It is the second grade hydropower station of ladder development for Qing River branch stream basin. With the installed capacity of 3200kw, the station is equipped with two units of hydro turbine generator of voltage 6300V at outlet end of the unit, one set of main transformer for voltage rising, one set of transformer for self use and one loop of circuit. JME's comprehensive automation system controlled by computer is used for monitoring and protection.

It is designed with distribution type and has high accuracy and strong liability. The main functions are as follows:

A. To collect analog quantity, pulse quantity and switching times during the overall production, and to record and keep the data.

B. To monitor the operation parameters and equipment conditions of the main mechanical and electrical equipment.

C. To realize the automatic control of the equipment, and to operate or adjust the equipment according to the request of upper authority or the requirement of the station operation patterns.

D. Capable of carrying out closed circulation adjustment as per the given power value, and ensuring the operation with given loading value.

E. According to the total power (load curve) given by control center and the operation characteristics of the unit (frequency, vibration zone, time for off operation ) and aming at minimizing the water consumption, it can establish mathematics mould to calculate how many units should be put into operation under the present condition of water head and to calculate the economic distribution of the load for operation units. It also can conduct the orders of automatic start, stop, and load adjustment to realize closed circulation control.

F. Be of the functions of automatic voltage control, automatic frequency adjusting operation, automatic low frequency starting and high frequency reducing output.

G. Calculation of electricity volume for generation and output at any time, the operation condition of various kinds of equipments and the examination statistics of different performances index.

H. To provide micro-computer relay protection for the primary equipments, such as generator, main transformer, transformer by self use and PT, etc.

I. To realize the automatic control for the operation of power station, and to realize the automatic or manual printout of the report forms.

I. To realize of communication connection between ladder management and power system management, and to realize remote control of the station.

 

Case 2. Computer Monitoring System and Carrier Communication System of Mujarli Hydropower Station in Burundi

Mujarli Hydropower Station is located at west of Burundi , 23km far from the Capital. This project is composed of concrete dam, water tunnel penstock, hydropower steel tube and hydropower station. The building of the station is located at 4.4km from the lower stream of dam. The designed head of the station is 274m and the maximum of the water flow is 3.776m /s. Four units of propeller type turbine generator with total installed capacity of 100,000KW were designed for the station.

It was requested that the micro-computer protection and monitoring system would be used to collect, process the data for all the station equipment, and to monitor and record the operation condition automatically. In accordance with the operation patten of the station, automatic control of all equipments should be executed, such as, the normal start and stop of the unit, automatic stop for accident, active power and reactive power regulation of the unit, the operation of circuit breaker and public equipment (such as main transformer, circuit and PT). The automatic control for station operation has been realized including the automatic record operation, the registration and storage of the log or memorandum, the recording and storage of the parameters of the station equipment or rectified value, and automatic printout of all the report forms.

The French dialogue has been used for the interface of man-machine (free language selection). Each operation step has clues with no need to remember equipment number and operating instruction to avoid operation by mistake resulted from wrong memory. All the buttons shall be locked automatically under the condition of non-operation. Multi-protection measures for failure shall be adopted for some key operations. The system adopts anti-interference measure by various hardware and software, which ensures the safe operation and communication of the system, and the stability of the system.

After completion of the project, the examination team arrived at Mujarli Hydropower Station on August 31, 2001. They made inspection on the construction site firstly. On the basis of debriefing the reports from engineers from construction, design and supervision units, they made examination for each unit construction and tested for equipment operation. They arrived at an evaluation afterwards that the micro-computer monitoring system has the functions of accurate data measure, simple operation, perfect operation records and orderly management. Its all functions conform to the requirements of design. It also provides the safe and reliable operation of the unit. The quality of 9 items of unit construction is excellent with 100% qualified rate which meets the technical requirements.