SISTEM DE MONITORIZARE CU ARHITECTUR? CLIENT-SERVERPENTRU AMENAJARE HIDROENERGETIC?

摘要

The paper presents a computerized measuring system, based on up-to-date method, for surveying andrnmonitoring of the hydroelectric power stations HPS. At present hydroelectric power stations arernundergoing a modernization process for operating optimization. One of the main ways to improve arnhydropower development (hydropower station) is to equip it with SCADA-type acquisition and controlrnsystems. The system is based on an architecture distributed an three hierarhical levels: the process,rnlocal (located in the HPS) and the territorial dispatching level (located in Hydropower Dispatcherrnlevel). The system includes programable automatic equipments, intelligent electronic devices, datarntransmission system and computers. The monitoring system connects three distinctly differentrnenvironments. The substation, where it measures, monitors, controls and digitizes; the Control Room,rnwhere it collects, stores, displays and processes substation data; the Dispatcher Center, where itrnstores and displays incoming data. A communications pathway connects the three environments.rnCentral computer of the data acquisition system, located in the hydro power plant, providesrnmeasurements performance according to a preset program, the instrumentation existing at this timernand remote communications by RS485 bus, using Master-Slave architecture and IEC 11 70, ModbusrnRTU, ASCII protocols. The system includes measurements of the water levels, temperatures and mainrnelectrical parameters of the hydrogenerator. The system operator views data and messages through arndisplay on "view station". Besides these basic functions the Control Room computer archives datarnand displays selected data sets, such as logs in special ways for the operators. Complete or partialrnmeasurement sets may be ordered automatically from the control computer. Computer program hasrnmore functions among which data processing using preset procedures, drawing up tables and chartsrnfor main parameters in time variation, storing in database. The system monitors the incoming streamrnof analog variables that are outside prescribed limits with warnings and alarms to alert the systemrnoperator to potential problems. Data is screened for "bad" (out of reasonablity limits) data as well.rnThe remote communication server gathers the information from the hydro power plants connected byrnmeans of modems over GSM or phone lines. The dispatcher level is in charge of collecting andrnarchiving the data coming from the hydro power plants and presenting this data to the dispatchers.rnThese are real and reactive power flow (watts and vars) voltages and currents and otherrnmeasurements, like water levels. Analog data is refreshed periodically so that the operator can bernassured the data on his screen is relevant. A modern information technology architecture distributesrnthe computing resources into clients and servers. Winsock control comes with Visual Basic 6 and isrnused to create flexible applications that access the low-level functions of the Transmission ControlrnProtocol/Internet Protocol (TCP/IP). There are two separate applications, one of which is a serverrnand the other is a client. Both client and server interact with each other to exchange data on-line.rnClient sends a request to the server and the server which is connected to a database retrieves therninformation requested by the client from the database and returns the requested information back tornthe client. Database is located in the HPS, on a machine different from the one that hosts the clientrnapplication, located in Hydropower Dispatcher level. Benefits when developing such computerizedrnmeasuring system are being highlighted.