Permanent rotor vibration diagnostic monitoring system in HPP Dubrovnik automatically records vibration condition vectors during all operating conditions, including overspeed test, performed regularly after outage as part of protection system adjustment. Based on these records, calculation of vibro-dynamic rotor behaviour was developed, in order to determine critical rotor speeds and simulate vibrational behaviour during theoretical overspeed. As a result of this procedure, additionaly, stiffnesses of bearings, stator and foundations can be determined, as well as vibrating masses of stator and foundation. The damping characteristics are result of the calculation, too. Based on results of experimental determination of HPP Dubrovnik turbine-generator set rotor critical speed and simulation of vibrational behaviour during theoretical overspeed it is shown that that first critical speed lies between regulation and theoretical overspeed. In spite of that, vibrational response, in case of theoretical overspeed occurence, will not be harmful for the machine. These results, presented in the article, can be accepted as a basis for definition of rotor design criteria, due to a fact that first critical speed will be, for a lot of machines, over theoretical overspeed level. In such situation, it is possible correctly to estimate and achieve acceptable dynamic behaviour of the machine.

Monitoring system of electrical quantities was installed on three generators and seven overheads in CCCPP TE-TO Zagreb. System is providing permanent monitoring during stationary operation (currents, voltages, THD, power factor, phase symetry, active and reactive power) and automatic recording of all transients in 10 seconds period (1 second pre-trigger recording and 9 seconds after trigger occurence). As the example of this system characteristics the recordings of major power system disturbance which occured on 2003 January 22 are presented and explained in this article, with some additionall system analysis capabilities (power dynamic analysis during transient).

Some positive expiriences and advantages of this system are discussed in the article (using already mentioned disturbance example), with some suggestions of further system development, mainly concerning application of this type of monitoring on non-electrical quantities as well.

Application of computers in energy production enabled permanent monitoring of practically all values relevant for production, supplying the personnel with data neccessary for energy production increase and operational costs reduction. Usually, diverse power plants’ subsystems are monitored by diverse computers dedicated for monitoring and diagnostic.

CoDiS-Hydro system is designed to monitor all values relavant for energy production in power plant on a single diagnostic computer, which can easily be included in a power plant’s computer network, and send data to central computer, or exchange data with process computers. This system is installed and operational in HPP Dubrovnik.

Systems for automatic transient recording 1 second before and 9 seconds after trigger conditions were met, are operational on several plants in EES RH. These systems provides simultaneous and continuous recording of electrical quantities (generator and network currents and voltages), and has possibility to record some other interesting data (e.g. vibrations). In addition to transient recording (waveforms recording), system provides continuous monitoring of electric energy quality, calculating THD (total harmonic distortion) factor, phase symmetry angles, cosφ (averaged and for each phase), power angle (for generators), with possibility of analysis results trending.

Since those monitoring systems' installation, several hundreds of transients were recorded automatically. Additionally, the systems were very useful during the phase sequence adjusting on interfaces between Croatia and Hungary and between Croatia and Slovenia. Results of the analysis of some records were used during some adjusting of G5 and G6 units in TE-TO Zagreb.

One of the advantages of these monitoring systems is their network-friendly design. The article describes the program for browsing recorded data and controlling the functions of systems located on distant plants, which is installed on a computer in remote control center of HEP Transmission, being connected to systems in HPP Dubrovnik, TE-TO Zagreb and HPP Varaždin with several additional connections planned.

Permanent diagostic monitoring system, installed in HPP Peruća is dedicated for mechanical, electrical and hydraulic measuring data monitoring. System performs continuous analysis of turbinegenerator set measured data, calculates and records results in a condition data-base (condition vector). Monitoring of transient phenomena is performed simultaneously as well, launching a recording of a portion of complete signal waveforms when trigger conditions were met.

System performs monitoring of relative shaft and absolute bearing housing vibrations, stator core vibrations and rotor axial thrust, bearing temperatures, rotor poles' magnetic flux, generator air gaps, currents and voltages before and after transformer, exciter voltage and current, efficiency of turbinegenerator set and turbine cavitation.

The system is functional on tubine-generator set 1 in HPP Peruća, and some basic but very important data base of macine bahaviour already exists (new machine reference data base) as well as some interesting expiriences with system configuration and application. In the article, ther are description of the installed system and short review of the first measurement results.

Permanent on-line monitoring systems, installed on croatian power plants are designed to monitor vibrational, electrical, temperature and hydrodynamic quantities of turbine-generator sets by means of transducers mounted on stator parts. Monitoring of quantities measured on turbine-generator sets rotor was not applied, because there was not possible efficient signal transfer from rotating part of the machine.

System, described in this article, was developed mainly for application on two power plants (HPP Vinodol and HPP Dubrava) with intention to realize wireless signal transfer from transducers mounted on generator's rotor. Applying this system, excitation voltage and current are measured directly. Permanent monitoring of insolation resistance, stator geometry (air-gap sensor mounted on rotor), magnetic flux in air-gap (magnetic flux sensor mounted on rotor) and rotor temperatures are enabled as well. Design and installation of the system, applied on both power plants, are described in the artiucle. Some of the most interesting results, concerning measurements of mechanical and electrical quantities in air-gap achieved by the system are shown as well.

Some experiences in generator poles magnetic flux and air-gap monitoring in power plants Varaždin and Dubrovnik are presented in the article. Besides recording and analysis of the magnetic flux and air-gap signal waveforms, it is important to determine and apply measured data estimation criteria and to define criteria of irregular condition appearance recognition.

Lacking clearly defined and approved criteria for this type of condition monitoring, authors suggest one possible approach to monitoring methods, normal condition determination, possible criteria of pole support structure failure (air-gap monitoring) recognition and failures in pole windings as well (magnetic flux monitoring). Discussed criteria are applied in permanent diagnostic monitoring systems in HPP Varaždin and HPP Dubrovnik.