NÁVRH A IMPLEMENTACE METODY MONITORINGU INTERAKCE MEZI TURBOGENERÁTOREM A ELEKTRIZAČNÍ SÍTÍ

Abstract

The work was focused on the research and development of methods, software and the necessary components of the measuring chain for the purpose of analysis and subsequent monitoring of the torsional interaction of the turbine-generator with the events in the electricity network. As described, the torsional interaction is enabled by means of the air-gap torque of the generator, as this is a quantity dependent both on the motion state of the rotor as well as on the current electrical state of the generator. The complexity of the problem is due to the fact that the information on torsional vibration cannot be measured directly, as for example the absolute vibration of bearings, but a special measurement and a relatively complex post-processing must be used. As part of the work, an algorithm was developed and successfully validated for the evaluation of the instantaneous angular velocity, from which the amplitude and frequency of the rotor torsional oscillation can subsequently be evaluated. In addition, some limitations of the proposed method are discussed, as well as limitations resulting from the nature of measuring torsional oscillations with an incremental encoder. The presented case studies prove the existence of significant oscillatory components with a variable frequency originating in the power grid relevant for torsional viration excitation. Furthermore, examples were shown where a sudden change in the state of the electricity network caused a transient excitation of the torsional oscillations of the turbine-generator rotor. A TVMS Torsional Vibration Monitoring System was assembled and programmed in the Labview programming language which has already been deployed on 14 turbine-generators with a total capacity of 3 GW.