Investigation of the Technical Condition of Stator Winding Insulation of the Synchronous Generator During Its Operation
Modern methods of diagnosing and relaying should allow early detection of damage, and to prevent the release of main equipment of power stations down. Failure as a result of injuries powerful hydro and turbogenerators in a small reserve of power grid is able to cause an avalanche of frequency of system failure, which in turn entail considerable material losses. It is therefore urgent task is to develop new and improve existing means of diagnosing and relaying powerful hydro and turbogenerators. For the development of new devices for diagnostics and protection necessary to identify the causes of the most common types of injuries. In the operation of the stator winding insulation powerful synchronous generator affected a large number of factors that impair its electrical properties. The quality of the insulation effect, as technology manufacturing, installation and maintenance of isolation, and processes in insulating materials and modes of synchronous generator. Construction of diagnosing the technical condition of the stator winding insulation synchronous generator, which would take into account the impact of the above factors are extremely difficult task due to the complexity of building subsystems collection and its high cost. Proposed for the purpose of relaying the stator winding synchronous generator, working in alliance with transformer, from single-phase earth fault and diagnosing the technical condition of the stator winding insulation synchronous generator use integral index - namely, the amount of current leakage through the insulation of the stator winding synchronous generator I = f (U; Rsw; Rt; C). The indexes characterize as the generator mode and state of the main parameters of the stator winding insulation (insulation resistance of the stator winding Rsw, stator winding insulation capacity relative to the ground C and transitional resistance in place of earth fault Rt). Using the proposed indicator can build systems that combine the functions of the device diagnostics and device relaying. Such protection can perform two-stage. The first level of protection will work on symmetric signal with a gradual decrease in the level of insulation below the set value, and the other in the event of sudden ground fault.