The Insulation Department performs tests of insulation systems of windings of high-voltage electrical machines, especially high-power generators and hydrogenerators, for the power and electrical machinery industries.
The Department's greatest success has been the introduction of a new diagnostic method for evaluating insulation systems of high-voltage electric machine stator windings, based on off-line measurements of the intensity of incomplete discharges.
Based on the analysis of test results, mainly the intensity of incomplete discharges, the technical condition of the insulation of stator windings and the degree of its degradation is evaluated. Recommendations are developed for further operation of machines and also recommendations for repair or modernization.
A system for evaluating machine insulation systems has been developed, defining the program of required tests and current criteria for evaluating their results.
The Insulation Department is developing methods for diagnosing machine insulation based on the results of measurements and analysis of incomplete discharges, which form a rich database of insulation systems. These diagnostics have been implemented and are being carried out in most of the country's largest utility power plants and combined heat and power plants, as well as in some industrial plants.
The world's unique database of insulating systems of stator windings of high-voltage electric machines has been created since 1994 and is constantly expanded with data of successive new and operating machines.
The database contains digital records of the parameters of incomplete discharge in generators, hydrogenerators and high-voltage motors, with different types of winding insulation.
Evaluation of the machine's insulation condition is carried out by comparative analysis of the baseline reference parameters obtained in the first measurements and in subsequent measurements repeated periodically. The classification of defects in insulation systems is carried out on the basis of a continuously expanding catalog of defects.
Analysis of changes in the parameters of incomplete discharges allows tracking the process of insulation degradation, detecting hidden defects and pre-failure states threatening to break through during machine operation, which makes it possible to effectively take timely corrective action.
On the basis of a multi-year analysis of the data contained in the database, forecasts of the life of machine insulation are developed. An application called Elektrowiz has been developed to visualize the dielectric parameters of generator winding insulation.
The Insulation Department conducts work in the development of technologies for the production of new and upgraded insulation systems for high-voltage windings of rotating electrical machines. Particularly noteworthy is the improvement of solutions for the anti-stress protection of windings. The department offers to carry out technological supervision in the production, overhaul and modernization of turbo- and hydrogenerators, ensuring high quality workmanship, guaranteeing many years of trouble-free operation of machines.
We determine the necessary scope of repair or modernization work, establish quality requirements for the selection of materials and manufacturing technology for winding insulation systems, and establish the required criteria for inter-operational and final acceptance. Particularly important in production is our assessment of the quality of the insulation systems of winding elements (rods or coils) on the basis of the intensity of incomplete discharge, their acceptance and transfer to the winding process. The final assessment is made on the basis of our acceptance tests of the finished machine on the work bench.
As an independent testing unit, we provide a reliable assessment of the quality of the manufactured stator winding and the entire machine. Our assistance in the technical evaluation of tenders can be useful in selecting the best manufacturer or contractor for generator overhaul/modernization.