Uprating And Retrofitting Capacity Of QFS Type 300MW Turbogenerator And Its DCS Reconstruction

Based on the 300MW unit of Zouxian power plant, combined with this project' s fact, this paper researches the uprating and retrofitting capacity of QFS-300-2 type 300MW turbogenerator unit and its DCS reconstruction .This paper introduces the general situation of 300MW QFS type turbogenerator unit and its control system before the reconstruction. QFS type turbogenerators have some original problems , such as large magnetic lenkage at the end winding due to configuration , higher local temperature of stator' s end press ring, incapable of leading phase operation and low efficiency of generator, not matching capacity of the 335MW steam turbines etc, it is necessary to uprate and retrofit the 300MW QFS type turbogenerator.This paper analyses the factor which limits generator' s capacity and the problems which needed to solve and the ways which can be used in the project. Tong-ma epoxy glass mica paper tape possess many good properties, As this material is thiner than the old , cross-section of the generator stator bar can be larger than ever with the application of it . The efficiency of the generator can be improved. With the further improvement of the electronic technology, it is of great significance in the improvement of automation and management level of power plant by using DCS system to accomplish the control of 300MW thermal power unit .Based on the fully research above, this paper introduces the major measures adopted for uprating and retrofitting and discribes the distribute control system design scheme in detail. The efficiency of the generator can be improved. Stator insulation class rises to F class and temperature rise limites within B class.The project adopts I/A device of Foxboro Company. This part discribes the distribute control system design scheme in detail and brief introduces the DCS' structure, function, characteristic, distributed fashion and its software and hardware.After retrofit, the modul test of stator' s end winding, temperature rise test of generator at maximum load, leading phase operation test of generator and loss and efficiency test of generator were carried out . Some original problems of QFS type generator, such as large magnetic lenkage at the end winding due to configuration , higher local temperature of stator' s end press ring, incapable of leading phase operation and low efficiency of generator etc.problems were solved.These industrial experiment results shows that the operation of generator was reliable,the capacity was raise from 300MW to 335MW, up 11. 67%, both the economics and peaking performance were elevated obviously, the automation and management level of power plant was greatly improved . The design method presented in this paper is effective, and the unit performance is satistactory.There are more than twenty of this type generator all over China. This project affords experience and reference for the retrofit of similar type generators.At last, the chapter gives the suggestion of further improvement. In order to assure operating properly in phase lead, this article introduces the run qualification of generator in leading phase operation. This paper also introduces the setting principle for the low exciting limit unit.