Research On Small And Medium-sized Turbo-generator Self-shunt Excitation System Transformation And Design Problems

Excitation control system is an important part of synchronous generator. The quality of its characters directly influences the reliability and stability of operation for generators and power system. This paper, through the detailed analysis of problems appeared in the design process of the integrative improvement of excitation system, can effectively regulates the design proposal of excitation system reform, and avoids that the unit don’t match the actual generator operation, unable to meet the on-site requirement. Meanwhile, this paper hopes to provide some references for power plants and other owners when preparing for the preliminary technical investigation.This paper has studied the excitation reform project of the small and medium-sized synchronous generator unit, and divides the self-shunt static excitation system into four parts for analysis, like excitation transformer, excitation regulator, power rectifier and de-excitation. The part of excitation transformer mainly explains the determination of transformer capacity and the specific technical terms of guard signal configuration. Combined with the actual situation of transformer unit, it is also demonstrated item by item. The part of excitation regulator focuses on the specific function of the protection, and explains the important role played by excitation system as an essential equipment of electric system. The part of power rectifier mainly analyzes three aspects, like the components selection in the cabinets, the calculation of calorific value of the cabinet, and how to make sure it is economical and meet the output. Finally, with specific examples, the part of de-excitation analyzes the conventional de-excitation loop, and clarifies those specific problems that should be paid attention in the design process of reform project.Proposed to select some typical engineering projects of the small and medium-sized synchronous generator as research object, this paper aims to use the method of theoretical calculations, determine the reasonable parameters of main components, comprehensively considering the engineering practice, and finally determine the reasonable solution for the engineering project. The difficulty of this research proposal is that the selected excitation reform program must be typical. The differences between different reform programs should be fully explained, ensuring that this paper has a certain degree of universality.The innovation point of this paper embodies the aspect of research angle. In the past, the discussion of generator excitation selection mainly focus on two categories, one is research on principles of excitation system, which mainly focused on the protection of excitation regulator. Another one focuses on listing a project implementation plan, which seldom analyzed from the aspect of design level. This paper emphasizes on making theoretical issues more specific, and aims at providing guidance to the project practice through specific design. The advantage of this analysis plan is that it doesn’t need precious calculation and descriptive text like the previous theoretical essays, but easier to grasp the essence of the problem compared with explaining a project implementation process.