计及保护和安全控制的水轮发电机组电气制动方法及应用

发布时间：2018-04-16 02:01

本文选题：电气制动力矩控制 + 继电保护　；参考：《重庆大学》2014年硕士论文

【摘要】：单独采用机械制动系统的水轮发电机组，当停机投入机械制动系统后主要依靠制动块和制动环产生的摩擦力降低机组转速至停车，制动块在刹车过程中容易产生磨损并会释放大量的粉尘，特别是对于频繁起停的水轮发电机组，还可能因摩擦制动过程中产生的发热导致制动环变形，制动环和制动块的磨损情况也更为严重。因此对机组制动系统进行电气制动的研究是很有必要的。论文首先从电气制动方法和电制动力矩控制两个方面对水轮发电机组的电气制动进行了全面的分析研究。论文针对三种不同电气制动方法的特性及优缺点，总结出不同电气制动方法的应用场合；对电气制动的电制动力矩进行了详细的理论分析和公式推导，据此得到电气制动两个阶段的控制方案，并绘制出制动电流及制动力矩随转速变化的特性曲线。根据课题研究需要，论文还对电气制动过程对继电保护和电气闭锁控制的影响进行了分析。水电站内受电气制动过程影响的保护包括：发电机定子接地保护、发电机纵差保护、发电机负序电流保护、发电机误上电保护和发电机-变压器扩大单元继电保护，论文还对机组电气闭锁控制风险进行了阐述，，针对分析情况，给出了相应的应对措施。结合对本课题理论部分的研究和天生桥二级电站水轮发电机组电气制动改造的需求，论文对该电站电气制动改造的具体实施方案进行了详尽的分析和阐述。从机组制动方式改造必要性、技术可行性、设计方案选择以及主要设备选型等方面给出了该电站电气制动系统改造的详细分析；考虑电气制动对电站继电保护及电气闭锁控制的影响，结合天生桥二级电站的实际情况提出了对继电保护影响的控制措施，并对电气制动控制系统的风险进行评估，提出基于安全导向的自动控制策略和闭锁逻辑原则。本课题的研究成果可为今后大容量水轮发电机组的电气制动设计和改造提供参考。
[Abstract]:When the hydrogenerator set with mechanical braking system is put into the mechanical braking system, it mainly depends on the friction produced by the brake block and the brake ring to reduce the speed of the unit to stop.Brake blocks are prone to wear and release a large amount of dust during the braking process, especially for hydro-generator sets that frequently start up and stop, and may also cause the brake ring deformation due to the heat generated during friction braking.The wear of brake ring and brake block is more serious.Therefore, it is necessary to study the electric braking system of the unit.In this paper, the electric braking method and the torque control of hydraulic turbine generator are analyzed and studied.According to the characteristics, advantages and disadvantages of three kinds of electric braking methods, the paper summarizes the application of different electric braking methods, and makes a detailed theoretical analysis and formula derivation of the electric braking torque.According to this, the control scheme of two stages of electric braking is obtained, and the characteristic curves of braking current and braking torque varying with rotational speed are plotted.According to the need of the research, the paper also analyzes the influence of the electric braking process on the relay protection and the electrical locking control.The protection affected by the electric braking process in hydropower station includes: generator stator grounding protection, generator longitudinal differential protection, generator negative sequence current protection, generator false power protection and generator transformer expansion unit relay protection.The paper also expounds the control risk of the electrical locking of the unit, and puts forward the corresponding countermeasures in the light of the analysis.Combined with the research of the theory part of this subject and the demand of the electric braking transformation of the hydroelectric turbine generator set of Tianshengqiao Hydropower Station, the specific implementation scheme of the electric braking reform of the power station is analyzed and expounded in detail.From the aspects of necessity, technical feasibility, selection of design scheme and selection of main equipment of the braking mode of the unit, the detailed analysis of the revamping of the electric braking system of the power station is given.Considering the influence of electric braking on relay protection and electrical lock control of power station, combined with the actual situation of Tianshengqiao secondary power station, the paper puts forward the control measures on the influence of relay protection, and evaluates the risk of electric braking control system.An automatic control strategy based on security guidance and the principle of locking logic are proposed.The research results of this paper can be used as a reference for the design and transformation of electric brake of large capacity hydroelectric generator.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TV734.21

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