关键词: 刚性水锤;弹性水锤;水轮机调节系统;惯性比率;数值仿真;稳定域;动态特性;

Abstract: The mathematical model for pressure water diversion system is an important tool for in-depth analysis of the dynamic characteristics of hydraulic turbine regulation system. Pressure water diversion system is usually described by rigid water hammer model or elastic water hammer model, which is depend on different consideration, and accurate model has important significance for system stability evaluation, dynamic calculation and controller optimization. In this paper, the control theory and numerical simulation were used to analyze the structure flowchart of selected turbine regulation system, then the trend of stability domain and transition regulation quality of hydropower stations with different unit inertia ratio(R1) were compared by using rigid water hammer model and elastic water hammer model. The results showed that ①When the unit inertia ratio was the same, the stability region of the elastic water hammer model was smaller than that of the rigid water hammer model, with the increasing of θr, the difference of the stability region of hydraulic turbine governing system under the two water hammer models became larger and larger. ②When the governor parameters were the same, only when R1was larger and θrwas greater than 1, there was a significant difference in system regulation quality of the two water hammer models. ③The selection of water hammer model should be judged comprehensively according to the values of R1 and θr.

Key words: rigid water hammer; elastic water hammer; hydraulic turbine governing system; unit inertia ratio; numerical simulation; stability region; dynamic characteristics