发电机典型调速器模型结构和一次调频特性比较

Comparison of Typical Speed Governor Model with Power System Primary Frequency Characteristics

在电力系统频率特性仿真研究中,水、火常规发电机采用何种类型的调速器模型是影响仿真结果的重要因素。为此,比较了工程实际中广泛采用的传统推荐模型和现代数字电气液压式调速模型(DEH)的结构差异;并以送端电网与主网解列后频率升高的场景为例,比较了两类典型调速器模型一次调频的效果。结果表明,DEH模型因增加了PID控制、电功率反馈、多种限幅环节等的模拟,较传统推荐模型更为细致和全面;在较大幅度功率过剩条件下,水电与火电DEH模型限幅环节均导致其一次调频效果较传统推荐模型要弱,对应到实际电网中,在DEH类型调速器投入比例较高时,若大量使用传统推荐模型会产生偏乐观的结果。

In the simulation of power system frequency characteristic,it is an important factor to influence the simulation results that the type of governor is used in the conventional hydropower and thermal generator.In this paper,the structure difference between the traditional model and the modern digital electro hydraulic speed control(DEH)which are widely used in engineering practice were compared.And then taking the case of the main power grid disconnection as an example,the effect of two kinds of typical governor models on primary frequency modulation were analyzed.The results show that the DEH model is more detailed and comprehensive than the traditional model because of the simulation of PID control,electric power feedback and various amplitude limiting.Under the condition of large power surplus,the effect of the primary frequency modulation is weaker than that of the traditional model,because of the limit of the DEH model of conventional generator.Corresponding to the actual power grid simulation,when the DEH governor investment proportion is higher,the use of a large number of traditional recommended model will produce partial optimistic results.