二次再热机组一次调频特性分析

Primary frequency regulation characteristics of double-reheat units

电网对火电机组的一次调频性能的要求越来越严格,而我国目前已投运的二次再热机组均存在一次调频调节品质差等问题。本文在IEEE经典模型的基础上,建立了二次再热机组一次调频模型,采用遗传算法对模型参数进行辨识,并通过测试数据分析了二次再热机组的一次调频特性,一次调频模型参数辨识结果仿真与实测曲线的对比证明了所提出模型的有效性。分析结果表明,二次再热机组设备的固有特性,使二次再热机组的一次调频性能受到极大限制,难以仅依靠控制逻辑优化实现一次调频性能显著改善。

The power grid＇s demand for performance of thermal power units＇ primary frequency regulation becomes more and more strict. However, in all the double-reheat units which has been put into service in China, poor performance of primary frequency regulation has been observed. On the basis of the IEEE classical models, a new primary frequency modulation model for double-reheat units was established, the genetic algorithm was applied to identify the model parameters and the test data were employed to analyze the primary frequency regulation performance of the double-reheat units. Comparison between the identified model simulation and the test record verifies the effectiveness of the proposed model. The results show that the inherent characteristics of the ultra-super- critical double-reheat unit limit their primary frequency regulation performance greatly, which is hard to improve only by control logic optimization.