核电机组动态模型及涉网保护协调优化的研究

发布时间：2018-05-13 07:51

本文选题：压水堆核电机组 + 动态模型　；参考：《武汉大学》2014年博士论文

【摘要】：目前,我国核电发展迅速,核电具有单机容量达到百万千瓦级别、核安全要求高、运行成本低等特点,其功率输出特性、频率调节特性等均异于常规的水、火电机组,且核电机组及其辅助设备对电网频率、电压扰动敏感,大容量的核电机组接入电网后若突然跳闸,将导致电网瞬间失去较大的有功电源,对电网安全稳定运行造成冲击。因此,对大型压水堆核电机组动态模型及涉网保护协调优化相关问题进行研究具有重要的理论价值和实际应用意义。本文在查阅了大量国内外文献资料的基础上,结合多项实际科研课题,对大型压水堆核电机组接入电网的动态模型及涉网保护协调优化相关问题进行了系统深入的研究。论文的主要研究内容如下：对大型压水核电机组的组成和运行特性进行分析,对核电机组接入电网的模型及建模方法／思路进行了归纳、总结并进行了进一步深入研究。针对第三代核电机组AP1000特点,建立大型压水堆核电机组反应堆及其热力系统模型,该模型由堆芯系统模型、一回路冷却剂系统模型和二回路蒸汽系统模型组成。基于整形熵理论分析反应堆及其热力系统的自稳定性,并进行了仿真算例验证。提出了一种改进的教学互动(IETLBO)优化算法,将该算法应用于核电机组反应堆功率控制系统模型参数辨识中,结果表明IETLBO算法收敛速度较快,具有更高的辨识精度和鲁棒性,可有效辨识反应堆功率控制系统的模型参数。基于PSASP/UPI建立了核电机组接入电网动态模型,并实现了核电机组模型与电网模型的联合仿真计算。所建立的核电机组动态模型由反应堆及其热力系统模型、调速系统模型、励磁系统模型和相关保护系统模型组成。与核电专用仿真软件PCTRAN对比验证了所建立核电机组动态模型的有效性,但本文建立模型克服了PCTRAN不能应用于电力系统仿真的缺陷。仿真分析了核电机组的功率调节特性,结果表明在电力系统仿真计算中应考虑核汽轮机主蒸汽压力特性。基于所建立的核电机组动态模型,在大电网实际算例中仿真计算了核电机组的一次调频特性,采用暂态能量函数的稳定裕度分析方法评价了核电机组的一次调频参数对电网稳定性的影响,并提出了核电机组一次调频参数优化方案；仿真计算了核电机组超速保护和超加速度保护特性,计算结果也验证了所建立的机组超速保护和超加速度保护模型的有效性。建立了核电机组的失磁保护数学模型,基于大型压水堆核电机组动态模型和超速保护／超加速度保护模型,仿真分析了满载运行和低功率运行工况下核电机组失磁动态特性和机理。结果表明,核电机组满载失磁对反应堆及其热力系统冲击大,失磁保护应可靠动作,减小对电网和机组的冲击；低功率运行时,失磁故障对反应堆及其热力系统冲击有限,核电机组可以保持短时异步运行,以减小核电机组跳闸对电网和机组的冲击,仿真结果表明,通过设置频率死区可以避免超加速度保护引起的机组超速问题。
[Abstract]:At present , the development of nuclear power in China is rapid , the nuclear power has the characteristics of a single - machine capacity of a million - kilowatt level , high nuclear safety requirement , low operation cost and the like , and the power output characteristic and the frequency regulation characteristic of the nuclear power unit are different from the conventional water and thermal power unit .

On the basis of consulting a large number of domestic and foreign literatures , this paper systematically studies the dynamic model of the power grid of large - scale PWR nuclear power unit and the related problems of network protection coordination optimization . The main research contents are as follows :

Based on the analysis of the composition and operating characteristics of the large - scale PWR nuclear power unit , the model and the modeling method / train of the nuclear power unit ' s access network are summarized and further studied . According to the AP1000 characteristics of the third generation nuclear power unit , a large - scale PWR nuclear power unit reactor and its thermal system model are established . Based on the shaping entropy theory , the self - stability of the reactor and its thermal system is established . The proposed algorithm is applied to the model parameter identification of the nuclear power plant reactor power control system . The results show that the IETlbo algorithm has a faster convergence speed and higher identification accuracy and robustness , and can effectively identify the model parameters of the reactor power control system .

The dynamic model of nuclear power unit is established based on PSASP / UPI , and the simulation calculation of nuclear power unit model and grid model is realized . The dynamic model of nuclear power unit is composed of reactor and its thermal system model , speed regulation system model , excitation system model and related protection system model .

Based on the established dynamic model of the nuclear power unit , the primary frequency modulation characteristic of the nuclear power unit is simulated in the practical example of the large power grid , and the influence of the primary frequency modulation parameter on the stability of the power grid is evaluated by using the stability margin analysis method of the transient energy function , and the optimization scheme of the primary frequency modulation parameter of the nuclear power unit is proposed ;
The overspeed protection and the ultra - acceleration protection characteristics of the nuclear power unit are simulated . The results of the simulation show that the overspeed protection and the super - acceleration protection model of the unit are valid .

Based on the dynamic model and the overspeed protection / super acceleration protection model of the nuclear power unit , the dynamic characteristics and mechanism of the loss of the nuclear power unit under full load operation and low power operation are simulated and analyzed . The results show that the full load loss of the nuclear power unit has great impact on the reactor and its thermal system , and the loss of magnetic protection should be operated reliably to reduce the impact on the power grid and the unit .
At low power operation , the power loss fault has limited impact on the reactor and its thermal system , and the nuclear power unit can keep the short - time asynchronous operation to reduce the impact of the trip of the nuclear power unit on the power grid and the unit , and the simulation results show that the overspeed problem caused by the ultra - acceleration protection can be avoided by setting the frequency dead zone .

【学位授予单位】：武汉大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM623

【相似文献】