区域电网独立运行的频率特性及稳定控制策略研究

发布时间：2018-04-05 02:31

本文选题：区域电网　切入点：独立运行　出处：《华北电力大学(北京)》2016年硕士论文

【摘要】：大电网发生严重故障造成区域电网与主网解列形成孤立电网,另一方面由于历史和经济等原因,我国仍然存在区域电网独立运行的情况。该类电网属于典型的“大机组、大负荷、小网”,单机占比重、负荷占比大,频率稳定问题是电网安全稳定最突出的难题。因此,研究孤立电网的频率动态特性及稳定控制策略,对保证孤网的稳定、安全运行具有重要意义。本文理论推导了不带和带有调频限幅的一次调频动态过程的数学表达式,进而得到最大频率偏差、最大频率变化率、静态频率偏差的数学表达式,分析了调速器静态调差系数、一次调频机组比例、发电机惯性时间常数、调速器时间常数等对一次调频的影响,分析了二次调频对区域电网频率动态过程的影响,提出了增加微分环节的二次调频优化方法。以具体的电解铝区域电网为例,针对孤网中电解铝的阳极效应问题,提出了增加加速度前馈环节的一次调频优化方法；针对企业与外网解列机组甩负荷情况,提出了自动修改负荷定值的方法。接下来,本文探讨了电解铝区域电网的稳定控制原则,提出了把故障后系统功率不平衡量控制在区域电网一次调频能力范围内的稳定控制策略,并考虑一定的裕度。提出了区域电网一次调频能力的计算方法,进而得出可切负荷量或发电量的范围。针对晶闸管整流机组的特点,提出了压负荷的控制策略。最后,本文在电力系统综合仿真程序(PSASP7.0)中建立了某电解铝区域电网模型,验证所提方法的正确性和有效性。
[Abstract]:The serious failure of large power grid results in the isolation of the regional power network from the main network. On the other hand, due to historical and economic reasons, there still exists the independent operation of the regional power network in China.This kind of power network belongs to the typical "large unit, large load, small network", the single machine occupies the proportion, the load occupies the large proportion, the frequency stability problem is the most prominent difficult problem of the power network security and stability.Therefore, it is of great significance to study the frequency dynamic characteristics and stability control strategy of isolated power network to ensure the stability and safe operation of the isolated network.In this paper, the mathematical expressions of the dynamic process of primary frequency modulation without and with frequency modulation limiting are derived theoretically, and then the mathematical expressions of the maximum frequency deviation, the maximum frequency change rate and the static frequency deviation are obtained, and the static adjustment coefficient of the governor is analyzed.The influence of the ratio of primary frequency modulation unit, the inertia time constant of generator and the time constant of governor on primary frequency modulation is analyzed. The influence of secondary frequency modulation on the frequency dynamic process of regional power network is analyzed, and the optimization method of secondary frequency modulation with increasing differential link is put forward.Taking the specific electrolytic aluminum regional power network as an example, aiming at the anode effect of electrolytic aluminum in the isolated network, the paper puts forward a method of optimizing the primary frequency modulation to increase the acceleration feedforward link, and aiming at the load rejection of the unlined units in the enterprise and the outer network,A method for automatic modification of load setting is proposed.Then, this paper discusses the stability control principle of electrolytic aluminum regional power network, and puts forward a stable control strategy to control the system power imbalance after failure within the primary frequency modulation capability of the regional power network, and considers a certain margin.The calculation method of primary frequency modulation capacity of regional power network is presented, and the range of load shedding or power generation is obtained.According to the characteristics of thyristor rectifier unit, the control strategy of voltage load is put forward.Finally, in the power system comprehensive simulation program PSASP7.0), a regional power network model of electrolytic aluminum is established to verify the correctness and effectiveness of the proposed method.
【学位授予单位】：华北电力大学(北京)
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM712

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