互联电网有功功率平衡运行控制及其性能评价

发布时间：2018-01-16 03:23

本文关键词：互联电网有功功率平衡运行控制及其性能评价　出处：《大连理工大学》2014年博士论文　论文类型：学位论文

【摘要】：互联电网有功功率平衡运行控制中,需要控制性能评价标准来规范每个控制区域的控制行为,公平分配频率调节责任；每个控制区域要依据控制性能评价标准来设计自身的控制策略,在满足标准要求的同时尽量降低运行成本。我国目前施行的标准基于北美标准设计,但由于我国与北美电网在区域组织管理结构等方面存在差异,执行中显现出很多问题,其本质是若干理论问题悬而未解。同时,对于互联电网理论研究,准确而易用的仿真系统至关重要,而目前的仿真系统或针对暂态过程,或针对稳定状态,利用其开展有功功率平衡控制的相关研究,效率低下。针对平稳状态的评价标准,对北美和我国的评价标准及考核规则做了对比和剖析,指出北美标准存在短期控制行为评价的缺失,而我国针对短期评价所作的修改,不仅未达到预期目标,还丧失了原标准的理论完备性,失去了重要的考核合格线；由于我国在考核中加入返还机制等环节,使得标准运行机理变得十分复杂,增加了标准实施的难度。这些分析结果为后续控制策略的研究提供了理论基础。在扰动状态下的评价标准方面,提出新的标准框架,将频差值和大的负荷波动、直流闭锁等更多可能引起频率大幅度波动的事件纳入启动条件,适合我国电网频率备用水平较低、大容量机组对系统容量占比较高、大风电穿透率以及特高压交直流混联的特点,故可以有效提高电网频率的安全性。在区域控制策略的总功率调整量确定环节,基于电网频差在特定时间尺度的均值符号能够以较大的概率被预测的现象,提出了基于频差预期的AGC控制思想,并制定了相应的AGC控制策略,在大幅降低机组动作次数的同时,可保证控制区域的控制性能满足评价要求。在AGC总调节功率的分配环节,利用模型预测手段将时变的AGC机组动态特性嵌入模型中,结合连续曲线的目标追踪方式,将问题从复杂难解的非线性规划转化为二次规划问题,既简化了解算模型的复杂程度,又可实现AGC调节速率预留的“瞻前顾后”,可显著提升控制效果；依据升降趋势对AGC总调节功率曲线进行截取,可以有效地降低AGC机组间的反调,提高控制效率。针对仿真系统的研究中,基于能量守恒定律与转子旋转动能方程,提出了全新的互联电网仿真核心算法。由于利用外部特性参数对仿真模块予以描述,使得仅使用少量参数和代数方程即可构成仿真模型,此举在保证有功功率平衡研究对仿真精度要求的同时,可大幅减少模型参数的需求数量且显著地提高计算速度,适合于大型互联电网长期有功功率平衡控制及相关研究工作使用。
[Abstract]:In the control of balance of active power and power in interconnected power network, the control performance evaluation standard is needed to standardize the control behavior of each control area, and to distribute the responsibility of frequency regulation fairly. Each control area should design its own control strategy according to the control performance evaluation standard, while meeting the requirements of the standard while reducing the operating cost. The standards currently implemented in China are based on the North American standard design. However, due to the differences between China and North America in regional organization and management structure, there are many problems in the implementation, the essence of which is that a number of theoretical problems remain unsolved. At the same time, theoretical research on interconnected power grid is also given. Accurate and easy-to-use simulation system is very important, but the current simulation system is inefficient for transient process or stable state, using it to carry out relevant research on active power balance control. According to the evaluation criteria of stable state, the evaluation standards and rules in North America and China are compared and analyzed, and it is pointed out that there is a lack of short-term control behavior evaluation in North American standards. However, the modification of short-term evaluation in China has not only failed to reach the expected goal, but also lost the theoretical completeness of the original standard and lost the important qualification line. Due to the addition of return mechanism and other links in the assessment in our country, the operation mechanism of the standard becomes very complex. These results provide a theoretical basis for the further study of control strategy. In the aspect of evaluation standard under disturbance state, a new standard framework is proposed, the frequency difference and large load fluctuation are put forward. More events, such as DC locking, which may cause large frequency fluctuations, are brought into the start-up condition, which is suitable for the lower frequency reserve level of China's power grid and the higher capacity of large capacity units to the system. The characteristics of high wind power penetration rate and UHV AC / DC hybrid can effectively improve the safety of power grid frequency. In the process of determining the total power adjustment of the regional control strategy, the phenomenon that the mean symbol based on the frequency difference of the power grid in a specific time scale can be predicted with a high probability. The idea of AGC control based on frequency difference expectation is put forward, and the corresponding AGC control strategy is worked out, which can greatly reduce the number of unit movements at the same time. It can ensure that the control performance of the control area can meet the evaluation requirements. In the allocation of the total regulating power of AGC, the time-varying dynamic characteristics of AGC units are embedded in the model by the means of model prediction. Combined with the target tracing method of continuous curve, the problem is transformed from complex nonlinear programming to quadratic programming, which simplifies the complexity of the computational model. The AGC regulation rate reservation can be realized with "too many worries", which can significantly improve the control effect; According to the rising and falling trend, the total regulating power curve of AGC can be cut off, which can effectively reduce the inverse adjustment of AGC units and improve the control efficiency. Based on the law of conservation of energy and rotational kinetic energy equation of rotor, a new core algorithm of interconnected power grid simulation is proposed in this paper. The simulation module is described by using external characteristic parameters. Only a small number of parameters and algebraic equations can be used to construct the simulation model, which ensures the accuracy of active power balance research at the same time. It can greatly reduce the demand for model parameters and significantly improve the calculation speed. It is suitable for long-term active power balance control and related research work in large-scale interconnected power networks.
【学位授予单位】：大连理工大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM921.5

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