互联电网共享备用分区间分配策略研究

发布时间：2018-09-11 19:37

【摘要】：电力系统备用对于稳定系统频率及电压、提高用户供电可靠性、保障电网安全运行具有重要的作用。传统的系统备用分配方案往往基于确定性准则,例如按系统单机最大容量或系统峰荷的一定比例进行设置。然而,实际工程中采用此类确定性方法可能会使得部分地区电网备用容量不足、可靠性较差,其它地区电网则备用容量过剩、经济性较差,加之风电等新能源的不断并网也给电网的稳定运行带来了不小的冲击,因此传统的电网备用分配策略亟待改进。随着我国经济的发展,各区域间的电网互联进程也逐渐加快,不同地域的电力系统可以通过区域间联络线实现电力资源的合理分配及利用,在事故突发状态下各地区电网可以互为备用相互支援,通过区域间共享备用的设置,可以在提高系统抗风险能力的同时减少全网所需的备用总量,在一定程度上提高区域电网运行的安全性与经济性。因此在区域互联电力系统环境下,兼顾系统的可靠性和经济性,建立计及共享备用容量支持的区域互联系统备用容量分配模型,分析确定适用于互联电网环境下的系统备用容量分配策略,有着重要的理论价值与现实意义。首先,计及系统发电机组故障停运、负荷预测偏差及风电机组出力偏差等随机因素对系统运行产生的影响,考虑系统的稳定性约束条件,基于系统可靠性机会约束建立了单区域系统的备用容量分配模型,模型分别在两种不同情境下考虑了备用分配方案对系统备用成本、系统频率偏差及系统停电损失产生的影响,并提出了基于改进快速排序技术的变异粒子群算法对其进行求解,以改善模型的求解速度和优化结果的性能;其次,计及区域电网范围内不同子系统的备用需求特点,将区域电网的类型划分为三类,基于单区域系统的研究分析,建立了考虑系统可靠性机会约束的区域互联系统的备用容量分配模型,模型量化了共享备用在区域联络线间的具体调用过程,采用基于改进快速排序技术的变异粒子群算法进行求解;最后,以IEEE标准测试系统为例,对本文提出的系统备用容量分配模型及求解算法进行了分析验证,考虑不同优化目标的影响,分别得出了单区域系统及区域互联系统的备用容量分配方案,同时分析了可靠性安全约束、系统负荷量变化及风电并网对系统备用分配结果产生的影响,并针对系统模型中的关键参数进行了敏感度分析。结果表明,与实际电网运行中选用的备用确定性方案比较,采用本文备用容量优化策略在保证系统可靠运行的前提下降低了系统所需的备用容量及成本,区域互联系统相较单区域系统有效地提高了系统的可靠性与经济性,为电力系统备用容量分配策略研究提供了新的思路。
[Abstract]:Power system reserve plays an important role in stabilizing the system frequency and voltage, improving the reliability of power supply, and ensuring the safe operation of power grid. The traditional system standby allocation scheme is usually based on deterministic criteria, such as the maximum capacity of a single machine or a certain proportion of the peak load of the system. However, using this kind of deterministic method in practical engineering may lead to insufficient reserve capacity and poor reliability in some areas, while in other areas, the reserve capacity in other areas is excessive and economical. In addition, the continuous grid connection of new energy sources such as wind power also has a great impact on the stable operation of the power network, so the traditional standby allocation strategy of the power network needs to be improved urgently. With the development of our country's economy, the process of power grid interconnection among different regions is also speeding up gradually. The power system in different regions can realize the rational distribution and utilization of power resources through inter-regional liaison lines. In the emergency state, the regional power network can support each other for each other. By sharing the reserve among the regions, the system can improve the system's ability to resist risks and reduce the total amount of reserve needed by the whole network at the same time. To a certain extent, improve the security and economy of regional power grid operation. Therefore, in the regional interconnected power system environment, taking into account the reliability and economy of the system, a reserve capacity allocation model of the regional interconnected power system considering and sharing backup capacity support is established. It is of great theoretical value and practical significance to analyze and determine the system reserve capacity allocation strategy suitable for the interconnected power network environment. First of all, considering the influence of random factors, such as failure outage, load forecasting deviation and wind turbine output deviation, on the system operation, the stability constraints of the system are considered. Based on the system reliability chance constraint, a reserve capacity allocation model for a single area system is established. The model considers the effects of the standby allocation scheme on the system standby cost, system frequency deviation and system blackout loss in two different scenarios. In order to improve the solution speed of the model and the performance of the optimization results, a modified fast sorting algorithm based on mutation particle swarm optimization algorithm is proposed to solve the problem. Secondly, considering the characteristics of standby requirements of different subsystems in the regional power network, The type of regional power network is divided into three categories. Based on the research and analysis of single area system, the spare capacity allocation model of regional interconnected system considering system reliability opportunity constraint is established. The model quantifies the specific call process of shared standby between the regional tie-lines, and uses the modified fast sorting algorithm to solve the problem. Finally, the IEEE standard test system is taken as an example. This paper analyzes and verifies the system reserve capacity allocation model and its solution algorithm. Considering the influence of different optimization objectives, the reserve capacity allocation schemes of single area system and regional interconnected system are obtained respectively. At the same time, the effects of reliability and safety constraints, system load variation and wind power grid connection on the system reserve allocation results are analyzed, and the sensitivity of the key parameters in the system model is analyzed. The results show that the reserve capacity optimization strategy is adopted to reduce the reserve capacity and the cost of the system on the premise of ensuring the reliable operation of the system, compared with the backup deterministic scheme used in the actual power network operation. Compared with single area system, regional interconnected system improves the reliability and economy of the system effectively, and provides a new idea for the research of reserve capacity allocation strategy in power system.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM732

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