考虑火电机组深度快速变负荷能力的频率控制

风电的大规模并网和常规燃煤机组的快速爬坡能力不足对系统的频率稳定产生了严重的威胁。考虑到中国当前以燃煤机组为主的电源结构,通过合理利用火电机组深度快速变负荷能力提高机组动态特性是解决这一问题的有效手段,但是目前其在电力系统中的应用主要集中在调度上。文中提出了一种将火电机组深度快速变负荷能力应用在含风电电力系统的频率控制中的方法,该方法基于含风电电力系统的频率分析模型,首先在预测层面根据风电功率超短期预测的结果以及机组深度快速变负荷的经济性和安全性条件判断,合理制定火电机组深度快速变负荷状态的开关计划,然后利用所制定的开关计划进行实时风电功率激励下的系统频率控制,所提策略与传统自动发电控制策略紧密结合,工程上易实现。将所提方法应用于IEEE 10机39节点系统,仿真结果表明,所提方法能够有效提高含风电电力系统的频率控制能力,适用于高风电渗透率的互联电网。

Frequency Control Considering Deep and Fast Load Changing Capability of Thermal Power Units

The large-scale integration of wind power and the lack of rapid ramp-up capability of conventional coal-fired units pose a serious threat to the frequency stability of the system. Considering current power structure of China is dominated by the coal-fired units, it is an effective way to solve this problem by making rational use of the deep and fast load changing capability of thermal power units to improve the dynamic characteristic. However at present, its application in power systems mainly focuses on the dispatching. This paper presents a method to employ the deep and fast load changing capability of thermal power units to the frequency control of power systems containing wind farms. Based on the frequency analysis model of power systems containing wind farms, the method firstly makes a switching scheme for deep and fast load changing state of thermal power units according to the short-term prediction of wind power and the economic and safety conditions of the units at the prediction level. Then the system frequency control under real-time wind power excitation is operated according to the switching scheme. The proposed strategy is closely integrated with the traditional automatic generation control strategy, and is easy to implement in engineering. The simulation is done in the IEEE 10-machine 39-bus system, and the results show that the proposed method can effectively improve the frequency control capability of wind power system and can be applied to interconnected power grid with high-penetration wind power.