The rapid expansion of wind power has triggered significant wind curtailment because the power system lacks flexibility to deal with the uncertainty and variability of wind power. The operational flexibility of coal-fired power plants is limited by the minimum stable firing rate in the boiler. Steam extraction and thermal energy storage could enable power output adjustment without changing the firing rate in the boiler. Thus, retrofitting existing coal-fired power plants with steam extraction and thermal energy storage is a promising option to accommodate the high penetration of wind power in the power system, especially in coal-dominated power system. This study investigated the operational flexibility of coal-fired power plants retrofitted with steam extraction and thermal energy storage. First, a linear operation model is proposed for retrofitted coal-fired power plants considering new characteristics and technical constraints. Second, a simulation framework based on stochastic unit commitment and rolling economic dispatch is developed to explore the benefits of steam extraction and thermal energy storage in wind-integrated power systems. The forecasted wind power data is used in stochastic unit commitment to evaluate start-up and shut-down cost, while real wind power data is adopted in rolling economic dispatch to calculate the actual production cost. The simulation results on the modified IEEE 24-bus system demonstrate the effectiveness of retrofitting coal-fired power plants with steam extraction and thermal energy storage for mitigating wind curtailment.

中文翻译：

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考虑储热的燃煤电厂改造灵活运行减少弃风

由于电力系统缺乏应对风电不确定性和可变性的灵活性，风电的快速扩张引发了重大的弃风限电。燃煤电厂的运行灵活性受到锅炉最低稳定燃烧率的限制。抽汽和热能储存可以在不改变锅炉燃烧率的情况下调整功率输出。因此，利用蒸汽提取和热能储存改造现有的燃煤电厂是适应风电在电力系统中的高渗透率的一个有前途的选择，特别是在以煤为主的电力系统中。这项研究调查了燃煤电厂改造后的蒸汽提取和热能储存的运行灵活性。第一的，考虑到新特性和技术约束，提出了一种用于改造燃煤电厂的线性运行模型。其次，开发了基于随机机组承诺和滚动经济调度的模拟框架，以探索风电并网发电系统中蒸汽提取和热能存储的优势。预测的风电数据用于随机机组承诺评估启停成本，而实际风电数据用于滚动经济调度计算实际生产成本。改进后的 IEEE 24 总线系统的仿真结果证明了通过蒸汽提取和热能存储改造燃煤电厂以减少弃风的有效性。