Nowadays, the research on ice melting technology primarily focuses on the thermal effect in the steady state process of ice melting, and there is a lack of research on the transient process of ice melting devices. To solve this problem, we takes the online ice melting technology befitting for distribution network as the research object, analyzes the transient performance of ice melting from its ice melting working principle, establishes a mathematical model of the excitation inrush current transient of the grounding transformer, and proposes an excitation inrush current suppression strategy for the grounding transformer. A branch line in the mountainous area of northern Guangdong is used as a pilot line, and the transient characteristics and the feasibility of the excitation inrush current strategy are verified according to the parameters of the icing line. The results show that during the switching period of the ice melting device, the overcurrent transient state will occur in the distribution network system, which bring serious challenges and threats to the security and stability of the system. The excitation inrush current suppression strategy can better suppress the transient overcurrent and ensure the safety of online ice melting method.
In response to the significant challenges posed by strong randomness,centralized,and high-capacity integration of wind and photovoltaic power to the safe operation of the transmission network and the consumption of new energy,this paper considers the uncertainty and time correlation of wind and photovoltaic output,and proposes a distributionally robust optimization(DRO)collaborative planning method for the external transmission channels and energy storage in the transmission network with a high proportion of renewable energy.Firstly,the planning of the external transmission channels and energy storage are jointly used as decision variables and the surplus renewable energy resources are sent out through the external transmission channels.Secondly,the functions of energy storage for peak shaving,valley filling and suppressing the random fluctuations of new energy are used to promote the full consumption of renewable energy.Then,using techniques such as second-order cone convex relaxation and Taylor series expansion,the original mixed integer non-convex nonlinear programming model is transformed into a mixed integer convex programming model to achieve efficient solution.Finally,an improved IEEE 39 bus transmission system is taken as a case study to verify the validity of the proposed model and method.
电力减碳是实现国家"双碳"目标的关键环节.基于碳流分析法的电碳计量方法,能较好地反映发电、电网和用户的真实碳排放情况.然而,碳流分析法的计算量大,时间滞后,难以支撑电力低碳调度和低碳生产等.针对此,提出基于Dropout神经网络的电力系统节点碳排放因子预测方法,并在3个IEEE标准节点系统上,将该方法与传统神经网络、潮流计算进行性能对比.结果表明:该方法准确度高,计算速度快,可用于电力系统低碳调度的辅助决策依据,还可用于电力用户低碳生产和生活的引导信息.
针对当前我国光热发电适用技术标准较少、标准体系建设滞后的问题,对太阳能光热发电技术标准研究现状进行了系统梳理.结合新型电力系统清洁低碳、安全高效、智慧灵活等需求,提出面向新型电力系统的光热发电技术标准体系总体架构,并提出涵盖14个领域(基础通用、安全通用、低碳环保通用、规划设计、工程建设、设备材料、调度控制、运行检修、试验与计量、市场营销等)、若干类目与具体标准构成的体系结构.进而,针对各领域标准化现状进行分析,明确当前7个领域存在空白、5个领域不甚完善的现状,提出分阶段重点布局的4点建议.
结合大规模风电场并网分析最新技术要求,国内常用的建模方法和计算平台往往有功能上的侧重,难以同时满足故障穿越、场站功率控制、调压调频等多种要求,难以应对构建含多场控集成、准确开放的模型开发需求.对此,基于DIgSILENT/PowerFactory软件平台,利用自定义功能和DSL语言,构建"单机-场站-场控"多层级的海上风电场通用化模型.以某一实际海上风电场为例,搭建详细的风电场模型,并验证所提方案.基于现场故障穿越实测数据、现场AGC/AVC等实测数据,给出所提模型的仿真校验结果.结果表明,所提机组并网特性和场控功能与实际特性相符,模型准确有效,所建模型适用于实际工程海上风电项目的机组级和场站级控制的并网策略的开发和应用.
