摘要
为了解决多端柔性直流系统（VSC-MTDC）直流电压越限和功率分配不合理的问题,提出了一种与调度系统相结合的协调控制策略。通过调度系统进行短期负荷预测,并以所有下垂控制站的下垂系数、直流电压参考值和直流功率参考值为决策变量,以直流电压、直流功率和直流线路电流不越限为不等式约束,建立系统损耗和直流电压偏差最小为目标的多目标优化模型。此外,为了保证系统稳定性,通过建立反映VSC-MTDC直流侧响应的状态空间模型的方法,引入所有下垂系数之和为常数的等式约束。算例中搭建了四端VSC-MTDC系统,对定功率站的功率不变、功率突变以及计划停运等情形进行实验。结果表明,所提算法能在保证系统稳定的前提下,确保各节点直流电压波动范围为额定值的–5%~5%以内,同时保证各站的直流功率不满载。因此,所提算法能够优化VSC-MTDC的运行特性,可作为一种稳态调控或计划停运的控制手段。
To solve the problem of overloaded DC voltage and power inappropriate allocation in VSC-MTDC transmission system, we proposed a coordinated control strategy combined with the scheduling system. The short-term load forecasting is carried out by the scheduling system, and the droop coefficients, DC voltage reference values and DC power reference values of all droop-control stations are considered as decision variables, while the DC voltages, DC powers and DC line currents are not limited as inequality constraints, so that a multi-target optimization model for the minimum system loss and the minimum DC voltage deviation is established. In addition, in order to ensure the stability of the system, with an established state space model reflecting the response of the VSC-MTDC DC side, the equality constraint of the sum of all droop coefficients as a constant value is introduced. In the example, a four-terminal VSC-MTDC system is built to be tested under the cases of the power invariance, power mutation and planned outage of the fixed power station. The results show that the proposed algorithm can ensure that the DC voltage of each node is between –5% and 5% of the rated value, ensuring that the DC power of each station is not full, on the premise of ensuring the stability of the system. Therefore, the proposed algorithm can optimize the operation characteristics of VSC-MTDC, and can be used as a control means for steady state control or planned outage.
作者
郭敬梅
余超耘
黄辉
GUO Jingmei;YU Chaoyun;HUANG Hui(Electric Power Research Institute of Guangdong Power Grid Corporation,Guangzhou 510080,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2018年第7期2181-2188,共8页
High Voltage Engineering
基金
中国博士后科学基金面上项目(2016M602436)~~
