摘要
随着直流源储荷的接入与柔性直流电力电子设备的发展,含多种分布式电源(distributed generation,DG)的交直流混联电网被认为是未来电网的主流架构,这给系统操作带来了更多灵活性,但也加剧了量测数据不足的问题,使得系统状态估计求解更加困难。目前成熟的交流状态估计未计及直流系统状态量和量测量的特征及各类DG出力的不确定性,且通常默认换流器控制方式已知,控制方法未知时的伪量测建模技术有待研究。采用计及电压源换流器(voltage source converter,VSC)损耗的模型,对可观型VSC和不可观型VSC分别采用基于控制信息和基于高斯混合模型(Gaussian mixture model,GMM)的伪量测建模方法,在加权最小二乘法(weighted least squares,WLS)的基础上,提出一种改进的交直流混联电网状态估计算法。在经过修改的IEEE-14节点系统中进行大量仿真计算分析,结果表明所提算法不依赖于量测配置和调度中心与VSC间的通信过程,伪量测数据动态描述能力优于6次采样扩展卡尔曼滤波算法(extend Kalman filter,EKF),具有良好的实用性和抗差性,未来可扩展到电力电子化电力系统状态估计中使用。
With the integration of DC sources/storages/loads and the development of flexible DC power electronic devices,hybrid AC/DC networks with various distributed power generations(DGs)are considered to be the mainstream architecture of future networks,which brings the system operation more flexibility,and also increases the difficulty of system state estimation with aggravating the problem of insufficient measurement data.At present,the mature AC state estimation does not consider the characteristics of the DC system state variables/measurements and the uncertainty of various DG outputs.Besides,it is generally assumed that the control mode of the converter is known.Therefore,it calls for the pseudo measurement modeling method when the control method is unknown.In this paper,the voltage source converter(VSC)model considering the loss is used for pseudo measurement modeling of converters:the control information-based for the observable VSCs and the Gaussian mixture model(GMM)-based for the unobservable VSCs.Based on weighted least squares(WLS),an improved AC/DC hybrid grid state estimation algorithm is proposed.A large number of simulation calculations are carried out in the modified IEEE-14 bus system.The results show that the proposed algorithm does not depend on the measurement configurations and communication between the scheduling center and VSCs.The dynamic description capability of pseudo measurement data is better than the 6-sample extend Kalman filter(EKF).The results show it is of good applicability and robustness.It can be extended to power system state estimation with complex power electronic devices in the future.
作者
李幸芝
韩蓓
李国杰
汪可友
徐晋
LI Xingzhi;HAN Bei;LI Guojie;WANG Keyou;XU Jin(Key Laboratory of Control of Power Transmission and Conversion,Ministry of Education Shanghai Jiao Tong University,Minhang District,Shanghai 200240,China)
出处
《全球能源互联网》
CSCD
2022年第3期271-281,共11页
Journal of Global Energy Interconnection
基金
国家自然科学基金项目(52107113,51877133)
国家重点研发计划(SQ2021YFE012158)。
关键词
换流器伪量测
交直流混联电网
状态估计
分布式电源
高斯混合模型
pseudo measurement modeling of converters
hybrid AC/DC networks
state estimation
distributed generation
Gaussian mixture model
