智能软开关(soft normally open point,SNOP)是一种代替传统联络开关可进行实时功率控制的电力电子装置,在正常运行时主要提供有功功率的传输,当电压问题突出时,SNOP可进行电压无功控制。为此,首先建立了SNOP电压无功控制问题的时序模型,该模型数学上属于大规模非线性规划问题,给计算求解带来较大的挑战;通过采用凸松弛技术将其转化为二阶锥模型,实现该问题的快速、准确求解;最后,采用IEEE 33节点算例,对所提出的优化模型与求解方法进行了分析与验证。结果表明,利用SNOP在有源配电网中进行电压无功控制,可以有效地缓解电压波动、降低系统损耗;基于二阶锥规划的求解方法在保证求解最优性的同时,极大地提高了计算效率。
This paper proposes a new method for the planning of stand-alone microgrids.By means of clustering techniques,possible operating scenarios are obtained considering the daily patterns of wind and load profiles.Then,an approximate analytical model for reliability evaluation of battery energy storage system is developed in terms of the diverse scenarios,along with multistate models for wind energy system and diesel generating system.An optimal planning model is further illustrated based on the scenarios and the reliability models,with the objective of minimizing the present values of the costs occurring within the project lifetime,and with the constraints of system operation and reliability.Finally,a typical stand-alone microgrid is studied to verify the efficiency of the proposed method.
