考虑控制模式影响的多电压等级直流电网潮流计算方法

多电压等级直流电网可满足不同地区接入各类能源和负荷的电压等级需求,是未来电网建设的发展方向。直流电网潮流分析是电网规划设计、运行控制的基础,而相比于传统电网潮流分析,多电压等级直流电网控制方式灵活、运行方式多样,使得潮流分析更加复杂。计及换流站的控制方式,首先,对多电压等级直流电网进行分区处理,建立了多电压等级直流电网稳态等值模型;然后,基于牛顿迭代法建立节点导纳矩阵及潮流方程,推导了直流电网潮流计算方法;最后,基于PSCAD搭建了多端直流电网模型,验证了所提计算方法的有效性和正确性。

Calculation Method for Power Flow of DC Power Grid with Multi-voltage Levels Considering Influence of Control Modes

The DC power grid with multi-voltage levels can meet the requirements of voltage level in different regions to connect to various energy sources and loads. It is the development direction of future power grid construction. Power flow analysis of DC power grid is the basis of grid planning, design and operation control. Compared with traditional power flow analysis, power flow analysis of DC power grid with multi-voltage levels is more complicated due to its flexible control methods and diverse operation modes. Taking into account the control modes of converter station, firstly, the DC power grid with multi-voltage levels is partitioned, and the steady-state equivalent model for DC power grid with multi-voltage levels is established. Then, the node admittance matrix and power flow equation are established based on Newton iterative method, and the power flow calculation method of DC power grid is derived. Finally, a multi-terminal DC grid model is built based on PSCAD, which verifies the validity and correctness of the proposed calculation method.