网络分析中零阻抗支路的处理

在潮流、状态估计等网络分析程序中为区分负荷类型和确定某些开关中的潮流需设置零阻抗支路。通常的处理方式是用小阻抗支路代替零阻抗支路,经验表明在大多数情况下是允许的,但在某些情况下会加大计算误差和使收敛性变坏。因此,高质量的网络分析程序对零阻抗支路需采用专门的处理算法:一是合并其两端的母线,得到状态量后再设法分开母线;二是针对零阻抗支路列出方程和状态量,加入到网络方程中一起求解。这样处理零阻抗支路,既不降低计算精度也不影响收敛性。在华北、华中和华东的160～340母线系统的潮流和状态估计的模拟计算中取得了良好的效果。

TREATMENT OF ZERO IMPEDANCE BRANCH IN NETWORK ANALYSIS

In order to define the load type and determine the power flow in some breakers, zero impedance branch is introduced in power. flow calculation and state estimation. A common approach is modeling the zero impedance branch as an impedance, small enough not to avoid affecting accuracy. Experience shows that in some cases, this may enlarge the calculation error or cause the problem of numerial ill-condition. A high quality program of network analysis needs special approaches: One is. emerging the terminal buses into a single one, then dividing it into two buses after the solution result is obtained. The other is using equality constraits to model the zero, impedance branch and the power flows in the zero impedance branch are treated indirectly as state variables. The main advantage of these two methods is the elimination of ill-condition in power flow calculation and state estimation without reducing calculation accuracy.