zero element

Analysis of the reason of pilot zero sequence directional protection mal-function and study of negative sequence directional element on parallel double-circuit lines

平行双回线路纵联零序方向误动原因分析及负序功率方向研究零序电哩向保护装置

When the zero sequence voltage is below the threshold, this element adopts the recorded voltage of the faulted-phase to replace the zero sequence voltage, and then determine the zero sequence power direction. The simulations use recorded fault data show that this element is correct and reliable.

当零序电压低于门槛值时，依据选相结果，该元件采用保护安装处故障前的故障相电压代替零序电压，进行零序功率方向判别。

It has a lot of characteristics, such as for any prospective current, the arc can be extinguished after the current passes through zero point at first or second time when fuse-element melts, and there is no over voltage and power loss.

它具有许多特点，如对于任何预期电流，在熔体熔化起弧后的第1次电流过零或第2次电流过零时就能灭弧，且无过电压，功率损耗小等。

The Judgment of the Element to be Zero in Calculating the Energy-Hamiltonian-Matrix in the Crystal-field Theory

晶体场理论计算能量哈密顿矩阵中为零矩阵元的判别

The bending stress is zero for the element at B.

在B处的单元体,弯曲应力为零.