事故点リアクタンス演算形の保護継電方式

抄録

The theories of operation of existing relays are roughly divided into two types: one is the current differential types based on Kirchhoff's first law and the other is impedance types based on second law.
We can apply the Kirchhoff's laws to strictly formulate fault phenomena, so the circuit equations are represented non linear simultaneous equations with variables fault point k and fault resistance R_f.
This method has next two defect. 1) heavy computational burden for the iterative calculation on N-R method, 2) relay operator can not easily understand principle of numerical matrix operation.
The new protection relay principles we proposed this paper focuses on the fact that the reactance component on fault point is almost zero. Two reactance X_f(S), X_f(R) on branch both ends are calculated by operation of solving linear equations. If signs of X_f(S) and X_f(R) are not same, it can be judged that the fault point exist in the branch. This reactance X_f corresponds to difference of branch reactance between actual fault point and imaginaly fault point. And so relay engineer can to understand fault location by concept of “distance".
The simulation results using this new method indicates the highly precise estimation of fault locations compared with the inspected fault locations on operating transmission lines.