| 摘要 |
PURPOSE:To quickly detect a trouble, by using a new principle based on time instead of a conventional AC theory based on single frequency. CONSTITUTION:A differentiation circuit Df and a judgement circuit Dc' are provided. The differentiation circuit receives a voltage e(t) and a current i(t) from an electric station and performs the output of the value of the voltage e(t), the current i(t) and their time-dependent partial differentiations de(t)/dt, de(t)<2>/dt<2>,..., di(t)/dt, di(t)<2>/dt<2>,.... The values of the voltage e(x, t), the current i(x, t) and their time-dependent partial differentiations (for example, e(x, t)= e(0, t)- {Ri(0, t)+L.di(0, t)/dt}x) at a place having a distance of x from the electric station are obtained by the judgement circuit Dc' from the output of the differentiation circuit Df, an inductance L, a resistance R, a capacitance C and a conductance G which are distributed constants per unit length of a power transmission line. The trouble can be detected from a first-degree equation of x obtained by the judgement circuit Dc'. An original time ralay of much higher capability than a frequency relay based on a conventional AC theory can be thus be provided. |
