JPS5642323A - Capacitor type potential transformer - Google Patents

Abstract

PURPOSE:To suppress the secondary short-circuit current and to prevent occurrence of magnetic resonance by a method wherein a series circuit of a discharging gap and nonlinear resistor and a capacitor are connected in parallel between an intermediate tap on the primary side of a leakage transformer and an earth terminal. CONSTITUTION:The main terminal U1 of an auxiliary leakage transformer Trl is connected at the connected point of a high-tension capacitor C, and a voltage dividing capacitor C2 and an earth terminal V is directly grounded together with the earth terminal of the capacitor C2. And a tap U2 is led out from almost the center part of the primary winding of the transformer Trl and the capacitor CG and the series circuit of the nonlinear resistor RNG and the gap G are connected between the tap U2 and the terminal V respectively. In such a circuit constitution as above-mentioned, the gap G does not discharge at a lightning impulse, the gap discharges at an overvoltage of the secondary short-circuit, thereby suppressing both secondary short-circuit current and an overvoltage. Besides, a flow of current is easily broken by the resistor RNG and the gap G when the secondary short-circuit is opened and magnetic resonance can be suppressed.