1998 Volume 118 Issue 4 Pages 420-427
This paper presents the experimentally investigated results of a new type current limiter by using a model current limiter. This type of current. limiter consists of a reactor with two coils reversely winded so as to maintain the non-inductive state in the core. A parallel circuit with a power semiconductor switch and a resistor is connected to one of two coils in series. Being maintaining the non-inductive condition by the turning-on the semiconductor switch during the normal loading state, theoretically there is no voltage drop across the limiter, i.e., the impedance of the limiter holds zero. The limiter has a current limiting impedance value during the current limiting performance under a short circuit condition. The principle is that, according to turning-off the semiconductor switch broken the resistor is inserted in the circuit. resultantly the non-inductive condition is canceled. Effects of turn ratios of the reactor windings and characteristics of the inserted resistor with linear and non-linear are experimentally studied. The normal current through a semiconductor is reduced by taking high winding turn ratio of the coil connected to a semiconductor. On the other hand, the voltage across the semiconductor terminals during the current limiting period becomes large as proportion to the winding turn ratio of the coil. The current limiting impedance and energy absorptions to a nonlinear resistors during the current limiting period are numerically analyzed and compared, and the method to determine the optimum windings ratio is successfully proposed.