Overvoltage protection circuit of large power current type inverter

摘要

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overvoltage protection circuit for a large power current type inverter for preventing a spark voltage from occurring in a large power current type inverter using a thyristor (SCR) element or an overvoltage from an input power source, Resistance_One) And the transistor TR_OneThe overvoltage protection circuit is required to use a large capacity so as to withstand the overvoltage, so that it is not only difficult to design the inverter but also consumes all the voltage according to the overvoltage to heat, so that the use life is shortened. 50 of the rectifying and smoothing unit 10 and a thyristor S_One~ S₆A signal generator 60 for generating a signal to turn off the thyristor S of the commutator unit 20 when an overvoltage is generated,₇) Constitutes a pulse shed unit 70 for generating a gate pulse at a gate of the inverter circuit 20 and generates a thyristor S (S) of the commutator unit 20 when an overvoltage occurs or a spark occurs₇The gate terminal is turned on so that an overvoltage is not applied to the motor M or various control elements and a signal SIGNAL is applied to a control unit_One~ S₆) Is also turned off so that the overvoltage can be prevented originally.