Gate impulse malfunction detection circuit null of electricity

摘要

PURPOSE: To surely detect anomaly of gate pulse supplying conditions to the switching elements of a power converter by verifying, with logic circuits, that gate pulses are supplied to each one phase of upper and lower arms respectively without fail, and that they are not supplied to the upper and lower arms of the same phase simultaneously. ;CONSTITUTION: The title detecting circuit has an OR circuit 10 which finds the logical sum of gate pulses supplied to the U_p-, V_p-, and W_p-phase switching elements of the upper arms of three-phase bridge connection, an OR circuit 12 which finds the logical sum of gate pulses supplied to the U_n-, V_n-and W_n- phase switching elements of the lower arms, and an exclusive OR circuit 14 which finds the exclusive OR of the output signals of the OR circuits 10 and 12. Besides, it has AND circuits 16, 18, and 20 which find the logical products of U_p and U_n, V_p and V_n, and W_p and W_n respectively, and an OR circuit 22 which finds the logical sum of the respective output signals of the AND circuits 16, 18, and 20. Consequently, it becomes possible to detect phases failing gate pulses and malfunctions of a firing phase determining circuit for the switching elements.;COPYRIGHT: (C)1993,JPO&Japio