Patent ID: 8564913

Claim:
A driving device for a semiconductor element for individually driving a semiconductor element composing a power conversion apparatus, the driving device comprising: a plurality of protection circuits that detect information necessary for performing protection operation for the semiconductor element; a pulse signal generation circuit that sets pulse sequence signals with a pulse width differently for each of the plurality of protection circuits, and outputs a pulse sequence signal corresponding to the protection circuit that has been first detected a need for protection operation delivering continuously in a time period of the detection of a need for protection operation; an alarm signal forming circuit that forms an alarm signal by ON-OFF control of a switching element included in the alarm signal forming circuit and externally outputs the alarm signal; a protection operation state discrimination circuit that discriminates existence of a protection operation state based on the alarm signal from the alarm signal forming circuit and outputs a protection operation discrimination signal; and an alarm control circuit that delivers the pulse sequence signal outputted from the pulse signal generation circuit to a control terminal of the switching element in the alarm signal forming circuit based on the discrimination by the protection operation state discrimination circuit.