| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that in an inverter circuit having a plurality of switching elements parallely connected, the parallely connected switching elements are switched but current detection resistances are not switched, which makes it difficult to detect accurately currents ranging from small currents having several A to large currents having several hundreds A.SOLUTION: The inverter device comprises: a drive circuit 10 in which a plurality of switching element groups 101 and 102 having an upper arm-side switching element Qe and a lower arm-side switching element Qs as a pair are parallely connected and current detection resistances 103 and 104 are serially connected to the lower arm-side switching elements respectively; and driving control means 20 that controls switching elements of the drive circuit. The driving control means, by switching the switching element groups parallely connected depending on currents to be detected, detects the currents using one current detection resistance 103 when the currents are small so as to increase current detection accuracy, and divides the currents by a plurality of current detection resistances 103 and 104 when the currents are large to suppress a current capacity and heat generation per one switching element. |
