INVERTER DEVICE

摘要

Provided is an inverter device (2) provided with a direct-current power source (4), switching elements (S) and free wheel diodes (D) which are connected to the direct-current power source (4), a means which converts direct-current voltage into predetermined alternating current-voltage, current, and frequency by turning on/off the switching elements (S), and a temperature detection unit (C) which is installed near one or more switching elements, said inverter device being provided with an estimation means (17) which estimates the temperatures of the switching element that is not provided with the temperature detection unit, and the free wheel diodes on the basis of the loss models (expressions (1)-(5)) of the switching elements (S) and the free wheel diodes (D), the thermal resistance models (expressions (6)-(9)) of modules to which the switching elements (S) and the free wheel diodes (D) are affixed, the estimated temperature increase values calculated using the loss models and thermal resistance models, and the temperature of the switching element detected by the temperature detection unit (C). On the basis of the temperature detected from one switching element, the temperatures of the other switching elements are estimated regardless of the operation mode of an inverter.