| 摘要 |
PROBLEM TO BE SOLVED: To reduce the absolute value of a junction temperature by calculating the switching loss when a semiconductor power element in an inverter device is switched, and calculating the on-loss when the semiconductor power element is turned on and a constant current flows. SOLUTION: This elevator control device is provided with a switching loss arithmetic unit 20 momentarily receiving the voltage command signal of a comparator 9, the output current signal of a current detector 13, and a proximate polynominal and add-calculating the switching loss of a power element. The elevator control device is also provided with an on-loss arithmetic unit 21 calculating the momentary on-loss based on the voltage command signal, the output current signal, and the proximate polynominal like the switching loss calculation when a semiconductor element such as IGBT is turned on and a current flows in a transistor. Even when a low-frequency large current flows, the momentary IGBT loss and a junction temperature rise are calculated, it is momentarily calculated that the temperature of a chip in the IGBT becomes the guaranteed maximum temperature, and a control current is lowered to prevent the temperature rise. |
