| 摘要 |
PROBLEM TO BE SOLVED: To provide an inverter controller, which does not greatly reduce an operational efficiency of a load, even if a load is increased to a large extent. SOLUTION: A frequency control section 22 gradually drops frequency of a drive signal if temperature of an inverter main circuit 5 exceeds the upper limit level, while an AC motor 6 is driven by giving the drive signal to the inverter main circuit 5 and also raises the frequency of the drive signal again, when the temperature becomes lower than the upper limit level. Moreover, under the condition that the frequency of drive signal is lowered, when temperature of the inverter main circuit 5 reaches the limit level, the drive signal is no longer output. |
