| 摘要 |
PROBLEM TO BE SOLVED: To ensure redundancy of the whole system not only for failure in an inverter, but also for failure in a motor fan. SOLUTION: In the case of the failure in the motor fan 16b which applies forced draft to a CVCF inverter 9', a circuit element of an inverter converting part cannot be cooled, so that the inverter which performs forced draft with the motor fan 16b is required to be disconnected. The CVCF inverter and a plurality of groups of VVVF inverters 4a' are disconnected from the system and the VVVF inverter 4b' is switched to the CVCF inverter so as to be driven. At that time, the VVVF inverters 4b' to be switched is arranged so as to be forcibly blown from another motor fan 16a, thereby ensuring redundancy for failure in the motor fan 16b. |
