| 摘要 |
PURPOSE:To obtain the title device which has high efficiency, reduces noise and oscillation and long service life by detecting a load or an oil temperature of a transformer and by driving after adding or removing in turn a revolution controlling device of each cooler according to a cooling capacity necessary to a transformer. CONSTITUTION:After a load or an oil temperature of a transformer is detected, a revolution controlling device of each cooler 4a-4c is driven through adding or removing the coolers in turn according to the detected result. For instance, in a section of a load factor of a transformer being 0-P1, the first group cooler 4a is inverter- controlled by a control characteristics A' of a phase-control angle alpha, in a section of a load factor being P1-P2, the second group cooler 4b besides the first group cooler 4a are respectively inverter-controlled by a control characteristics B' of a phase-control angle beta, and in a section of a load factor being P2-P3, the third group cooler 4c besides the first and the second group coolers 4a and 4b are respectively inverter-controlled by a control characteristics C' of a phase-control angle gamma. phase- control angles, alpha, beta and gamma of the control characteristics A', B' and C' of each controlling portion 2a, 2b and 2c are set into proper values according to a necessary cooling characteristics D of the transformer, and cooler groups are added or excepted according to a lead factor of the transformer. |
