High efficient AC drive

"The AC drive should be around 97% efficient (varies by mfr)" I put some of my observationsExample -1.We have 1800 KW Fan 690 V operated. Through transformer 6300 V are converted to 690 V. This fan when I see (on the display of the drive) shows 1270 KW. When I see this Power from the MV panel (Power going out of the transformer) is 1450 KW. so where this power goes i-e 1450 - 1270 = 180 KW.It means AC drives take 1450 KW of input power and inverters are going to out 1270 KW. Another explanation is to that whenever Air Conditioning units stop for a an hour there is significant rise in Temperature of Substation.Example -2:Same case as above a 2000 KW 690V operated motor. Drive display shows 1340 KW and Power going out of MV Panel (Siprotec Relay 7SJ series) is 1510 KW.Example -3:A 550 KW fan is driven by a AC drive. ACS800 Panel shows 180 KW and on MV panel (Siprotec Relay 7SJ series) Power was 203 KW.

Example-4:A 26KW, 400V, 50 Hz, Y, 48.7A, P.F 0.84, 1460RPM is driven through a AC drive. Drive shows 22 % of Power (5.72 KW). When we measure the Power before AC drive, current on three phases was 14.2, 14.4, 14.5. Voltage was 230 V (with respect to ground). NowInput Power to AC drive = 3 * 230 *14.4 *0.8 = 7.94 KWEfficiency = 5.72/7.94 = 71 %Although P.F is high but I am taking it 0.8
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