Page 178 - Uninterruptible Power Supplies

Rotary UPS Systems
176 Chapter Six

Input (Upstream of KS) Waveform L , L , L 3
2
1
Site: 2 MVA at ING Barings
DRANETZ PP1-8000 12:17:36 Jan-17-96

V A
O M
L A P
T A S
S

84.0 V/div 2.5 msec/div 183 A/div

OBSERVATION
> The voltage and current waveforms are almost in phase.
> Excellent power factor correction.
> The voltage and current waveforms are sinusoidal giving good
reflection onto mains.

Output (Downstream of KS) Waveform L , L , L 3
2
1
Site: 2 MVA at ING Barings
DRANETZ PP1-8000 12:03:18 Jan-17-96

V A
O M
L A A P
T S
S

81.3 V/div 2.5 msec/div 319 A/div
OBSERVATION
> The rich harmonic current load creates poor current waveform.
> However output voltage waveform from No-Break KS remains sinusoidal.
Figure 6.7 Illustration of attenuation of load waveform distortion.

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