SSD 605C - Supply Harmonic Analysis

11-8 Technical Specifications
605C Frequency Inverter
Supply Harmonic Analysis
Assumptions: 10000A short circuit supply capability, equivalent to 73µH supply impedance
THD
(
V
)
x 100
=
=
∑
Q
Q
h
2
1n
h40
=
h2
%
where Q
1n
is the rated rms value of the fundamental voltage of the supply transformer.
The results conform to stage 1, stage 2 and stage 3 of the Engineering Recommendation G.5/3
September 1976, Classification ‘C’: Limits for Harmonics in the UK Electricity Industry.
Drive Type 605C
Motor Power (kW) 5.5 7.5 11 15
Fundamental Voltage (V) 415 415 415 415
Typical Motor Efficiency % 88 89 91 92
Harmonic No.
RMS Current (A)
1
10.29 11.95 17.20 22.73
5
8.65 10.06 14.05 18.37
7
7.14 8.39 11.37 14.67
11
3.90 4.66 5.59 6.89
13
2.54 2.98 3.20 3.80
17
0.65 0.88 0.94 1.31
19
0.53 0.71 1.03 1.41
23
0.54 0.70 0.78 0.92
25
0.44 0.54 0.51 0.61
29
0.23 0.32 0.43 0.55
31
0.22 0.31 0.43 0.50
35
0.20 0.28 0.29 0.30
37
0.16 0.22 0.23 0.29
Total RMS Current (A) 15.9 18.64 25.83 33.72
THD (V) % 0.87 1.16 1.51 1.84