The HGL not only limits current distortion to less than 5% TDD, it also improves true power factor. Multiple package options will allow TMS customers to choose the right filter configuration for the application. Since every power system is different, harmonic mitigation requirements will differ, and even IEEE limits change based on the system loading characteristics. The HGL product returns the power of choice to the customer, allowing for different configurations to achieve different performance and monitoring results.
Minimum System Requirements
The guaranteed performance levels of this filter will be achieved when the following system conditions are met:
- Frequency: 60Hz ± 0.75Hz
- System Voltage: Nominal System Voltage (line to line) ±10%
- Balanced Line Voltage: Within 0.5%
- Background Voltage Distortion: < 0.5% THVD
Using the input current as the base, the input current waveform shall be consistent with that of a VFD with 5% AC line reactance at full load and Isc/IL<20.
Note: The presence of background voltage distortion will cause motors & other linear loads to draw harmonic currents. Additional harmonic currents may flow into the HGL filter if there is harmonic voltage distortion already on the system.
IEEE Standard 519-2014
Table 2 - Current distortion limits for systems rated 120 V through 69 kV
Maximum harmonic current distortion in percent of IL |
Individual harmonic order (odd harmonics) a, b |
ISC/IL |
3≤h<11 |
11≤h<17 |
17≤h<23 |
23≤h<35 |
35≤h≤50 |
TDD |
<20c |
4.0 |
2.0 |
1.5 |
0.6 |
0.3 |
5.0 |
20<50 |
7.0 |
3.5 |
2.5 |
1.0 |
0.5 |
8.0 |
50<100 |
10.0 |
4.5 |
4.0 |
1.5 |
0.7 |
12.0 |
100<1000 |
12.0 |
5.5 |
5.0 |
2.0 |
1.0 |
15.0 |
>1000 |
15.0 |
7.0 |
6.0 |
2.5 |
1.4 |
20.0 |
aEven harmonics are limited to 25% of the odd harmonic limits above.
bCurrent distortions that result in a dc offset, e.g., half-wave converters, are not allowed.
cAll power generation equipment is limited to these values of current distortion, regardless of actual ISC/IL.
where
ISC = maximum short-circuit current at PCC
IL = maximum demand load current (fundamental frequency component) at the PCC under normal load operating conditions.