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Harmonic Filters (Passive)

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TMS & TCI for over 12 years the difference in service and power quality solutions for the canadian market.


Generator Compatibility of Passive Harmonic Filters



HGP 5% Passive Harmonic Filter

Limits Harmonic Distortion

  • Performance of 5% or lower THD with loads as low as 50%

  • Performance of 5% or lower THD with background voltage distortion as high as 5%

  • True 100kA SCCR

  • Meets most stringent requirements of IEEE 519

  • Generator compatible

  • Internal fusing to prevent capacitor damage

Harmonics and Power Quality

Poor power quality can be a result of variable frequency drives and other types of non-linear loads using a power conversion process that causes current and voltage distortion, known as harmonics.

Issues caused by harmonics may include:

  • Transformer and distribution equipment overheating

  • Random breaker tripping

  • Sensitive equipment failure

  • Poor power factor




The HGP Harmonic Filter, when applied at the variable frequency drive, provides a low impedance path for the major harmonic currents demanded by the drive.

This greatly reduces the amount of harmonic current flowing through the distribution system and results in improved power factor, lower RMS currents, lower harmonic current distortion, lower harmonic voltage distortion, and increased system capacity.

The HarmonicGuard Passive filter is built using the highest quality components and is the smallest package available per horsepower.

Advantages of the HGP Passive Filter

The HGP harmonic filter not only limits current distortion to less than 5% at low loads, it also:

  • Increases drive uptime

  • Eliminates nuisance tripping

  • When paired with a HGA Active filter, the results are more beneficial including higher cost savings and improved power factor

  • The UL508A configuration includes 100kA SCCR safety, fusing and easy access inside the enclosure

  • Filter bypass contactor not needed in offline VFD applications

Compared to 18-pulse drives, the HGP:

  • Is a more efficient, reliable solution at reduced loads

  • Saves money - operation cost and energy losses

  • Has a better THID at reduced loads

  • Corrects power factor in both the VFD and filter

  • Takes up less space

Meeting IEEE-519 Recommendations on Harmonics

The HGP harmonic filter provides a cost-effective solution allowing the user to meet IEEE-519 requirements. Using our harmonic analysis software, TMS can help customers meet IEEE-519. Typical applications include:

  • Wastewater treatment plants

  • Commercial buildings

  • Hospitals

  • Airports


Before HGPAfter HGP
Before HG7 After HG7


The HGP 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 HGP product returns the power of choice to the customer, allowing for different configurations to achieve different performance and monitoring results.

Performance Guarantee

Select & install the appropriate HGP Passive Harmonic Filter in a variable torque, variable frequency AC drive application, within our published technical specifications & we guarantee that the input current distortion will be less than or equal to 5% THID for standard HGP Series filters at full load, and less than 8% at 30% load. If a properly sized & installed filter fails to meet its specified THID level, TCI will provide material for necessary modifications or replacement filter at no charge.

HGP filters can also provide similar performance in other drive applications such as constant torque, DC drives & other phase controlled rectifiers, but actual THID levels can vary by load and/or speed & therefore cannot be guaranteed.

Consult TMS for assistance when applying HGP filters on these types of equipment.


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

The input VFD current waveform shall be consistent with that of a VFD with 3% AC line reactance at full load.

NOTE: The presence of background voltage distortion will cause motors & other linear loads to draw harmonic currents. Additional harmonic currents may flow into the HGP filter if there is harmonic voltage distortion already on the system. If higher levels of harmonic voltage distortion (2%-5%) are present, please use the high background distortion version of the HGP filter.

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.


ISC = maximum short-circuit current at PCC

IL = maximum demand load current (fundamental frequency component) at the PCC under normal load operating conditions.

CULUS Listed rev1










Specification sheets

HGP Resources + Manual :
Dimensions & Ratings :
Technical Papers :
Wednesday, April 25, 2018