Harmonic Solutions Marine provides a range of PQ services and conducted EMI services to the marine sector worldwide.

We offer a complete range of audits, investigations, consulting services and compliance testing against classification society rules on harmonic voltage distortion (THDu) including IACS UR E24 Rev 1 (requirements for vessels with electric propulsion and passive harmonic filters).


Marine PQ Services –  providing marine power quality and conducted EMI services worldwide…

Harmonic Solutions Marine, a division of Sentinel Power Quality Group FZE, based in the United Arab Emirates, are specialists in marine harmonics, power quality and conducted EMI and also have PQ engineers based in the UK and elsewhere.

Cable ship - Continual soft starter card failures on azimuth main propulsion system
Investigations into regular thruster VFD failures on heavy lift crane ship

HSM PQ engineers can mobilise rapidly….

Cycle by cycle PQ monitoring on cruise vessel with full electric propulsion
PQ audits, harmonic compliance checks and investigations on cruise liners

Marine PQ services include :

  • Harmonics, power quality and conducted EMI audits including UR E24 compliance
  • PQ and conducted EMI investigations into marine equipment malfunction/failure
  • Diagnosis and monitoring of common mode voltage and current (due to VFDs) and other EMC issues
  • Studies (including harmonic modelling) on harmonics and related topics for marine power systems
  • Consulting services regarding all aspects of marine PQ

Advanced harmonics, PQ and conducted EMI measuring equipment

For investigations, Harmonic Solutions Marine utilise advanced, cycle by cycle PQ recorders which capture every single cycle, harmonics to 512th (voltage) and 256th (current), capture every PQ event and record over 5000 power and PQ parameters automatically. The data captured is then analysed by powerful investigative software.

Samples of marine PQ measurements :

AC Current measurement to 25kHz

Common mode and other EMI measurements

For higher frequency measurements 200MHz/500MHz digital storage oscilloscopes with spectrum analyser capability are utilised for SCR drive line notching, voltage spikes, VFD output and common mode voltage/current monitoring.

Thruster VFD failure investigations on diving support vessel
Monitoring of AFE 1600kW azimuth main propulsion VFD for conducted EMI
Output measurements on 1700kW VFD on seawater pump application

For medium voltage power systems dedicated VTs and CTs are used. For common mode and other EMI measurements, portable EMC spectrum analysers (1Hz to 30MHz) are also used together with differential adaptors and attenuation units for conducted common mode voltage and current measurements, near field probe kits and antennas for radiated emissions and sophisticated software to facilitate detailed reporting.

Some sample measurements :

DP3 offshore/subsea construction vessel. Investigation in propulsion motor failures

Dedicated Marine PQ Engineers

Harmonic Solutions Marine PQ engineers are fully qualified electrical engineers to PhD level with extensive experience in marine harmonics, power quality and conducted EMI.  All PQ engineers have considerable knowledge in other associated electrical disciplines including variable speed drives (AC and DC), generators, motors and other equipment.

All engineers have valid medical certificates. For applicable countries, Yellow Fever and AIDs (negative) certificates and Police Reports from countries of residence are available. Negative COVID-19 test certificates and vaccine passports, when applicable, can be provided.

Sample of marine customers:

  • V Ships
  • Carnival UK Group
  • Anglo Eastern
  • Gennel Engineering
  • Caterpillar Propulsion
  • Fraser Nash
  • Babcock Technology
  • Marine Accident Investigation Branch
  • Bakker Sliedrecht
  • CTC Marine
  • E-Marine
  • Addax Petroleum
  • American Bureau of Shipping
  • Parkburn Mechanical Handling
  • Mermaid Maritime
  • Algonet

For more information on common marine PQ problems click here.

Please contact Harmonic Solutions Marine if you require our specialist services by clicking here.

For information on Harmonic Marine range of marine products and services please click on the appropriate link below :

MOSAF Active Filter

Series Passive Harmonic Filters

du/dt Chokes & Sinewave Filters

Marine power quality monitoring

TVSS – Sinetamer