Harmonic Distortion

We have extensive experience analyzing and correcting harmonic distortion problems.

Many projects we have experience with involve the application of large harmonic loads connected to relatively weak power systems. Typical applications include:

    • Ski lifts,
    • Drill rigs,
    • Oil fields,
    • Mines,
    • Airports,
    • Renewable energy,
    • Pipeline pumping plants,
    • Diesel-electric drive systems on boats,
    • Exhaust fans used to ventilate tunnels,
    • Conveyor belts,
    • Rubber mixers,
    • Heavy industrial systems.

We have experience with commercial facilities where the majority of the load consists of distributed single-phase rectifiers on three-phase distribution systems and excessive transformer heating or overloaded neutral conductors.

We can analyze sub-synchronous harmonics (i.e., harmonic distortion at frequencies below the fundamental frequency less than 50/60 Hz).

We have experience with parallel generator applications where different winding pitch-factors result in circulating zero-sequence harmonic currents leading to additional voltage distortion and winding heating or neutral overloading.

We have experience analyzing time-varying distortion on distribution systems like when an electric load is moving in the distribution system similar to an electric train going down the tracks, transferring harmonic load from one substation feeder to another, or like a large drag-line cycling through repetitive dig/swing-dump/swing operations.

IEEE Std. 519 is a guide of recommended practices that has been used in North America since the late1970's. Its current version contains recommended limits for the control of harmonic voltage and current that most electric power utilities and system design engineers have adopted as their standard guideline. We have experience in evaluating and applying Std. 519 recommendations in the analysis of harmonic data or the design of new harmonic sources.