Passive harmonic filters for variable speed drives INOMAXtech
Passive harmonic filters are commonly used at the input of electric motor drive systems operated with IGBT-based variable speed drives. Its purpose is to mitigate the amount of harmonic distortion produced by the variable speed drive (VSD/VFD).
Characteristics of passive harmonic filters for variable speed drives INOMAXtech
What are harmonics in electrical networks?
Non-linear loads such as: rectificators, inverters, variable speed drives, furnaces, etc; absorb non-sinusoidal periodic currents from the network.
These currents are formed by a fundamental component of frequency 50 or 60 Hz, plus a series of superimposed currents of frequencies, multiples of the fundamental, which we call ELECTRICAL HARMONICS, which generate significant technical and economic costs.
Effects of harmonics
- The possibility of amplification of some harmonics as a consequence of series and parallel resonance.
- Reduction in the performance of energy generation, transportation and utilization systems.
- The aging of the insulation of the network components and, as a consequence, the reduction of energy.
- Distortion of electronic measurement and control elements such as instrumentation or medical equipment.
If this harmonic distortion is not addressed, it can further distort the power grid or cause damage to nearby equipment. The IEEE-519 standard establishes a voltage and current distortion limit below 5% for electrical systems.
In different industries and establishments with high usage of electronic equipment, mains voltage distortion is becoming an increasing problem. Grid voltage distortion levels have become so bad in these areas that utility providers have begun measuring the amount of distortion coming from variable speed drives.
