ABSTRACT

Standby Diesel Generating Sets are commonly employed by the industry to provide reliable power to the critical process machinery. Dynamic loads such as motors, welders, elevator, crusher etc are common in several industrial applications. Most of the motors for these applications use DC Drives or VFDs in order to realize the desired efficiency or precise control. The use of these elements produces harmonic distortion in the current and voltage waveforms, as well as lagging PF. Due to the dynamic (rapid variation) condition of the loads, increased kVA demand calls for large system/generator capacity. A faster response is essential to avoid a system collapse although most of the complete kVA capacity is only used to supply the peak reactive power demands. Harmonic currents produce high frequency flux change and cause heating in generator stator cores. Rotor losses also occur because harmonic currents in the stator will induce currents in the pole faces and windings. Higher magnetic core temperatures result in a higher winding temperature resulting in premature failures and tripping. For many such applications, harmonics add a third dimension to the classic power-factor triangle, thereby increasing the apparent power required to do a particular amount of work. This requires a change the way counter measures are considered.

This case study analyzes and demonstrates a cost effective harmonic mitigation and PF correction solution for an electrical system of a cable and wire manufacturing facility utilising large capacity DG sets.

DOWNLOAD RESOURCES