Other Power Quality Solutions
Flicker is a name given to frequent voltage variations caused by cyclical loads. The most troublesome aspect of flicker is usually the visible variations in output of incandescent lamps and TV screens in plants and neighboring homes.
Quality-control problems or production interruptions can also be the result of severe flicker. Flicker can be caused by arc furnaces, welders, thyristor-fed DC drives, reciprocating compressors, chipper drives, hammer mills and frequent motor starting. Available solutions to a flicker problem include alterations to operator control, var compensation, or system configurations.
SPGS engineers conduct measurements and analysis to determine cost-effective solutions to control flicker issues.
The increasingly widespread application of SCR-controlled drives in industrial processes has brought harmonic consideration into the design of electrical systems. It is common practice for industrial plants with major harmonic sources to add harmonic filters to limit voltage distortion and harmonic current flows into the utility system. On existing systems, harmonic measurements are usually made to determine the extent of voltage and current distortion and are used as a base for further calculations. If calculations show that harmonic filters are required to meet specified criteria, filters can be designed and analytically tested.
Harmonic filters must be integrated with power factor correction capacitors and must withstand any harmonics absorbed from a utility system or neighboring plant. Filters must also continue to function when loads in the plant vary or major elements such as transformers are taken out of service for maintenance. With careful planning, filters can be designed to reliably serve their intended purpose without creating new problems.
SPGS’ harmonic analysis will reveal:
- Harmonic current paths
- Amount of harmonic current flowing into the utility system
- Generated harmonic voltages
- Potential resonances
- Performance of filter and capacitor bank tuning options
- Comparison of results against the latest IEEE 519 standard