A capital investment in power factor correction(STATCOM or SVC) and harmonic filtering equipment can result in a healthy return of investment –depending on the utility’s demand rate structure, production quality cost due to harmonics and voltage fluctuations in the distribution system.

ZDDQ Electric power quality correction products are part of the solution.

Most utilities charge for peak electrical demand on each month’s electrical bill. The demand charge is to allow the utilities to recoup part of their capital investment in the distribution network they operate. Each customer pays a demand charge for its peak operating load. Often inherent in the structure of these demand charges is an allowance for some inefficiency but most utilities will offer an incentive to their customers to keep electrical efficiency (measured by power factor) high. Power factor correction devices improve overall electrical efficiency upstream of their point of connection in the electrical network and can be used to minimize utility kVA demand charges.

Power electronic devices that have rapid and frequent load variations have become abundant today due to their many process control related and energy saving benefits. However, they also bring a few major drawbacks to electrical distribution systems such as harmonics and rapid change of reactive power requirements.

Harmonics may disrupt normal operation of other devices and increase operating costs. Symptoms of problematic harmonic levels include overheating of transformers, motors and cables, thermal tripping of protective devices, logic faults of digital devices and drives. Harmonics can cause vibrations and noise in electrical machines (motors, transformers, reactors). The life span of many devices can be reduced by elevated operating temperature.

Plus, rapid reactive power changes demand timely reactive power (VAR) compensation. Lack of timely and adequate VAR compensation can lead to voltage fluctuations in the electrical distribution system, impacting equipment operation, as well as product quality.

An active harmonic filter (AHF) provides an effective means to mitigate harmonics, reduce process-related voltage fluctuations and improve equipment operating life and system capacity. It can be part of a power factor correction and harmonic filtering system.

Other benefits include:

• Transformer and distribution network offloading. Improving power factor reduces kVA loading of the distribution network such that additional process equipment may be added without the need for incremental investment in transformers and distribution equipment.

• Ensuring compliance with harmonic standards. Standards limiting a customer’s harmonic pollution of the utility grid exist and can be enforced by the utility.

• Improving reliability of the distribution network and process equipment. Harmonics generated by non-linear loads can cause problems, such as logic faults of digital devices with sensitive process equipment leading to downtime and scrap.

• Reducing overheating of transformers, motors and cables to prolong the life span of these components.