Dc offset
BSRIA Power quality guide (AG 2/2000) was written by C C Pearson and V Uthayanan and published by BSRIA in July 2000. It states:
Waveform distortion is defined as a steady state deviation from an ideal sine wave of power frequency, principally characterised by the spectral content of the deviation.
There are five primary types of waveform distortion:
- dc offset
- harmonics
- interharmonics
- notching
- noise
The presence of a dc voltage or current in an ac power system is termed dc offset. This can occur as the result of a geomagnetic disturbance or due to the effect of half-wave rectification. Incandescent light bulb life extenders, for example, may consist of diodes that reduce the rms voltage supplied to the light bulb by half-wave rectification. Direct current in alternating current networks can have a detrimental effect by biasing transformer cores so they saturate in normal operation. This causes additional heating and loss of transformer life. Dc may also cause the electrolytic erosion of earthing electrodes and other connectors.
--BSRIA
[edit] Related articles on Designing Buildings
Featured articles and news
Designing Buildings reaches 20,000 articles
We take a look back at some of the stranger contributions.
Lessons learned from other industries.
The Buildings of the Malting Industry. Book review.
Conserving places with climate resilience in mind.
Combating burnout.
The 5 elements of seiri, seiton, seiso, seiketsu and shitsuke.
Shading for housing, a design guide
A look back at embedding a new culture of shading.
The Architectural Technology Awards
The AT Awards 2025 are open for entries!
ECA Blueprint for Electrification
The 'mosaic of interconnected challenges' and how to deliver the UK’s Transition to Clean Power.
Grenfell Tower Principal Contractor Award notice
Tower repair and maintenance contractor announced as demolition contractor.
Passivhaus social homes benefit from heat pump service
Sixteen new homes designed and built to achieve Passivhaus constructed in Dumfries & Galloway.
CABE Publishes Results of 2025 Building Control Survey
Concern over lack of understanding of how roles have changed since the introduction of the BSA 2022.
British Architectural Sculpture 1851-1951
A rich heritage of decorative and figurative sculpture. Book review.
A programme to tackle the lack of diversity.