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Conducted emissions are the effects in power quality that occur via electrical and magnetic coupling, electronic switch of semiconductor devices, which form a part of electromagnetic compatibility issues in electrical engineering. These affect the ability of all interconnected system devices in the electromagnetic environment, by restricting or limiting their intentional generation, propagation and reception of electromagnetic energy.
Conducted emissions consist a part of electromagnetic interference in circuits that mainly create issues in delivered power quality, owing to interference caused by harmonics arising due to linear & non linear loads present in the electric system mainly due to increasing presence of switched mode power supply and other consumer electronics. Due to these aggregated interferences, the delivered electric power quality from the mains electricity system affects the performance of electrical home appliances. These could include a decrease in lumen output of bulbs, flicker and poor heating of induction coil in kettles, and heating elements of other home appliances in every-day use.
Following the effects of conducted emissions, the electric power quality is classified separately in common AC mains and DC mains systems. Since alternating current technology has been well established, the parameters and the effects in power quality in AC are well established. The parameter for measuring AC power quality is called is termed total harmonic distortion , and it measures the power quality of power supply for different voltage levels. Due to the recent developments in DC technology, the interconnections between DC and AC mains give rise to harmonic issues not previously experienced. Especially, the effects in DC power quality due to conducted emissions are not well understood. Moreover, the interconnections of AC and DC mains has given rise to further electromagnetic interference issues not previously known. Based on the current EMC standards, conducted emissions are measured from 150 kHz and 30 MHz, however there exists a gap in the electric power quality measured up to 2 kHz and the conducted emissions in the low frequency up to 150 kHz. The gap frequency range is termed Supraharmonics.
Further, following the advancements in telecommunications engineering, the presence of electronic devices has gradually increased in the AC mains grid network towards having more semiconductor based switch devices, giving rise to further electromagnetic interference issues due to conducted emissions in the near and far electromagnetic environment. The electric grid progresses towards becoming increasingly nonlinear system and newer issues in power quality are being addressed.