14-09-2017, 03:51 PM
Wireless power transfer (WPT) wireless power transmission, or electromagnetic energy transfer is the transmission of electric power without cables. Wireless energy transmission technologies use variable electric, magnetic, or electromagnetic fields over time. Wireless transmission is useful for powering electrical devices where interconnection cables are inconvenient, dangerous or not possible.
Wireless energy techniques are mainly divided into two categories, non-radiative and radiative. In near-field or nonradiative field techniques, power is transferred by magnetic fields by inductive coupling between wire coils or by electric fields by capacitive coupling between metal electrodes. Inductive coupling is the most widely used wireless technology; its applications include the charging of portable devices such as electric telephones and toothbrushes, RFID tags and chargers for implantable medical devices such as artificial pacemakers or electric vehicles.
In far-field or radioactive techniques, also called power radiation, energy is transferred by beams of electromagnetic radiation, such as microwaves or laser beams. These techniques can transport longer distances of energy but must be directed at the receiver. The proposed applications for this type are the solar satellites and the wireless remote control airplanes. An important issue associated with all wireless energy systems is to limit the exposure of people and other living things to potentially harmful electromagnetic fields.
Wireless energy techniques are mainly divided into two categories, non-radiative and radiative. In near-field or nonradiative field techniques, power is transferred by magnetic fields by inductive coupling between wire coils or by electric fields by capacitive coupling between metal electrodes. Inductive coupling is the most widely used wireless technology; its applications include the charging of portable devices such as electric telephones and toothbrushes, RFID tags and chargers for implantable medical devices such as artificial pacemakers or electric vehicles.
In far-field or radioactive techniques, also called power radiation, energy is transferred by beams of electromagnetic radiation, such as microwaves or laser beams. These techniques can transport longer distances of energy but must be directed at the receiver. The proposed applications for this type are the solar satellites and the wireless remote control airplanes. An important issue associated with all wireless energy systems is to limit the exposure of people and other living things to potentially harmful electromagnetic fields.