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Inductive Charging

By Admin

10/14/2017

Inductive charging  also known as cordless charging or wireless charging. It uses an electromagnetic field to transfer energy between two objects through electromagnetic induction. It is done with a charging station. Energy is transferred through an inductive coupling to an electrical device.

                                                                                                                                                                                          NIKOLA TESLA was  the person who gave the concept of inductive charging in 1890.
Generally an induction coil is used by Induction chargers  to create an alternating electromagnetic field from within a charging base. Another induction coil in the portable device takes power from the electromagnetic field and converts it back into electric current to charge the battery. Both coils in proximity combine to form an electrical transformer. Resonant inductive coupling reduces the distances between sender and receiver coils  Recent improvements to this resonant system include using a movable transmission coil  and the use of other materials for the receiver coil made of silver plated copper or sometimes aluminium to minimize weight and decrease resistance due to the skin harmful effect.
 
Application areas
Applications of inductive charging can be divided into to two categories: 
Low power  :
High power :
 
Low power applications are generally supportive of small consumer electronic devices such as cell phones, handheld devices, some computers, and similar devices which normally charge at power levels below 100 watts.
 
High power inductive charging generally refers to inductive charging of batteries at power levels above 1 kilowatt. The most prominent application area for high power inductive charging is in support of electric vehicles, where inductive charging provides an automated and cordless alternative to plug-in charging. Power levels of these devices can range from approximately 1 kilowatt to 300 kilowatts or higher. All high power inductive charging systems use resonated primary and secondary coils.
 
BMW has revealed that the next generation 5-Series plug-in hybrid coming in 2018 will be available with a wireless charging system.
 
Advantages

Protected connections – No corrosion when the electronics are all enclosed, away from water or oxygen in the atmosphere. Less risk of electrical faults such as short circuit due to insulation failure, especially where connections are made or broken frequently.
Low infection risk – For embedded medical devices, transmission of power via a magnetic field passing through the skin avoids the infection risks associated with wires penetrating the skin.
Durability – Without the need to constantly plug and unplug the device, there is significantly less wear and tear on the socket of the device and the attaching cable.
Increased convenience and aesthetic quality – No need for cables.
 
Automated high power inductive charging of electric vehicles allows for more frequent charging events and consequential driving range extension.Inductive charging systems can be operated automatically without dependence on people to plug and unplug. This results in higher reliability. Autonomous driving technology, when applied to electric vehicles, depends on autonomous electric charging—automatic operation of inductive charging solves this problem.Inductive charging of electric vehicles at high power levels enables charging of electric vehicles while in motion (also known as dynamic charging).
 
Disadvantages
 
The following disadvantages have been noted for low power (i.e., less than 100 watts) inductive charging devices. These disadvantages may not be applicable to high power (i.e. greater than 5 kilowatts) electric vehicle inductive charging systems.
 
Slower charging – Due to the lower efficiency, devices take longer to charge when supplied power is the same amount.
More expensive – Inductive charging also requires drive electronics and coils in both device and charger, increasing the complexity and cost of manufacturing.
Inconvenience - When a mobile device is connected to a cable, it can be moved around (albeit in a limited range) and operated while charging. In most implementations of inductive charging, the mobile device must be left on a pad to charge, and thus can't be moved around or easily operated while charging.