Electric Vehicle Charging Stations

The Electric Vehicles use batteries as a power source. These batteries need to be charged periodically to cater to the power requirements of the vehicle. Charging restores the batteries to their original state and helps them regain their stored energy. But charging an EV can be a time-consuming process. Also, the lack of charging infra is preventing the users from buying Electric Vehicles. In recent days many companies have started investing in the development of Electric Vehicle Charging Stations to help people find charging solutions for their EVs. These stations utilize some very innovative EV charging technologies for quick and efficient charging of Electric Vehicles. Although, we can plug-in our EV directly to the power socket, but using a power station considerably reduces the charging time. We can also have our personal charging stations at homes. 

Types Of Electric Vehicle Charging Stations

Electric Vehicle Charging Station also called EV charging station is an infrastructure element that supplies electricity to charge Electric or Hybrid vehicles. These stations can be public or private depending upon the ownership. The private EV charging stations are owned by individuals and are located at their residence. The public Electric Vehicle Charging Stations are owned by different companies and are located at public places like parkings, streets etc. The EV charging stations not only charge the vehicle but also monitors the battery status and the charging current parameters. It can control the current parameters in order to prevent any electric breakdown. Some of the charging stations even inform the user through a notification on their phone. There are several types of Electric Vehicle Charging Stations depending upon the methods they use to charge the vehicle. Some of these methods are popular and are being used widely at a large scale. Some are still in the development phase and need a lot of R&D to make them viable. Let us look at the EV Charging Stations and the techniques they use to charge the electric vehicles.

AC Charging Stations

AC Charging Stations utilize Alternating Current for charging the electric vehicles. AC charging is the most common method of charging EVs. These Stations serve only as the power source and use the alternating current from the power grid to charge the vehicles. The Electric Vehicles need to be plugged into charging socket which supplies the AC current from the power grid. This alternating current is then converted into DC current by the on-board charger of the vehicle. This charging process is a bit slow and takes a long course of time to complete. However, it is cheap and can be installed anywhere i.e. office, home or public charging stations. It does not put any unwanted load on the power supply grid. Depending upon the current and power supply AC charging is classified into two types: 

1. AC Level-1 Charging

This EV charging method can directly use the power supply from grids. It uses single-phase electricity to charge the Electric Vehicles. It can supply 13-20 Amp of current at 120 volts. It delivers electric power ranging from 2-4kW. They are very slow and take 8-10 hours to fully charge the battery. They can charge for a range 4-5 miles  per hours. They are generally used during nights to charge the batteries. This type of charging is only suitable for small batteries. 

2. AC Level-2 Charging

This EV charging method uses 240 volt AC current to charge the electric vehicles. It may be installed at private or public places. It can use single as well as three phase AC for charging. It can supply 32-80 Amp of current at 240 volts. It delivers electric power ranging from 8-20kW. The charging rate is 3-4 times faster that of a Level-1 AC charger. It can charge for a range 12-60 miles  per hours. This method is faster and may take 3-4 hours to completely charge a car battery. 

DC Charging Stations

DC charging stations utilize direct current for charging the electric vehicles. These Stations are being developed at a large pace in Europe and America. DC charging is also called fast charging. This method is used to charge the Electric vehicles quickly. The DC Electric Vehicle Charging Station is capable of charging an electric car within an hour. Some companies have even developed superchargers which can charge the car batteries up to 80% within half an hour. The DC charging stations can supply 80-200 amp of current at 200- 400 volts.  They can transfer a huge amount of electrical power ranging from 36-90 kW. The DC chargers are located outside of the car, hence their shape and size are not limited by the car's design. The charging stations could have large size DC chargers which can draw a huge amount of current. The DC charging setup is installed only at dedicated charging stations. They can not be installed at homes due to the huge amount of current they deal with. Tesla is developing its DC charging stations all across the US to offer its customers a super-fast charging experience.

Limitations Of DC Charging

Although the DC charging is a quite fast and convenient method of charging the Electric Vehicles, it has some limitations too. Let's discuss these limitations one by one.

1. Wastage of Power

The DC fast chargers supply a huge amount of current for charging the vehicle quickly. The supply of this large current cause wastage of electricity due to resistance of charging cables and the battery. The higher current demand puts extra load on the power grid. 

2.  Decrease Life Of Batteries

Repetitive fast charging puts load over the batteries and may decrease the battery life in the long run. The communication between the Car's battery management system and the charger is poor as the charger is located outside of the car. Due to this charging current and voltage can not be controlled effectively.

3.  Handling Complexities

The supply of a huge amount of current for fast charging generates a lot of heat that may damage the charging cable. Hence, the electric vehicle charging stations using DC fast charger needs to have very thick cables. The thick cable is very inconvenient in handling. They are heavy and do not bend easily. To solve this problem, thin DC charging cables with a cooling jacket are being used. 

Tesla's Super Charging Stations

Long charging hours is the greatest concern with Electric vehicles. Also, the availability of universal charging ports is a big problem. Tesla is trying to build a network of Electric Vehicle Charging Stations all across the globe to provide fast charging facilities to their customers.  They call it 'Superchargers'. These superchargers use high power DC current i.e. 400 volts to charge the vehicles. These chargers can charge a vehicle up to 50% within 30 minutes and up to 80% within 1 hour. Each charger has two ports and can charge two vehicles at a time. However, charging two vehicles together will divide the power between two vehicles making the charging process slower. You can also locate the supercharging station on your phone and plan your journey accordingly. You can also monitor the charging on your phone. It informs you when the car gets completely charged through a notification on your phone.

Inductive Charging Stations

          

Inductive Charging is a futuristic concept. The Inductive Charging Stations would use the phenomenon of Inductive coupling to charge the vehicles. This phenomenon is used for wireless power transmission over a short range. We all know that a current-carrying coil has a magnetic field associated with it. When another coil is placed within this range, a current is generated in the second coil. This phenomenon is called Electromagnetic Induction and is very efficient in short-range electricity transmission. The same phenomenon would be used in Inductive Charging stations to charge the electric vehicles. The floor of these charging stations would be fitted with inductive coils called the 'Primary Coils'. These coils would carry very high-frequency AC current. The Inductive charging capable cars would also have coils located at their bottom known as 'secondary coils'. When these cars would be parked at the Inductive Charging stations. The high-frequency AC current in the primary coil would induce electric current in the secondary coil of the car. This current would then be used by the on-board charger to charge the batteries. The Inductive chargers may also be installed under the road surface in areas over 0.5-1 km. This would help in charging the running vehicles without actually stopping them at charging stations. The inductive charging is a futuristic concept and is still in its development phase. When developed it would make EV charging convenient of and safe. It would also be very effective for self-driving cars which are not able to plug-in the chargers by themselves. The introduction of inductive charging on roads would decrease the stopping time at charging stations and would allow the car to have smaller batteries. However, the inductive Charging set-up would be very costly and would require high initial investments.

Battery Swapping Stations

The greatest disadvantage with an Electric Vehicle is its long charging time. Even with fast DC chargers, you need to wait for about 1 hour to fully charge the battery. To solve these problems many companies are working to develop Battery Swapping Stations and the infra related to it. These companies would sell cars without batteries to the customers. The customers would have to rent charged battery from the Battery Swapping Stations. In case the battery gets discharged, he may get it replaced by a fully charged battery again at the swapping station. This process would take just 5 minutes and the customer would get a fully charged battery. The discharged battery could then be charged at the Swapping Station.

Solar-Powered Electric Vehicle Charging Stations

Solar Power EV charging stations are being developed at large scale, all across the globe. These charging stations have solar panels mounted on their roofs. These solar panels convert the solar energy into electric energy and store in the batteries. The energy stored in the batteries or can be used to charge the Electric Vehicles. Solar charging stations would also act as parking lots and the charging cost with them would be nominal. They would decrease the reliance on the power grid for charging the electric vehicles.

Electric Vehicle Charging Stations are the  key infrastructure elements of EVs. The presence of proper charging infra can boost the EV market. Although, a lot of development is being made in the field of EV charging technologies but their pace is slow. We need to establish a network of EV charging stations all across the glob to make the Electric Mobility feasible.