CGs for each charging type are manufactured separately to accommodate different voltage, power, and current levels. CGs are a connecting cable between EVCS and EV that transfers energy from EVCS to EV. A comprehensive understanding of the CGs available around the world is therefore required. There are a total of 11 types of connection guns worldwide (six CGs for AC and five CGs for DC). Figure 5 shows the different types of CGs that are available worldwide. Due to the different design aspects in each country for the use of CGs for the charging process, there are a total of four types of charging methods/ protocols worldwide that are currently used in the existing EVs and EVCS for the charging process.
The charging methodologies are CHArge de Move (CHAdeMO), combined charging system (CCS), Guobi ao (GB/T), and TESLA. The country of origin of these charging methodologies is from Japan, Europe, China, and the United States for CHAdeMO, CCS, GB/T, and TESLA, respectively.
Table provides the details on ratings of connector guns and their capacity.28 Type 1-AC connector plug or CG or EV plug is used for single-phase charging up to voltage level of 250 V (AC), charging current up to 32 A, and power level up to 6.6 kW.
This type of CGs was used only in the United States and Japan during early 2010 which takes 4 to 6 hours to charge the battery to 100% capacity. Type 1-AC connector is also known as SAE J1772 connector. Now Type 1-AC is replaced with new connector guns (CCS-Type 1: AC/DC) similar to the old version of Type-1 CGs but are having compatibility for AC and DC FC in a single CG.
The voltage levels are up to 250 and 1000 V for AC and DC respectively. Charging current capacity for AC and DC charging is up to 32 and 80 A, respectively. Similarly, CCS-Type 2:AC/DC CG which was proposed by German manufacturer Mennekes (Europe) that enables both single-phase and three-phase AC charging and DC charging in a single CG. The voltage levels for AC and DC charging are up to 480 and 1000 V respectively.
The current capability for AC and DC charging is 63 A (per phase) and 400 A respectively. TESLA AC/DC CGs are exclusively for Tesla EV’s having a similar configuration as CCS-Type-2 (AC/DC) but is slightly modified in terms of contact pins size which will not fit into CCS-Type 2 EV Plug.
CHAdeMO CGs are introduced in Japan initially and then spread across the globe. This type of CGs is used only for DC charging (or DCFC). There are versions of the CHAdeMO specifications viz. ver. 1.0, 1.2, 2.0, and 3.0 (future). The current version which is implemented and is in use is the CHAdeMO 2.0 specification which allows for voltage levels up to 1000 V DC and charging current levels up to 400 A (400 kW).30 China has introduced its charging standard under GB/T (China), which are GB/T AC and GB/T DC. Unlike CCS-Type 2 (AC/DC), GB/T AC/DC uses separate CGs for AC and DC charging. GB/T voltage levels for AC and DC charging are up to 480 and 950 V respectively. GB/T charging current levels for AC and DC charging is up to 32 and 250 A, respectively.
Having said about all the types of CGs available in the world and their applications in respective countries, India has its type of CGs but the specifications are mostly adopted from the specifications of GB/T AC and DC CGs. These CGs are called Bharat AC Charger AC001 and Bharat DC Charger DC001. The major difference is GB/T AC/DC and Bharat charger AC001 and DC 001 is in the voltage, power, and temperature levels. The DC voltage levels for charging the battery are limited to 48 V, 72 V, and 100 V/120 V. Power levels in AC and DC charging is limited to 10 kW (3 CGs with each of 3.3 kW) and 15/20 kW (1 CG with 15 kW or 2 CGs with each 10 kW), respectively.
The ambient temperature range of GB/T EV Plug is from 30C to +50C whereas for AC001/DC001 EV Plug has an ambient temperature range from +0C to +55C. Shortly, it is also expected by the Bharat Charger to release a new version of AC charger called AC002 which will be used to cater to a higher power like 6.6, 13, and 21 kW.
Going forward, India needs to adopt and could make it a mandatory CG in each charging station for CCS-Type 2(AC/DC) as 90% of the major manufacturers (out of 20, 12 use CCS protocol) uses CCS-Type 2(AC/DC) charging voltage up to 1000 V, current up to 400 A, and high power up to 400 kW DC power transfer using a single connector (including AC power) is possible using less space and CGs. CHAdeMO provides voltage level up to 500 V and current up to 125 A and GB/T has separate connectors for AC and DC charging which can be used only up to 250 A.