# A Review on Standardizing Electric Vehicles Community Charging Service Operator Infrastructure
## 4 Charging Type
### Conductive Charging
#### 4.1.1 Charging Mode  
* Mode 1: AC slow charging Mode 1 AC charging requires EVs to accommodate an on-board charger to enable the transfer of electricity to the battery through the passage of the current (i.e., 16 A) by converting AC to DC with the requirement of several electronic components. The on board charger consists of various converters and a transformer, i.e., a two-stage power converter along with a front-end AC-DC converter along with a DC-DC converter equipped with a high-frequency transformer [53]. Usually, on-board chargers have  
Figure 3: Taxonomy on EV charging types. Figure 2: Conductive and wireless charging for EVs. a limited power supply which restricts the charging to a certain extent due to the incurred additional cost and mass for the inbuilt electronics. Therefore, it is mainly suitable for EVs looking to make short trips with low a energy consumption of the EVs battery. [PERSON] et al. [54] designed a low-power AC single phase charger for EV. They designed the charger with an AC-DC converter and a simple buck DC-DC converter for regulating the power of the battery. Then, similarly, [PERSON] et al. [55] investigated a novel approach involving on-board AC charging for plug-in EVs consisting of an open-end winding AC motor drive along with a nine-switch converter. * Mode 2: AC moderate charging Mode 2 AC charging works similarly to Mode 1 AC charging but with a higher passage of current (32 A) and power to the EV battery. Therefore, it can charge EVs in less time than Mode 1 AC charging. Moreover, there is an additional feature of Mode 2 charging, i.e., integration of a particular type of protection cable with the standard socket equipped in the EV for charging. The standard socket provides protection to the EVs against high temperature, high current, and ground earth rise. For example, the IEC60309 charging standard operates at the current level of 32 A with the AC moderate charging in mode 2 [56]. * Mode 3: AC fast charging Mode 3 can be used for EVs charging at households or commercial CSs, which provides a higher current and a greater power passage to the EVs battery than other charging modes. It consists of EVSEs, such as charging connectors, a protection cable, etc., which needs to be installed directly into a CS. People can also deploy Mode 3 CS fast charging. Still, they need to deploy the infrastructure of high output power voltage to charge the vehicles efficiently, which can increase the overall expense of charging, thereby making it unaffordable for users [57]. [PERSON] et al. [58] designed an on-board AC fast-charging system for EVs. They mainly focused on mitigating the issue of slow charging with the integration of a full-bridge phase-shifted DC-DC converter to achieve efficient charging for EVs. * Mode 4: DC charging Mode 4 DC is mainly utilized for EVs charging at public locations such as on streets, highways, or petrol pumps where there is a need for efficient, fast charging in comparison to other modes. It is essential to integrate an AC-DC converter in the CS to charge the EVs in AC charging. However, DC charging enables direct interfacing with the battery of the EVs through the use of an off-board charger without the need for a converter. Off-boarding charging facilitates high power charging and yields high charging costs, which can discourage users from charging [56]. For example, [PERSON] et al. [59] addressed the efficiency and cost issues by introducing a dual-inverter drive in three-phase DC fast charging for EVs. They achieved improved charging efficiency corresponding to the International Electro-technical Commission standards. Then, further improving the charging efficiency, the authors in [60] designed a low-voltage EV charging technique to charge an up to 800 V battery. They considered a battery selection circuit with a DC-DC converter to outperform the conventional scheme in terms of high efficiency and low power loss. EVs can be charged at different charging levels with the help of chargers, thereby providing power in a unidirectional or bidirectional flow.