Dc Charging Of Electric Vehicle/Charging Type

 

                   Types of DC Charging Of  Electric Vehicle

In this post, I am going to talk about DC charging or DC charging of electric vehicles.

          in this we are going to learn about three things.

 

1. What are the main parts of a DC charger

2. What kinds of connectors are used for DC charging and

3. Third, what are the limitations of DC

 

1. let's see what are the main parts of a DC charger. DC fast chargers typically operate at level three charging powers and are designed to quickly charge electrical vectors with electrical power between 50 kW and 350 kW at higher power.

                      The AC to DC converter the DC to DC converter and the power control circuits are getting bigger and more expensive, which is why the DC fast charger is implemented as all forced chargers instead of own purchased chargers so it does not take up space in the vehicle and fast charger can be shared by many users. Now let's analyze the power supply for DC charging from the DC charger to the electric vehicle battery.

             In the first step, the AC or AC power supplied by the AC grid is first converted to DC or DC using a rectifier in the DC charging station, then the power control unit appropriately adjusts the voltage and current of a DC converter to convert the variable DC power supplied to charge the battery, there are safety interlocks and protection circuits used to de-energize the AV connector and stop the charging process.

        When there is a malfunction or incorrect connection between the EV and the charger, the battery management system or BMS plays the key role in communicating between the charging station and in controlling the voltage and current supplied to the battery and in protection circuit. in case of an unsafe situation

          for example, control area Network briefly refers to a scan or streamline communication, called PLC for short, is used for communication between the e V and charger now that you have a basic idea of ​​how a DC charger is configured.

DC charger connectors

Five types of DC charging connectors used worldwide

 

 

1.  CCS or the combined charging system called the combo one  connector mainly used           in the USA.

2.   The CCS combo 2 connector mainly used in Europe. The third is the Asha demo connector which is used worldwide for cars mainly built by Japanese manufacturers.

3.  The DS Tesla DC connector also used for AC charging and finally  China has their own DC connector based on Chinese gbt standard.

           Now let's see these connectors one by one, the combined charging system or CCS connectors we also call combo R integrated connectors for both AC and DC charging which are derived from type 1 and type 2 connectors for AC charging by adding two extra pins at the bottom for high DC charging amperage the connectors derived from type 1 and type 2 are referred to as combo 1 and combo 2 respectively.

 

 

let's first look at the CCS combo 1 connector in this slide the combo one vehicle connected is shown on the left and the vehicle inlet is shown on the right the vehicle connector of combo 1 is derived from the AC type 1 connector and contains the ground pin and the 2 signal pins namely the control pilot and the proximity pilot in addition to the DC pins are added for fast charging at the bottom of the connector on the vehicle Inlet pin configuration the top part same as the AC type 1 connector for AC charging while the bottom 2 pins are used for DC charging.

                    Similarly, the ccs combo two connectors are derived from the AC type two connectors and keep the ground pin and the two signal pins, namely the control pilot on the proximity pilot, to the DC pins are added on the bottom of the connector for high power DC charging on the same way at the vehicle on that side, the upper part facilitates AC charging from three phase alternating current and at the lower part.

 

                      you have the DC charging as opposed to type 1 and type 2 connectors which only use pulse width modulation or PWM signaling on the power line control pilot.

                    communication from plc is used in both the combo 1 and combo 2 chargers and this is produced on the pilot power line communication is a technology that carries data for communication on existing power lines used for simultaneous transmission of both signal and power transmission the CCS Combo Chargers can supply up to 300 350 amperes at a voltage between 200 and 1000 volts, giving a maximum output power of 350 kilowatts.

                     Keep in mind that these values ​​are continuously updated by the charging standards to meet the voltage and current requirements of new electric cars.

                  The third type of DC charger is the shadow connector, a type 4 eb connector, it has three power pins and six signal pins for this operation, the more it uses the control area network or chin protocol.

 

              In the communication pins for communication between the charger and the car, network communication in the control area is a robust communication standard for vehicles. Decide to let microcontrollers and devices communicate with each other in real time without a host computer from now on the voltage and current and power levels of the shade Moe range from 50 to 400 volts with amperage up to 400 amps.

             Thus, a peak power of up to 200 kilowatts for future charging. EB is expected to charge up to 1000 volts and 400 kilowatts. is powered by a demo, now let's move on to Tesla charger connectors.

            The Tesla supercharger network in the United States uses their own proper charger connector, while the European variant uses a type 2 minoccurs connector, but with DC charging built in, the unique aspect of the Tesla connector is that the same connector can be used for both AC charging and DC charging.

              Tesla now offers DC charging up to 120 kilowatts and it is expected to increase in the future.After all, China has its old DC charging standard and connector which uses the can bus control area network bus for communication, it has five power pins, two for DC and two for low voltage auxiliary power transmission and one for ground and it has four signal pins two for the proximity pilot and two for the network communication in the control area from now on the rated voltage used for this connector or 750 volts or 1000 volts and the current up to 250 amps is supported by this charger, it can already see that fast charging is quite attractive.

 

            Due to the very high charging capacity of up to 300 or 400 kilowatts, this results in very short charging times, but the fast charging capacity cannot be increased indefinitely due to three technical limitations of fast charging.

                     Now let's take a look at these limitations. First of all, high current charging leads to high total losses in both the charger and the battery.

                for example if the internal resistance of a battery is R and the losses in the battery can be simply expressed by the formula I squared R where I is a charging current.

                   Then you will find that the losses increase four times when the current is doubled second.

 

                  The second limitation stems from the battery. When a battery is charged for the first time, the battery's state of charge can only reach 70 to 80% state of charge, this is because fast charging creates a delay between the voltage and the state of charge and this phenomenon increases the faster the battery charging.

                Therefore, the initial charging is typically done in the constant current or CC region of the battery charging and then the charging power is gradually reduced in the constant voltage or CV charging region.

               In addition, the battery charging speed or C speed increases with fast charging and this then leads to a shortening of the battery life.The third limitation comes from the charging cable for any Ev i.e. charger, it is important that the cable flexible and lightweight.

              So that the people can carry the cable and connect it to the car with higher charging capacities, thicker and thicker cables are needed to allow more charging current, otherwise it will get warm from the losses.

                DC fast charging systems can already transfer charging currents up to 250 amperes without cooling today, but in the future with currents of about 250 amperes.

 

                 Where would the charging cables become too heavy and less flexible for use, the solution would be to use thinner cables for the given power with built-in cooling systems and thermal management to ensure that the cables do not get hot this is of course more complicated and expensive than using a cable without cooling, so to pack.