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The development of Charging station infrastructure plays a major role in the development of EV ecosystem. The Committee on standardization of protocol for Electric Vehicles (EV) Charging Infrastructure has come out with recommendations entailing specifications for AC and DC charging for electric vehicles. These standards are called – Bharat EV Charger AC-001 and Bharat EV Charger DC-001. India will deploy both CHAdeMO and Combined Charging System (CCS) fast-charging technologies, besides the existing Bharat Standard, at its public electric vehicle charging stations.
The home private chargers are generally used with 230V/15A single phase plug which can deliver a maximum of up to about 2.5KW of power. Thus, the vehicles can be charged only up to this rate. The billing for power is part of home-metering. This will be continued till a policy evolves to charge the home users differently for EV use. Also, Bharat EV Specs recommends using the IEC 60309 Industrial connector from both ends.
For charging outside the home premises, Bharat EV standards recommend that the electric power needs to be billed and payment needs to be collected. The power utilities may also want to manage power drawn by these chargers from time to time.
Normal AC charging
As mentioned above, electric 2-wheelers, 3-wheelers, and 4-wheeled vehicles in India has an onboard charger that charges at the rate of around 2.5kW to 3kW. This AC 2.5KW or 3KW chargers could fast charge a 2-wheeler (for a battery with an energy density of 2KWh) in an hour’s time; 4-wheeler or larger vehicles with batteries of 12 KWh or more will be charged in five to six hours.
AC Plug Connectors
Indian electric cars use the IEC 60309 Industrial Blue connectors and Bharat EV specifications recommend using this plug.
Global EV’s use the IEC 62196 Type 2 connector (commonly referred to as Mennekes). This plug was selected by the European Commission as an official charging plug within the European Union. It has since been adopted as the recommended connector in countries outside of Europe.
The EV shall be connected to PMAO (Public metered AC outlet) for the conductive energy transfer function. The system will have
the following general specifications:
- PMAO is supplied with three-phase AC power and outputs single phase AC power.
- Energy Transfer Mode is Conductive.
- Each outlet will have up to three independent charging sockets.
- The PMAO has built-in metering, safety & monitoring.
- PMAO and Central Management System communicate with each other to serve purposes of firmware, reservation, cancellation, addition, and deletion of PMAOs, etc.
- A.C. Supply System is 3 phase, 5 wire AC system (3 phases + N + PE)
- Nominal Input Voltage is 415V (+6% and -10%)as per IS 12360
- Input Frequency is 50Hz ± 1.5 Hz
- Input Supply Failure back-up: Battery backup for a minimum of 1 hour for the control system and billing unit. Data logs should be synchronized with CMS during the backup time, in case the battery drains out.
- Number of Outputs: 3
- Type of each output: A.C., 230V (+6% and -10%) single phase as per IS 12360
- Output Details: 3 Independent charging sockets as per IEC 60309, Female connector to be used on the PMAO Side
- Output Current: Three vehicles charging simultaneously, each at 15A current
- Output Connector Compatibility: IEC 60309 Industrial Blue connectors to be used.
- Connector Mounting: Angled connector mounted looking downwards for outdoor use.
- Double-pole breaking RCD (IEC 60309 Blue connector) of less than 30mA.
- Limiting Output Current: Circuit breaker for each outlet limited to 15A current output.
- The breaker should be reset to resume operation. Output selection: the breaker inside to be energized in sequence – one round of all
- three phases before the second round.
- Socket readiness: An LED to indicate that the socket is ready.
- Isolation: Input and outputs should be isolated. Outputs should be isolated from each other to avoid cross-talk
The Bharat EV Specifications also discusses the communications that need to occur between the EVSE and an electric vehicle. Also, the communication that needs to happen between the EVSE and a remote server.
- The EVSE needs to communicate with BMS of the battery pack in the EV, to enable it to charge at the right rate for maintaining SOC of batteries. The physical layer for this communication will be CAN, as it is commonly used by vehicle manufacturers in India.
- Communication between EVSE and Central management system (CMS) located at the power utility company, so as to enable the maximum charging rate to be controlled depending upon the rates of grid supply. This will also enable metering at different rates. This is critical as whenever vehicles consume large currents and the grid should be able to supply it. This will also enable the reservation of chargers by users.
- The communication protocol used will be OCPP. This will be carried on the Internet, using wired media or wireless (Wi-Fi or GPRS or 3g/4g wireless).
AC001 Specification Summary
Sl.NO Parameters Requirements General Requirements 1 EVSE Type AC 2 Energy Transfer Mode Conductive Input Requirements 1 AC Supply System Three-Phase, 5 Wire AC system (3Ph.+N+PE) 2 Nominal Input voltage 415V (+6% and -10%) as per IS 12360 3 Input Frequency 50Hz, ±1.5Hz 4 Input Supply Failure backup Battery backup for minimum 1 hour for the control system and billing unit. Data logs should be synchronized with CMS during back up time, in case battery drains out. Environmental Requirements 1 Ambient Temperature Range 0 to 55°C 2 Ambient Humidity 5 to 95% 3 Ambient Pressure 86 kpa to 106 kpa 4 Storage temperature 0 to 60°C Mechanical Requirements 1 Suggested Cable Security PMAO and the vehicle connector outlet to have provision for locking mechanism during charging to ensure the safety of the cable 2 Mechanical Stability Shall not be damaged by mechanical impactimpact energy: 20 J (5 kg at 0.4 m) 3 IP Ratings IP 54 4 Cooling Air-cooled or forced air-cooled to protect the equipment against temperature hazards Output Requirements 1 Number of outputs 3 2 Type of each output 230V (+6% and -10%) single-phase, 15A as per IS 12360A.C. 3 Output Details 3 Independent charging sockets, given in Annex-A 4 Output Current Three Vehicles charging simultaneously, each at 15Acurrent 5 Output Connector Compatibility IEC 60309 6 Limiting output current Circuit breaker for each outlet is limited to 15A current output. The breaker should be reset to resume operation 7 Connector Mounting Angled connector mounted looking downwards for outdooruse 8 Isolation Between Input & Output; Between all outlets with proper insulation User Interface & Display Requirements 1 ON- OFF (Start-Stop) switches Simple Push button type 2 Emergency stop switch Mushroom headed Push-button type (Red color) 3 Visual Indicators Error indication, Presence of input supply indication, Charge process indication and other relevant information 4 Display & touch-screen size Minimum 6 inches with 720 x 480 pixels 5 Display Messages EVSE should display appropriate messages for the user during the various charging states like• Vehicle plugged in / Vehicle plugged out• Idle / Charging in progress – SOC• Fault conditions; metering: units consumption; Durationsince the start of charge, Time to charge, kWh 6 User Authentication Using mobile application or User interface (OCPP gives only a field mandate, media to be used is open) 7 Metering Information Consumption Units Billing & Payment Requirements 1 Metering Metering as per units’ consumption for charging each vehicle 2 Billing Grid responsive billing 3 Payment BHIM and Bharat QR compliant mobile application payment Communication Requirements 1 Communication between EVSE and Central Server Open Charge Point Protocol (OCPP) 1.5 protocol.Should be upgraded to the next version of OCPP whenever it is released including OCPP 2.0 which is a draft version now Should enable handshaking between EVSE and CMS for discovery.It should authorize the operation before electric vehicles can start or stop charging. EVSE should respond to CMS for various queries and commands like reservation, cancellation. 2 Metering Grid responsive metering as per units’ consumption of each vehicle 3 Interface between charger and central management system(CMS) Reliable Internet Connectivity Protection & Safety Requirements 1 Safety Parameters Safety and protection to be ensured for India specific environment (As per AIS 138 Part1) 2 Start of Charging The outlet will be locked and covered, the connector will be exposed to charging only after user authentication using the user interface or mobile application. Only when the lock opens and the connector are properly connected, the switch/relay will turn ON to feed power to EV. The lock will be opened only after full charging and authentication by the user or the operator. Once disconnected, the charging session terminates 3 Power failure If there is a power failure, the user is indicated about this. The charging resumes when the power comes on. If the user wants to terminate the session during a power failure, the user can shut-off the switch and remove the plug 4 Interruption of Charging O Connector terminals to be mounted with temperature sensors to avoid the burning of connectors. Safety mechanism to trigger switching off the charging at temp.>80°C. In such a situation, an appropriate signal will be sent to turn the switch/relay OFF to stop the charging. Once disconnected, the charging session terminates.O If the above locking mechanism is mandated then the following point won’t be required: If the plug is taken out (for more than 2 seconds) and then reinserted for charging, the charging-session will disconnect. A new session will be required to continue charging to ensure that no one can remove a vehicle being charged and insert their own cable and use the infrastructurewithout paying or at someone else’s account
Bharat AC001 Specification
Know more on the EV charging ecosystem in India from: Components of EVSE | Bharath DC001 | Bharat AC001 | EVSE Growth Trends | Battery Swapping Growth Trends | EVSE Cost components | EVSE installation costs | Battery swapping in India | Indian EVSE Stakeholders | Charger Standards | Current Indian EVSE status | EVSE Challenges | EVSE during 2020-2030 |
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