COMBINED CHARGING SYSTEM(CCS)
The Combined Charging System is a universal charging system for electric which integrates all
established AC charging solutions with ultra-fast DC charging in a single system. Only one
charging interface will be required at the vehicle for single-phase AC charging, fast three-phase
AC charging as well as ultra-fast DC charging at Combined Charging System Disclaimer home
or public stations home or public stations. The Combined Charging System enhances today´s
regional solutions towards one global integrated system. The Combined Charging System
represents the future of fast charging and maximizes the integration of electric vehicles into
future smart grids. The Combined Charging System is an open international standardized system
and mainly driven by Audi, BMW, Chrysler, Daimler, Ford, General Motors, Porsche and
Volkswagen.
The CP is used for communication (exchange of control signals)
between the EVSE and the EV. Using a 1 kHz square wave at ±12 V
between the CP and PE line provided by the EVSE, the amplitude can
CP Control Pilot be manipulated by the EV to control charging (PWM -
communication). It is also used as a safety function. As soon as the CP
connection is interrupted, the charging voltage is switched off.
The PP is used to prevent movement while the EV is connected to the
EVSE. The EV can only drive away when the charging plug is
PP Proximity Pin /
unplugged. In the Type 2 connector the PP is additionally used for a
Plug Present
detection of the charging cable current load capacity. In the Type 1
connector this pin is used for manually unlocking the plug.
CS Connection Signal In older standard versions the PP of the Type 1 AC plug is called
Connection Signal (CS) in IEC 62196 and Proximity Detection (PD)
PD Proximity Detection
in SAE J1772.
PE Protective Earth PE is a line that is earth grounded on the EVSE side. By that also the
EV is earth grounded. It is a way to deliver current to the earth to
prevent electric shocks and it is used as reference pin for CP and PP.
CCS Pinout:
CCS Authorization:
1.External Identification Means (EIM)
EIM is an identification method that requires additional user interaction or other identification
operations. This can be a smartphone app, credit card, RFID card or a license plate scanning at a
charging station. The charging station uses an OCPP request to send the token ID to the charging
station management system where the token ID is matched with a list. A successful match sends
an authorization response back to the charging station and an unsuccessful match sends an error
state.
2.Auto charge
With this user-friendly authorization method introduced by Fastnet for public charging, the EV is
identified using its vehicle ID, the EV controller MAC address, like RFID (EIM) authorization.
Auto charge can be securely used only in closed charging parks rather than public charging -
stations, due to security concerns. It does not work with vehicles that dynamically change their
MAC address and is not standardized.
3.Plug and Charge (PnC)
PnC enables secure automatic identification and authorization for charging by simply connecting
the EV. The method works with an asymmetric key algorithm supported by a public key
infrastructure (PKI) and certificates stored in the EV and EVSE as defined in ISO 15118.
4.Data Security
The increasing electrification of mobility and high number of accessible EVSEs also drive the
need for improved security in communication, identification, authorization and payment of
charging. This is reflected in the progressing standardization of CCS too. The system uses TLS
encryption of the high-level communication and PnC as a secure means of authorization using
asymmetric keys and a PKI.
Communication Protocols
Innovative solutions are becoming increasingly available to make electric mobility mass-market-
capable. An important part of this is the charging technology. In this context, the term smart
charging is used for charging systems of electric or hybrid vehicles according to standards like
ISO 15118 and DIN SPEC 70121.
To achieve interoperability between the vehicle and the infrastructure, the standards IEC 61851,
ISO 15118, DIN 70121 and VDV 261 exist. They specify the charging communication and
ensure correct data exchange before and during the actual charging process.
Low-Level Communication:
The PWM is used for low-level communication between the electric vehicle (EV) and the
electric vehicle supply equipment (EVSE). The signal voltages alternate between two defined
levels.
+12 V State A No EV connected to the EVSE
+9 V State B EV connected to the EVSE, but not ready for
charging
+6 V State C Connected and ready for charging, ventilation is not
needed
+3 V State D Connected, ready for charging and ventilation is
required
+0 V State E Electrical short to earth on the controller of the
EVSE, no power supply
-12 V State F EVSE is unavailable
The EVSE specifies the maximum charging current for the EV via the duty cycle. The PWM
signal is applied to the circuit of control pilot. The standard IEC 61851-1 defines the meaning of
the applicable duty cycle values.
Duty cycle < 3 % No charging allowed
3 % ≤ duty cycle ≤ 7 % Force high-level communication protocol according
to ISO 15118 or DIN 70121
7 % < duty cycle< 8 % No charging allowed
8 % ≤ duty cycle< 10 % Max. current consumption for AC charging is 6 A
10 % ≤ duty cycle ≤ 85 % Available current = duty cycle * 0.6 A
85 % < duty cycle ≤ 96 % Available current = (duty cycle - 64) * 2.5 A
96 % < duty cycle ≤ 97 % Max. current consumption for AC charging is 80 A
Duty cycle > 97 % No charging allowed
High-Level Communication:
Power Line Communication (PLC):
For the EVSE and EV communication IP-based protocols are used. PLC technology with a
dedicated physical connection (CP, PE) is used for this purpose. In this system, the data stream is
modulated onto the PWM signal. It is more familiar under the names HomePlug AV and IP-over
powerline in the consumer products field. In the vehicle’s charge control module, a Transmission
Control Protocol / Internet Protocol (TCP/IP) stack is used for communication.
PLC is used for high-level communication in CCS.
Signal Level Attenuation Characterization (SLAC):
The SLAC mechanism of Home Plug Green PHY works according to the request/response
method and it is compliant to ISO 15118-3 and DIN SPEC 70121.
First, the vehicle sends a broadcast message and any EVSE that receives this message (crosstalk)
computes the signal strength and sends it back to vehicle. Then SLAC ensures that the vehicle
and EVSE are physically connected by measuring the attenuation: the EVSE with the highest
received signal strength is defined as the correct EVSE. The vehicle and charging station agree
on a unique identification feature that must be contained in all subsequent messages of the same
SLAC session. The SLAC protocol is supported by AUTOSAR basic software components.
Controller Area Network (CAN):
CAN is a message-oriented multi-master protocol for quick serial data exchange between
electronic control units in automotive engineering and factory automation.
CAN is used for high-level communication in DC GB/T and DC CHAdeMO.
Electrical Vehicle Power Line Communication (EVPLC):
Power line communication (PLC) system for vehicle that allows in-vehicle communication for
the transmission of sensor messages/data and. Now a day’s more sensors are inserted in vehicles
as functional safety features PLC will offers low cost, less complexity of wire networking. This
Power line communication will add the advantage of lower cost of wires, wiring manufacturing
process and hence increase productivity. This technology is very useful for future electric
vehicles (E – Vehicles) because to increase the distance coverage of E – vehicle manufacturers
are more focusing on reducing the weight of vehicle so that vehicle can cover more distance in
single charge of battery.
Block diagram of power line communication:
The power line communication block diagram comprises a power line transmitter and
power line receiver.
Battery: Vehicle battery is the power supply for all vehicle electronics.
Power supply: power supply is the voltage converter to convert battery voltage to 5V
output for digital electronics.
Temperature sensor, Fuel level sensor, Limit switch : These are sensors interfaces to
transmitter.
LCD: LCD displays the transmitted and received data form transmitter and receiver
respectively.
Transmitter MCU: Microcontroller unit is to read the sensors data in analog form and
converting into digital through ADC channel. This converted data is sent to transmitter.
Power Line Transmitter: Power line transmitter will send the data received from
controller UART overpower wire, in the form of high frequency pulses.
Power Line Receiver: Power line receiver will filter out data pulses from power wire.
Filtered data pulses are sent to receiver MCU for displaying on LCD.
Receiver MCU: Receiver MCU receives UART pulses from power line receiver and it
will display over LCD.
PLC Tuning:
Power-Line Communication (PLC) is used for charging electric vehicles around the world and
is a must-have in today’s electric vehicle (EV) market. PLC allows the charging station (aka
electric vehicle supply equipment or EVSE) and the EV to negotiate charging sessions, allowing
various charging profiles and potentially to negotiate payment. Dana’s M560 and M580 modules
have PLC capability built in.
Power-Line Communication (PLC) as depicted in ISO 15118-3 and DIN 70121 specifies power
spectral density (PSD) limits of the HomePlug Green PHY PLC signal injection on the Control
Pilot line for vehicle charging. HomePlug Green PHY is the standard for PLC signals used in
vehicle charging called out in ISO 15118. Attenuation levels specified in the standards allow the
differentiation between PLC signals on a connected charging station from crosstalk with a
neighboring charging station. Higher than specified PSD on the PLC signal could cause
disturbances in the Control Pilot detection, while having a signal too low could be interpreted as
crosstalk or cause packet loss during the charging session. Having proper tuning provides the
best environment for ensuring proper connection between a charging station and the electric
vehicle.
Every vehicle model will have differences in mounting location and wiring harnesses for the
charge controller module, which causes the attenuation on the Control Pilot line to vary. These
differences may affect the entire spectrum of frequencies used for PLC, or only a subset. The
default configuration of Dana’s modules will work in almost every situation, but with the
different harness designs, there is the possibility of not meeting the DIN and ISO standards.
Tuning, therefore, is essential for each vehicle model and Dana has expertise on the tuning
process of our M560 and M580 modules for use in our customers’ vehicles.
The maximum PSD of the PLC signal at the electric vehicle socket is -73dBm/Hz, with the target
being -75dBm/Hz, as specified in ISO 15118-3. Dana can take measurements and, using some
proprietary software, modify the PSD across the frequency spectrum to bring the entire PLC
frequency band into compliance. Here is an example of a measurement taken on a pre-tuned and
post-tuned module. Note that there are some frequencies with very low values, which are
notched frequencies called out in the ISO and DIN standards. Additionally, note that the dBm
value targeted is about -35dBm because with the resolution bandwidth used, the dBm/Hz ends up
at the target of -75dBm/Hz.Once Dana creates an updated configuration for the customer’s
vehicle, that configuration is used to program modules during production, eliminating the need
for the customer to be concerned with having the correct configuration on the module. This
configuration is not saved in the same memory as the application space, so the customer can
continue to develop their vehicle application as usual.
