Detailed presentation on the basics of an electric vehicle, comparison of different motors for EV application, comparison of different batteries for EV application, Charging infrastructure for EV in India and a brief on BMS(Battery Management System).
6. Present scenario of Electric Vehicles in India
• Free EV charging points
• Regulated rates for charging
• Reassess EV charging infrastructure
• Community charging stations
• Investments by large fleet operators
• Battery Swapping technology
• Government initiative policies
9. What are the challenges?
• Range Anxiety
• Lack of charging infrastructure
• Different specifications and requirements
• Time for charging
• Availability of Vehicles
• Limited life span of battery
• India does not have Lithium ion reserves to support a large domestic
market for electric vehicles
• CORE PROBLEM : Different standards for battery and other engineering
components
10. Solutions
• Common Replaceable Battery Standard for electric vehicles
• EV Charging infrastructure as unified as petrol stations
• Solar powered charging booths
• Smart Map for Charging Stations
• Cost of Electric Vehicles
• More focus on R&D based on standardized infrastructure
• Safe Battery disposal mechanism
13. Key Components of All Electric Vehicle
1. Auxiliary Battery
2. Traction Battery Pack
3. Charging Port
4. On-Board Charger
5. Electric Traction Motor
6. Power Electronics Converter
7. DC/DC Converter
8. Thermal System (cooling)
15. Motors commonly used in EV
• DC Brushed motors
• BLDC(Brush Less DC) motors
• Induction motors
• Synchronous motors
• SRM (Switched Reluctance Motors)
16. Important Parameters for Comparison of
different types of motors used in EV
• Power to Weight Ratio
• Torque-speed characteristics
• Efficiency
• Cost of Controllers
• Cost of Motors
19. Torque-Speed Characteristics
Torque versus speed characteristics
of DC Series Wound Motor
Torque versus speed characteristics
of DC Shunt Wound Motor
Torque versus speed
characteristics of Switched
Reluctance Motor
20. Efficiency
Motor type
Peak efficiency
(Percent)
Efficiency at 10% load
(Percent)
DC Brushed Motor 85-90 80-85
DC Brushless Motor >95 70-80
AC Induction Motor >90 >90
Synchronous Motor >92 80-85
Switched Reluctance
Motor
90-95 >90
Efficiency comparison of different electric motors
24. Important Factors for deciding the battery
to be used
1. Performance
2. Life Span
3. Cost
4. Safety
5. Specific Energy and Specific Power
6. Charging Time
25. Types of Batteries for all electric vehicles
1. Lead-Acid Batteries
2. Nickel Metal Hydride
3. Nickel-Cadmium
4. Lithium Ion Batteries
4.1 Lithium NCA
4.2 Lithium NMC
4.3 Lithium Manganese Oxide
4.4 Lithium Titanate
4.5 Lithium Iron Phosphate
27. Why Lithium Ion batteries?
• Having excellent specific energy and low self-discharge rate, it appears that
variants of Li-ion batteries are now the dominant type that are currently used in
BEVs.
• Meanwhile, lead acid and NiMH batteries no longer appear to be appropriate for
the use, though these batteries are still frequently used in the automotive
industry.
• There are different types of lithium-ion batteries and the main difference
between them lies in their cathode materials.
• Different kinds of lithium-ion batteries offer different features, with trade-offs
between specific power, specific energy, safety, lifespan, cost, and performance.
29. CHARGING INFRASTRUCTURE IN INDIA
Public Charging Infrastructure is a critical component in the acceleration of
adopting EVs in India.Points to work upon for a proper charging infrastructure in
India:
• Governmental support for rollout (NITI AAYOG etc.)
• Availability of electricity at sufficient level in the planned locations .
• Number of charging stations needed and their locations - availability of sites
for the charging stations - type of charging station needed at each location.
• Rules and regulations relevant for the deployment and safety regulations.
• Budgeting for the deployment of the EV charging infrastructure and installation.
• Discussions with stakeholders and partners on rollout - further location planning
for grid capacity
30. CHALLENGES TO CHARGING
INFRASTRUCTURE IN INDIA
1.Standardizing voltages and communications between battery and chargers.
2.To define a standard protocol which will let the BMS communicate with the
charger and let the charger know about the current it will feed to the battery.
3.Finding the right place for charging station.
4.Range Anxiety.
5.Congestion at charging stations due to slow charging of EVs.
31. BATTERY SWAPPING TECHNOLOGY
• A battery swapping and charging station is an energy refueling station, where,
a. EV with depleted batteries can swap them with fully charged batteries,
b. The depleted swapped batteries are charged.
33. BATTERY MANAGEMENT SYSTEM
Important Battery pack (typically composed of a series of a few batteries or cells)
parameters of an Electric Vehicle:
• Ampere-hour Capacity.
• Specific Energy. (Wh/kg)
• Specific Power. W/kg
• Energy Density. (Wh/l)
• Internal Resistance.
• Depth of Discharge (DOD)
• Life Cycles (number of cycles).
34. BATTERY MANAGEMENT SYSTEM
• A Battery Management System (BMS) is an electronic regulator that monitors and controls
the charging and discharging of rechargeable batteries used in
Electric Vehicles.
• Protects the battery from operating outside its safe operating area.
• Monitors its state.
• Controls its environment, authenticates it and /or balances it.
• Control the recharging of the battery by redirecting the recovered energy (from regenerative
braking) back into the battery pack .
35. BATTERY MANAGEMENT SYSTEM
A BMS may monitor the state of the battery as represented by various parameters,
such as:
● Voltage
● Temperature
● State of charge (SOC)
● State of health (SOH)
● Coolant flow
● Current
36. BATTERY MANAGEMENT SYSTEM
A BMS may protect its battery by preventing it from operating outside its safe
operating area
● Over-current (may be different in charging and discharging modes)
● Over-voltage (during charging)
● Under-voltage (during discharging), especially important for lead–acid and Li-
ion cells
● Over-temperature
● Under-temperature
37. BATTERY MANAGEMENT SYSTEM
BMS topologies fall in 3 categories:
● Centralized: a single controller is connected to the battery cells through a
multitude of wires.
● Distributed: a BMS board is installed at each cell, with just a single
communication cable between the battery and a controller.
● Modular: a few controllers, each handing a certain number of cells, with
communication between the controllers.
38. CENTRALISED TOPOLOGY
• In centralized topology, a centralized master control unit is directly connected to
each cell of the battery pack.
• The control unit protects and balances all cells while providing various other
functions.
39. DISTRIBUTED TOPOLOGY
In distributed topology, voltage monitors and discharge balancers with digital
communications that can cut off the charger and report its status are placed on
each cell.
40. MODULAR TOPOLOGY
• In the modular structure, several slave controllers are used to consolidate the
data to a master controller.
• No printed circuit boards are necessary to connect the individual cells.
41. References
Forbes Survey
• COMPARISON OF ELECTRIC MOTORS FOR ELECTRIC VEHICLE
APPLICATION
(IJRET: International Journal of Research in Engineering and Technology
eISSN: 2319-1163 | pISSN: 2321-7308)
• BCG Research (Boston Consultancy Groups)
• Tesla’s Blog
• Battery management system for electric vehicle applications-
University of Windsor, Canada-RUI HU
