2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Reconfigurable Power Sources For RSMS Vehicles.

Contents• Select an appropriate battery• Explore various modes of configurability• Shortlist a suitable mode• Use PACE Software to design and implement the

system.• Test the feasibility.  

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

AIM

To design and implement a reconfigurable power source which has the following features:• Adjust capacity based on load requirements.• Easy fitment and removal.• Fully charged battery available at stations.• Transported safely and effortlessly to remote locations

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Need for a Reconfigurable Power Source

• A reconfigurable battery helps in achieving the basic aim of RSMS allowing transportation of different combination of cargo and passengers.

• Allows shift from conventional fuel vehicles to electric vehicles.

• Reduction of charging time thereby increasing productivity.

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Ideal Power Source for RSMSVehicles

Criteria for the battery 1. Affordability2. Ease of availability3. Ease of charging4. Low Weight5. Portability6. Ease of maintenance7. Durability8. Long Range

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

A list of batteries currently in use in electric and hybrid vehicles is shown below

NA

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NA

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

ADVANTAGES

High energy density  Does not need priming when new.  Relatively low self-discharge . Low Maintenance. Available in a range of capacities and power requirements.

DISADVANTAGES

Requires protection circuit . Subject to aging, even if not in use. Transportation restrictions . Expensive to manufacture. Technology evolving.

Lithium ion battery as a power source

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Lead acid battery as a power source

ADVANTAGES• Low cost.• Reliable.• Robust. • Tolerant to overcharging.• Low internal impedance.• Can deliver very high currents.• Indefinite shelf life if stored

without electrolyte.• The world's most recycled

product. 

DISADVANTAGES• Bulky.• Typical columbic charge

efficiency only 70%.• Danger of overheating during

charging• Not suitable for fast charging• Typical cycle life 300 to 500 cycles

.• Must be stored in a charged state

once the electrolyte has been introduced.

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Calculations for required power

Traction Force = [ M * a ] + [ M * g * sin(b) ] + [ sign(V) * M * g * cos(b) * r ] +

[ sin(V+v) * 0.5 * ( air density ) * C * A * ((V+v)^2) ]

M – mass of the car – 800 kga – maximum acceleration of the car – 2 m/s^2g – gravitational acceleration – 9.81 m/s^2b – maximum inclination of road – 10 degrees V – maximum speed of car – 60 km/hr or 16.67 m/sv – maximum headwind speed – 2 m/sr – tyre rolling resistance coefficient – 0.016C – aerodynamic drag coefficient – 0.26A – front area of the vehicle – 1.43 m^2Air density – 1.2041 kg/m^3

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Traction Force ‘F’ = 3164.47 N (per wheel 1582.24N)Traction torque = F * (radius of wheel) = 648.72 N-m ( 324.3 N-m per wheel)Angular Velocity of the wheel ‘w’ = V / (radius of wheel)

= 81.317 rad/sTraction power = F * V

= 52.75 kW ( 26.375 kW per wheel )Shaft torque = (Traction torque) / (efficiency of driving wheel) i.e efficiency of driving wheel = 95%

= 682.86 N-m ( 341.43 N-m per wheel )Power of Electric Machine = Shaft Torque*Angular Velocity of the wheel

= 55.528 kW ( 27.76 kW per wheel )

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Table of speed v/s power required

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Urban Scenario

Critical Success Factors

1. Charging points available every 50 Kms .2. Charging points in commercial as well as residential

areas.3. Power should be nominally priced.4. High speed charging docks at every station.5. Capable of transporting mostly people over short

distances.6. Battery swapping facilities at every station.

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Setting up supercharging stations

Supercharging enables the battery to be charged halfway in under 20 minutesHow regular charging works-•Most electric vehicles (EVs) have an on-board charger that uses a rectifier circuit to transform alternating current from the electrical grid (mains AC) to direct current (DC) suitable for recharging the EV's battery pack.• Cost and thermal issues limit how much power the rectifier can handle, so beyond around 240 VAC and 75 A it is better for an external charging station to deliver direct current (DC) directly to the vehicle's battery pack.

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

How supercharging works• For faster charging, dedicated chargers can be built in

permanent locations and provided with high-amperage connections to the grid.

• In this style of connection, the charger's DC output has no effective limit, theoretical or practical.

• Such high voltage and high-current charging is a DC Fast Charge or level-3 charging (in contrast with less powerful AC charging levels 1 & 2 seen in regular speed charging stations)

• Supercharging stations will be set up at regions of high traffic density inside the city where charging time will be comparable to refuelling time for fuel based vehicles.

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Battery specifications for urban

• Battery capacity =25 KWh • Panasonic cells -3400 mAh at 3.7 V• Total no. of cells required =1987• No. of cells in a group=74• Total no. of groups required=27• No. of groups in a module=6• Total no. of modules required=5

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Semi-Urban Scenario

Critical Success Factors1. Charging points be made available every 100

Kms 2. Charging points installed along major highways

and in smaller towns in between cities.3. Power should be nominally priced .4. Batteries capable of hauling combination of

cargo and passengers over medium distances.5. Battery capacity to be increased compared to

urban vehicles to haul cargo.

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Battery specifications for semi-urban

• Battery capacity =30 KWh • Panasonic cells -3400 mAh at 3.7 V• Total no. of cells required =2385• No. of cells in a group=74• Total no. of groups required=33• No. of groups in a module=6• Total no. of modules required=6

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Rural ScenarioCritical Success Factors

1. Charging points available at major villages and towns.

2. Assistance to be provided in case of a battery discharge or vehicle breakdown.

3. Batteries capable of powering large capacity cargo vehicles.

4. High efficiency and low operating costs in addition to cash incentives for first time buyers.

5. Battery capacity to be increased compared to semi urban vehicles to haul cargo.

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Battery specifications for rural

• Battery capacity =40 KWh• Panasonic cells 3400 mAh at 3.7 V• Total no. of cells required=3180• No. of cells in a group=74• Total no. of groups required=43• No. of groups in a module=6• Total no. of modules required=8

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Battery swapping To incorporate a battery swapping facility in charging

stations the RSMS vehicle is designed to accommodate easy battery swapping

Advantages-• Unlimited range over the route which has access to

battery swapping stations• The driver does not own the battery in the car,

transferring costs over the battery, battery life, maintenance, capital cost, quality, technology, and warranty to the battery switch station company.

• Contract with battery switch company could subsidize the electric vehicle at a price lower than equivalent petrol cars.

2015 ANNUAL FORUM

Presented by: Name, Institution or Company

Design of RSMS battery swapping mechanism

2015 ANNUAL FORUM

Presented by: Name, Institution or Company