Regenerative Braking Group 12 Jonathan Bourget Duncan Elliot Andrew Crooks David Thompson Supervisor – Dr. Allen

Introduction Majority of motor vehicles on the road are powered by an internal combustion engine Internal combustion engines Large losses to heat Also losses to parasitic loads on the engine Loads run directly off the output of the engine The common alternator is a parasitic load on an engine Design Group 12 Dalhousie University

Purpose To eliminate the load of an alternator on an engine This will increase the overall efficiency of the common motor vehicle Use the kinetic energy of a vehicle just before braking and create electricity instead of converting that energy to heat via friction Design Group 12 Dalhousie University

Efficiency Many advancements have been made in making the internal combustion engine more efficient The common gasoline engine averages out at % efficiency at max power In the operating ranges for an urban drive it’s about 10-12% efficient Design Group 12 Dalhousie University

2016 CAFE Standards Corporate Average Fuel Economy Unchanged 27.5 US mpg since % more strict standards in 2016 GM, Ford, and Chrysler face 23.9% increase in their cars from 2008 Improvements rely on a number of technologies Electric/Hybrid powertrains More efficient conventional powertrains Design Group 12 Dalhousie University

Design Requirements Generate enough power to eliminate the need of a conventional alternator Implement mechanical brakes in tandem with the generation system Construct a fully functional prototype scaled down from an average car Test the prototype based on realistic everyday driving dynamics Design Group 12 Dalhousie University

Design Requirements Safety Ensure mechanical braking is always available Separate fuel system and high power electric components from driver by firewall Shield all mechanical components from user Adhere to MECH 4--- timeline and documentation requirements Create and update team website with team information and documents Design Group 12 Dalhousie University

Power Available To find the available kinetic energy at a point in time To find the available power Need the average initial speed when braking is initiated and duration of braking Use Vehicle monitoring software to log typical commutes. Design Group 12 Dalhousie University

Driving Analysis Urban and Rural Commutes were simulated with the following results Braking found using a numerical analysis of velocity log Design Group 12 Dalhousie University SituationDistance (km) Average Initial Speed (km/h) Duration of Braking (% of time) Urban73718%-35% Rural44713%-20%

Urban Commute Design Group 12 Dalhousie University

Rural Commute Design Group 12 Dalhousie University

Needed Energy Measured the Current and Voltage that are used in a car Using a multi-meter to measure voltage and a DC current meter to measure the current Used to determine electrical load due to auxiliaries in a car Under normal driving conditions the car requires 14 Volts 48 Amps Design Group 12 Dalhousie University

Scaling System scale determined by mass of test vehicle Design Group 12 Dalhousie University

Design Overview Design Group 12 Dalhousie University GeneratorGenerator ActuationActuation ControllerController BatteryBattery AuxiliariesAuxiliaries ConverterConverter ControllerController

Generator Selection What we know How much Energy is Required(120W Steady State) How often Brake actuated (20%) Therefore 700W needed What Type of Generator Brushless DC Traditional DC Alternator When should the Generator Produce Max Power At What RPM What Gear Ratio is needed Design Group 12 Dalhousie University

Generator Selection Cont. Necessary Mounting Shaft Selection Intermediate Shaft Gear Ratio Pulleys and Belt from Intermediate Shaft to Generator Design Group 12 Dalhousie University

Converter Purpose: Drop Generator output voltage from V to a usable V for charging battery Audio converters: too low power rating Solar Converter: Expensive custom construction Sufficient resources are available within the department to have one designed and built Design Group 12 Dalhousie University

Controller Controller Specified: KBL24201,12V-24V,200A Regenerative function built in Built in battery voltage monitoring Accepts 0-5V signal inputs Design Group 12 Dalhousie University

Battery Nominal voltage of 12 volts High power, dual purpose engine start and deep cycle sealed lead acid battery 1000 amp rating at 32 deg F Can be charged with a voltage of 13.8 to 15 volts Design Group 12 Dalhousie University

Brakes and Actuation Brakes need to be reinstalled Actuation of generator takes place when brake pedal is actuated Design Group 12 Dalhousie University

Design Analysis Power generation requirement Capacity factor based on real-world driving Analysis of generator performance Power curves Determination of gear ratio Simulation of stopping with a combination of brakes and generator Maximum system performance Performance under constant Deceleration Design Group 12 Dalhousie University

Simulation of Deceleration Constant rate of deceleration Power to each part of system Based on torque curve as a motor, typical braking cycle on urban route Design Group 12 Dalhousie University

Generator Performance Energy Generated in a typical deceleration: 1.5 Wh Design Group 12 Dalhousie University

Generator Performance Energy Generated in a typical deceleration: 1.5 Wh Equivalent continuous power: 180 W Design Group 12 Dalhousie University

Summary of Analysis 180 W continuous exceeds design requirement of 113 W This represents 1.12 kW full scale Put in Perspective VW Golf rated at 9.8 L/100km city Alternator would consume 3.2 L/100km (at 1.12 kW) Our system could save 2.0L/100km (at 700 W) Design Group 12 Dalhousie University

Budget Design Group 12 Dalhousie University Part Target Cost Generator Brushless DC $ 1,200 Voltage Converter $ 100 Sprokets for shaft $ 23 Controller $ 370 Controller PC Cable $ 35 Sensor Wires $ 45 Switch $ 25 Wiring $ 10 Brakes Master Cylinder $ 65 Solid Brake Line $ 40 Flexible Brake Line $ 45 Brake Fittings $ 30 Battery $ 230 Costs involved in Baja Steel Plate $ 100 Light Bulbs $ 130 Total: $ 2,500.00

Thanks Special Thanks to the following for their help Dr. Peter Allen Dr. Lucas Swan Mark MacDonald Albert Murphy Thanks to Shell for the funding for our project. Questions? Design Group 12 Dalhousie University Reference Picture of golf taken from Picture of alternator taken from