1Advanced drive train components for electric vehicles

Understanding e-Bike Propulsion Systems:The Controller

Robert LankinSeptember 23, 2010

Agenda

• What’s a controller?• Servicing a controller• Selling a controller

2

What’s a controller?

• Electronic module• Between battery and motor• Regulates motor speed• Prevents excessive currents and overheating

3

Controller complexity

• Simplest: on/off switch for DC motor• Variable speed DC motor + twist throttle• Brushless motor with hall sensors• Brushless motor without hall sensors• Pedelec torque sensor• Smart communication with battery• Smart communication with display• Built in diagnostics and programming

4

Incr

easi

ng C

ompl

exity

Simple DC System

5

M1

More Complex System

6

More Complex System

7

M1

Controller

Throttle

Brake Switch

BMS

Display

BottomBracketSensor

More FeaturesMore Complex to Troubleshoot

Agenda

• What’s a controller?• Servicing a controller• Selling a controller

8

Servicing a controller

1. e-bike doesn’t go at all2. e-bike doesn’t go as far or fast as it used to3. e-bike acts or sounds strange

9

Servicing a controller

1. e-bike doesn’t go at all– Check power to controller (battery, fuse, switch,

wiring)– Burnt smell?– Check controller LED for error codes (read manual!)– Check throttle and brake signals at controller– Check motor hall signals (wet?)– Spin hub motor backwards, check for AC voltages –

zero voltage means failed wiring somewhere

2. e-bike doesn’t go as far or fast as it used to3. e-bike acts or sounds strange

10

Servicing a controller

1. e-bike doesn’t go at all2. e-bike doesn’t go as far or fast as it used to

– Weak battery or defective charger– Low tire pressure– Mechanical friction (bearings, alignment,

brakes)– Intermittent operation may be overheating due

to loads, friction, or defective temperature sensor

3. e-bike acts or sounds strange

11

Servicing a controller

1. e-bike doesn’t go at all2. e-bike doesn’t go as far or fast as it used to3. e-bike acts or sounds strange

– Pulsations or dead zones may be bad hall sensor, wet hall sensor, or hall sensor wiring problem

– Erratic forward motion may be faulty or lose connectors

– Conversion kits may have mechanical fatigue in axle, spokes, rear sprocket

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Agenda

• What’s a controller?• Servicing a controller• Selling a controller

13

Selling a controller

• Power rating (250W vs. 500W vs. 750W)– Hill climbing, acceleration, head wind, loads– Compare bikes, compare routes

• Voltage rating (24V vs. 36V vs. 48V)– Higher voltage typically with higher power

• Throttle vs. pedelec– Inexperienced vs. experienced riders

• Feel: smooth and intuitive vs. hesitations– Ride and compare different systems

14

Selling a controller

• Features– Sensorless – fewer service issues, but may need

a running start– Regenerative braking – improved range, perhaps

improved braking feel– Reliability, durability, weather resistance– Integrated diagnostics

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