This document discusses the design of a charging module and charging balancing module for an electric vehicle battery pack. The objectives are to ensure balanced charging of all battery cells to avoid overcharging. It will analyze these systems for a 96V 100Ah lithium-ion battery pack in a Proton Saga electric vehicle. Key aspects that will be evaluated include voltage, current, state of charge during charging. The document outlines the problem of unbalanced charging and different charging methods. It also presents options for charge balancing circuits and control strategies.

1. Design of Charging Module
and Charging Balancing
Module for Electric Vehicle
By:
Muhammad Suhaimi Bin Adanan Battery Pack
Supervisor:
Mohd Rezal Mohamed

2. INTRODUCTION
• Any electric car that uses batteries needs a
charging system to recharge the batteries. The
charging system has two goals:
– To pump electricity into the batteries as quickly as
the batteries will allow
– To monitor the batteries and avoid damaging them
during the charging process

3. OBJECTIVES
• To design a charging module and charging balancing
module for EV battery pack.
• To ensure that all cells capacity are balance during
charging.
• To avoid overcharge during battery charging.

4. PROJECT SCOPE
• This project will analyse the charging module and
charging balancing module for electric powered
Proton Saga BLM.
• Battery type: Lithium Iron Phospate (LiFePO4)
• 96V 100Ah

5. PROBLEM STATEMENT
• If the charging process is done without charge
balancing, the batteries are not at the same SOC.
• In this case, the batteries with less restored
energy will be exhausted first when the battery
bank is reused.
• For this reason, charge balancing should be
included in the charging control of series-
connected batteries.

6. PARAMETERS
• Parameters that will be analysed are:
o Voltage
o Current
o State of Charge (SOC)

7. SOC MEASUREMENT
The state of charge (SOC) is the
present capacity of the battery. It
is the capacity that remains after
Current
Sensor
discharge from a top-of-charge
Load condition.
i(t) dq
+ - i (t )
dt
dSoCT dq
Battery Qt
i(t )dt
t
SoCT (t ) QT i( )d
0

8. Charging Discharging
Module Module
LiFePO4
96V
Charging 100Ah Discharging
Balancing Battery Packs Balancing
Module TC Module
Battery Monitoring Unit

9. CHARGING MODULE

10. THE PROS AND CONS OF EACH
CHARGING METHOD
Method Advantages Disadvantages
Constant current method Has ability of limited current It is easy to overcharge in
to prevent the over current later stage
of initial charge
Constant voltage method Has ability of limited voltage Easy to over current in initial
to prevent the over voltage stage
Constant current / constant Can limit voltage and current Charge time is too long
voltage method
Pulse charge method Can reduce the polarization Control is complex
to prevent the battery
temperature rise
ReflexTM charge method Can reduce the polarization Control is complex
to prevent the battery
temperature rise

11. http://www.ti.com/solution/ev_hev_charger_level_1_2

12. CHARGING BALANCING MODULE

13. Balancing Methods Balancing Major Components Needed Best Modular
Nature to Balance an n Cell String Effective Design
Period Capability
Dissipative Shunt Resistor Shunting n Switches, n Resistors Recharging Easy
Analog Shunting Shunting n Transistors Recharging Very Easy
PWM Controlled Shunting Shunting 2(n-1) Switches, n-1 Recharging Moderate
Inductors
Boost Shunting Shunting n Switches, n Inductors Recharging Moderate
Complete Shunting Shunting 2n Switches, n Diodes Recharging Moderate
Switched Capacitor Shuttling 2n Switches, n-1 Capacitors Recharging & Easy
Discharging
Single Switched Capacitor Shuttling 2n Switches, 1 Capacitor Recharging & Poor
Discharging
Step-Up Converter Energy Converter n Isolated Boost Converter Recharging Easy
Multi –winding Energy Converter I n Winding Transformer Recharging Very Poor
transformer
Ramp Converter Energy Converter 1 n/2 Winding Transformer Recharging Very Poor
Multiple Transformer Energy Converter n Transformer Recharging Easy
Switched Transformer Energy Converter n+3 Switches 1 Transformer Recharging Moderate
Resonant Capacitor Energy Converter 2(n-1) Switches, 2n Inductors Recharging Easy

14. CHARGE EQUALIZATION CIRCUIT

15. Voltage B1
Sense
Voltage B2
Gate Driving Signal Sense
Voltage B3
Sense
Signal
Voltage
Conditioning
Sense
B4
Voltage B5
Sense
Single Chip MUX
Processor ADC Voltage
B6
Sense
Voltage
Sense
B7
Voltage
Sense
B8
Voltage
Sense
B9
Voltage
Sense
B10
Voltage
Cr
Block diagram of control unit Sense

16. Start Charging
Wait for Tvdp
Read battery
voltage, Vn
Yes
For all n,
Terminate charging
Voltage Vn=Vfull
Detecting No
Phase 1 N
Vavg n 1
Vn
N
No For any n
Vn > V avg
Yes
Activate PWM module
n, calculate duty ratio
Reset ta
Charge
Balancing For activated modules, process
Phase PWM signals
Yes
ta < tcep
Control flow chart
No

17. SOFTWARES
• MATLAB
• Orcad
• EdSim51

18. PROJECT PLANNING
RESEARCH ACTIVITY JAN FEB MAR APR MAY JUN JUL AUG SEP DIS
Discuss FYP title with
supervisor
Title submission and
presentation
Literature review
Thesis dissertation 1
(Ch. 1, 2 and 3)
Project Simulation
Experimental setup
Experimental
implementation
Result discussion
Thesis dissertation 2
(Ch. 4, 5 and 6)
Report submission /
Final Presentation

19. ESTIMATED PROJECT COSTS
Components Price
Zivan NG1 Charger RM 1800
Charging Balancing Module RM 800
Others RM 500

20. THANK YOU