Energy Management of a Series Hybrid Electric Powertrain (this one)
1. Energy Management of a Series
Hybrid Electric Powertrain System
By: Saifuddin Abdul Halim (Mech Eng MEng)
Project Supervisor: Dr Saber Fallah
• Due to the increasing vehicle emissions, researchers and vehicle manufacturers
resorted to develop electric vehicle as an alternative.
• Disadvantages of EV results in the introduction of hybrid vehicle.
3. Why series HEV?
• Equivalent Consumption Minimization Strategy (ECMS) was originally
introduced by Paganelli et al., in 2002 for parallel configuration.
• Series HEV has a huge potential due to the downsizing of the engine as well
other factors such as the removal of gearbox, simplifying the configuration
reducing vehicle mass.
• Beneficial for urban-driving cycle.
4. What is ECMS?
• The basis of ECMS is that discharging of power from the battery at any instant
will results in equivalent fuel being consumed by the ICE to recharge the
in the future and vice versa.
• ECMS reduces the overall fuel consumption by minimizing the total equivalent
• The total fuel consumption is the sum of fuel consumed by the ICE to drive
motor via generator and the fuel consumed to recharge the battery.
𝐺𝑡 = ṁ𝐼𝐶𝐸 𝑃𝐼𝐶𝐸,𝑑𝑒𝑚 𝑡 + ṁ 𝐵𝑎𝑡𝑡,𝑒𝑞 𝑃𝐵𝑎𝑡𝑡 𝑡
𝑃𝐼𝐶𝐸,𝑑𝑒𝑚 𝑡 =
+ 𝑆𝑐ℎ𝑔 𝜂 𝑔𝑒𝑛 𝜂 𝐵𝑎𝑡𝑡 𝑃𝐼𝐶𝐸,𝑟𝑒𝑐ℎ𝑔(𝑡)
ṁ 𝐵𝑎𝑡𝑡,𝑒𝑞(𝑡) =
𝑆 𝑑𝑖𝑠 𝑃𝐵𝑎𝑡𝑡
𝜂 𝐵𝑎𝑡𝑡 𝐻𝐿𝐻𝑉
• Tendency of significant power source variation that leads to dramatic wheel-torque
• Possibility of delayed and hesitation of torque response / poor throttle response.
• In series HEV, these problems can be reduced due to having only one type of energy,
electrical energy, supplied to the EM and since the ICE is decoupled from the driving the
Modelling a conventional and a series hybrid powertrain.
Identifying and applying basic operating conditions.
To simulate the Equivalent Consumption Minimization Strategy (ECMS) control strategy.
Carrying out forward simulations for both models under two different driving conditions.
Comparing fuel economy as well as the velocity performance of both vehicles.
Optimizing the ECMS parameters to achieve a minimum of 15% reduction in fuel
9. ECMS controller & power distribution
Increase in Angular Speed
Decrease in Angular Speed
torque demand at EM via
+ve for driving or -ve for RBS
Calculation of Power
+ve for driving or
-ve for RBS
P(demand,EM)=P(ICE)+P(Battery) P(demand,EM) = P(Battery)
SoC ≥ SoC (max)SoC ≤ SoC (min) SoC (min) < SoC < SoC (max)
Determination of Fuel
Consumption using ICE fuel
12. Change in equivalency factor
The performance evaluated
• Overall fuel consumption at the end of the drive.
• Velocity trend of the vehicle.
Equivalency Factor, 𝑺 𝒅𝒊𝒔
The implementation of ECMS in series HEV managed to reduce fuel consumption up to
17.5% than the conventional vehicle under cruising mode and up to 28.3% under
Although fuel consumption is reduced, but the downsizing of engine in series HEV
means that the benefit is achieved at the expense of vehicle velocity.
ECMS controller also able to adapt to change in its own parameter.
In addition, the benefits of the ECMS are also transferable between configurations and
also driving conditions.