Content from this work may be used under the terms of the Creative Commons Attribution 0 licence

Parallel
: -The basic HEV powertrain consists of Electric motor, ICE, Generator, battery, power 
convertor and transmission. In the Parallel HEV the electric motor system and the ICE are arranged 
parallelly and both combines their power and drives the wheels. And this configuration is more efficient 
than the series HEV. It can also give instantaneous power during high performance requirements by 
electric motor assisting the ICE to build more power. But it requires a complex linkage between the 
engine and motor shaft to join and give combined power.
Series
: - In the series HEV the engine doesn’t have any mechanical linkage with the wheels, and they 
don’t have any transmission because the wheels are driven only by the motors. The engine is connected 
to the generator which generates the electricity then with help of charger it is stored into the battery, 
then from the battery the controllers supplies the current to the Electric Motor and which drives the 
wheels. the Series HEV can run on motor independently when the engine is Shut Off. The efficiency of 
the vehicle is less than the Parallel HEV due more no of components arranged in series HEV which 
increases the energy losses.
Power-Split
: - Basically it is combination of both the Series and Parallel HEV powertrain, the Power-
split HEV power train starts from the engine which produces the power from where it is divided in to 

---

2020 3rd International Conference On Green Energy And Environment Engineering
IOP Conf. Series: Earth and Environmental Science
633
(2021) 012007
IOP Publishing
doi:10.1088/1755-1315/633/1/012007
3
two paths where one goes directly to the transmission and drive the wheels like conventional vehicle 
whereas other goes is connected to the generator which generates electricity and stores in the battery 
and then later use it to drive the motor which is connected after the transmission directly to the driving 
shaft. So here both Series and Parallel concept is used for getting the best efficiency of the vehicle 
according to the driving conditions.
There are also other types of HEV on basis of power source mainly electric power source such as Full 
HEV, Mild HEV, Plug-in HEV, Micro-hybrid etc.