HEV( Hybrid Electric Vehicle)

Engine power train controls

Engine/powertrain controls for HEV (Hybrid Electric Vehicle)

·         This is a guideline for the students of Mechanical Engineering and Electrical Engineering.

·         Top 3 things to know are Model-Based development and simulation, HEV architecture (related to control systems) and Powertrain controls (related to control systems.)

·         Model-based development is the method of software development similar as of mathematical models (Just like flow charts)

·         Its practical use is in simulation, modelling related to physics (development of vehicle), and development and analyzing the complex control systems.

·         Model-based development is important for the control systems.

·         Example of model-based development: - The time required for the engine to reach from 0-60mph? Longitudinal vehicle dynamics (LVD) model and performance parameter (Speed Load Map) (forces required for the engine) is required. In the end, simulation of all three parameters is required to find out the answer. For the calculation of all three, it will take time in a manual way. Hence the model-based development is required.

·         Model-based development is used in the ABS system.

·         Knowledge of Longitudinal Vehicle Dynamics is required to create the LVD model for various purposes.

·         WOT and drive cycle performance is calculated by simulation of the engine with various performance models.

·         Later, the same LVD models are used to calculate the performance of 3 different hybrid structures.

·          Vehicle which has two or more energy conversion technologies having combination with one or more energy units is Hybrid Electric Vehicle.

·         Vehicles having the IC engine and Electric motor are the common type of HEV.

Limitation of I.C Engine:

·         They are the cause of the highest pollution.

·         There use fossil fuels.

·         No other alternative fuel is available for IC Engine vehicles.

·         Low peak efficiency (36% of Petrol Engine and 45% of Diesel Engine)

·         Lots of energy is wasting in the braking system.

·         Performance limitation (Engines torque at zero speed is zero. Other hand electric motors provide maximum torque when the engine speed is zero). The vehicle is required with the highest attractive force at zero speed.

Advantages of Hybrid Electric Vehicle

·         Highest efficiency

·         Regenerative braking (Energy required for braking is stored in the electric battery)

·         It provides the highest performance (Electric drive can provide the traction when the vehicle is not running)

·         Controls the emission.