CHARGING OF PLUGIN ELECTRICAL VEHICLE

Task 4: Advanced managing strategies for multiple charging requests in an electrical grid (The “smart” approach).

In task 4, we analysed the effectiveness of smart strategies in which the charging processes of each user are scheduled on the basis of a more sophisticated priority criterion rather than simply considering only the arrival time, and the charging rate of each user is adapted to the grid load condition during the charging process.

We firstly considered the following priority and charging rate assignment functions:

The priority function (1) is formulated to assign priority to the users on the basis of both the amount of power required and the electricity rate they are disposed to pay. The influence of each of these aspects (power required and electricity rate) on determining the user priority can be adjusted by tuning the weighting coefficients a and b, with a+b=1.

The charging rate assignment function (2) consists in distributing the energy required by each user over the entire time period available before the user leaves the system.

Since the energy still required and the time available for each user change during the process, the implementation of the smart strategy requires a “frequent” communication about the user state of charge, and the updating of the priority and charging rate at regular intervals. The duration of these intervals is indicated as time resolution. In this task, we used a time resolution of 0.25 h. 

Task 5: try the effectiveness of your own advanced managing strategy.

In this task we carried out several simulations by introducing different smart strategies. In particular, we experimented different ways of assigning the priority of the users and different time resolution values. 

Task 6: Large scale scenario.

In this final task we evaluated the effectiveness of the different strategies previously analyzed in a large-scale scenario in which several grid nodes are considered. We considered different Uniform and Gaussian profiles for the electricity rate and the arrival and departure times of the users.