Smart Charging: System Design and Implementation for Interaction Between Plug-in Electric Vehicles and the Power Grid

Recent years have witnessed steady sales increase of electric and plug-in electric vehicles (PEVs). Stringent government regulations alongside persistent pressure from environmental groups will further increase the demand and sales of such vehicles. This trend might put pressure on the grid and local power distribution circuits and transformers. A sudden increase in power consumption, mainly caused by people charging their vehicles at the same time, and during the already peak load on the utility, may cause problems. These problems are mainly caused by the heavy demand on the local voltage transformers and the power sources. Power generation and distribution utilities may need to incur significant cost increases if this problem is not handled appropriately. In this paper, we present a novel design and implementation logic for a smart grid system that allows for dynamic interaction between electric/PEVs and the power grid. This smart and dynamic interaction will allow for safe and semi-stable load on the grid and thus minimizing the cost and preventing damage caused by the excessive loads. The complete system design is presented in this paper with emphasis on the developed algorithms. It has been implemented and tested on the Chrysler's PEV RAM 1500 U.S. Department of Energy pickup trucks.

I. Introduction

This paper presents and illustrates the system design and implementation of optimized charging (OC), also known as smart charging. OC tries to avoid an issue that could become critical as the number of electric and plug-in electric vehicles (PEVs) keep increasing [1]. Advancements in the lithium ion (Li-Ion) battery technology have also helped the increasing sale trends. These batteries require specific charging techniques [2], [3], [30]. Fig. 1 shows the current trend of PEV sales. This trend is expected to continue increasing [4].