Hybrid Electric Vehicles, 2nd Edition

11Electric Energy Sources and Storage Devices

11.1 Introduction

Energizing an HEV or EV needs basically two types of devices. The first device is an energy source, or more appropriately, a source of power. Examples of these are an ICE, and a fuel cell. The ICE converts chemical energy to mechanical energy, but since this device was discussed earlier in this book, it will not be discussed here. This chapter will, instead focus on electrical sources. In this category is the fuel cell, which directly converts chemical energy into electrical energy. The other devices that do not convert power, but rather store energy, are devices like batteries, ultracapacitors or supercapacitors, and flywheels. Such devices are appropriate for EV, HEV, or PHEV (plug‐in hybrid). Normally, in an HEV or PHEV, batteries or ultracapacitors can be charged by using the ICE, which can run a generator, and charge a battery or ultracapacitor. In case of an EV or PHEV, generally these will be charged from the utility power grid. Power sources noted above, or energy storage elements, can then drive an electric motor and provide propulsion. But energy storage systems offer the benefit of recuperating regenerative braking energy and store it for future use, normally to provide propulsion, thus leading to increased vehicle efficiency. In this chapter, modeling and simulation techniques will also be discussed to some extent, along with battery management and control, and we will discuss ultracapacitor applications ...