Plug in Series Hybrid System

Traction Motor

Traction motor

Electric Motor

Power Converter

GeneratorI.C. Engine

Battery Storage

Charger

Drive Power Electric Power

Fig 1. Schematic of plug-in series HEV

Fig. 2 Prius series/parallel hybrid system

Fig. 3 This project - series hybrid system based on

modifying Prius

Generator Design Update

• Lower power (1kW) prototype machine has been fully constructed.

• Package is less than

6” in diameter

• Back-EMF waveforms are sinusoidal and

indicate a machine constant of 0.31 V/(rad/s).• Innovative drive is necessary to get

high stand-still torque AND high

speed operation.

Generator Design Update• Performance of 1kW prototype machine:

(a) (b)

(a) Torque (blue) curve as speed increases and (b) close up of the current waveform (pink)

• Operation of the prototype has been verified, so design of the 8kW starter-alternator has commenced

Energy Storage Simulation Initialization

BatterySpecific Energy

(Wh/kg)Useable

SOCηd ηc

Lithium Polymer

143 ~70% 95% 95%

NiMH 46 ~40% 84% 84%

Parameters of Li-Polymer and NiMH batteries

The test route around the city of Lincoln, NE

Mass mv

(lb)

Wheel dia.

(inch)fr CD

Af(m2)

2890 150.00

80.26 2.16

Relevant Vehicle Parameters

Driving speed schedule of vehicle

Changeable altitude of test road

Test Data

Energy Simulation ResultsBattery

TypeUseable

energy(kWh)

Capacity (kWh)

Weight (kg)

NiMH 3.07 7.68 167

Li-Polymer 2.54 3.63 26

Battery requirement for a 15 miles range

Battery transfer energy during drive

Li-Polymer battery output powerBattery SOC with changeable altitude and

constant altitude

1.High energy efficiency can reduce battery energy losses2.Maximize ΔSOC can dramatically reduce the total battery capacity requirement3.The potential energy change with altitude can’t be ignored in design

Conclusion: