IEEE Electrification Magazine - June 2014 - 37

Turbo
After Treatment
Engine
Shaft Output
Power

Motor/
Generator

Turbo
Generator

Inverter

dc Vehicle Power Bus

Propulsion
Drives

A/C

Fans

Pumps

Figure 8. The John Deere 644K hybrid loader.

Figure 9. The system architecture of turbocompounding.

be easier and worthwhile to take advantage of electric turbocompounding, which utilizes the waste heat discharged
through the tail pipe and is touted to boost vehicle efficiency, resulting in an increased fuel economy. turbocompounding is a topic of significant interest, and Bowman
Power from the United Kingdom is currently involved in
developing parts and systems for electric turbocompounding. John Deere had a Department of energy-funded project
to carry out research and development work in the area
of turbocompounding. a system concept diagram of the
turbocompounding for off-highway vehicles is shown in Figure 9. it can be seen in
Figure 9 that power electronics plays a
vital role for the successful implementation of electric turbocompounding.

technology. some key advantages of turf-care vehicle electrification are stated here and are also available online:
xx
the elimination of 102 hydraulic leak points in the reel
circuit
xx
a consistent frequency of clip that can only be generated by electricity
xx
reduced fuel consumption and sound levels
xx
easier maintenance than conventional mowers.
in conventional turf-care vehicles, 90% of all hydraulic
leaks occur in the reel hydraulic circuit, mainly due to the
need to have flexible hoses extending
from the front of the turf-care machine
for front reels. these hoses see a lot of
flexing during the mowing day as cutting units are raised and lowered. the
cutting units also steer and float to follow undulations, increasing the fatigue
for the reel motor hoses. the 2500e
e-cut hybrid riding Greens Mower has
eliminated 102 potential leak points by
removing all hydraulics from the cutting unit drive circuit. the electrification of green mower vehicles has
resulted in significant simplifications due to the elimination of the following components:
1) reel drive section of hydraulic triple pump
2) hydraulic reel motors
3) backlapping valve
4) hydraulic oil cooler
5) flexile hoses
6) fittings
7) hard lines.
Fewer hydraulic components leads to fewer leaks,
increasing the confidence that the finely manicured turf
will not be damaged by hot hydraulic oil spilled onto the
playing surface before an important tournament.

Class B Family of Inverters for
Vehicle Electrification Programs

The WBG devicebased systems offer
increased efficiency
in the vehicle,
resulting in reduced
fuel consumption.

the power electronics products manufactured and commercialized by JDes
for various vehicle electrification programs have been quite successful and
have received encouraging and outstanding reviews from the customers engaged in vehicle
platform integration. these inverters are the power drive
(PD) 550, the PD 300, the 644K hybrid dual inverter, the 944
hybrid inverter, and the reel motor controller inverter for turf
and utility vehicles. the class B PDs designed and manufactured by JDes are depicted in Figures 10 and 11; these are the
PD 550 inverter and PD 300 inverter.

Electrified Platforms for
John Deere Turf-Care Applications
three commercialized vehicle platforms for green mowers
for turf-care applications are briefly described here. some
key motivation behind the electrification of John Deere's
turf-care products is driven by the objective stating that
"nothing on your course gets more scrutiny than the
greens." this is why, since 2005, John Deere has been introducing customers to the many benefits of e-cut hybrid

7500/8500 E-Cut Hybrid Mower
no fairway mowers generate more confidence than the John
Deere e-cut hybrid models, such as the 2500e e-cut hybrid

IEEE Electrific ation Magazine / j une 2 0 1 4

Table of Contents for the Digital Edition of IEEE Electrification Magazine - June 2014