Faculty of Mechanical Engineering Chair Agricultural Systems and...
Transcript of Faculty of Mechanical Engineering Chair Agricultural Systems and...
Electrical drive train for combine headers
Elektrifiziertes Antriebssystem für Getreideschneidwerke
Steffen Wöbcke, Thomas Herlitzius
P. Hornberger, N. Michalke, F. Mörtl, M. Müller, U. Schuffenhauer, J. Seyfarth
Faculty of Mechanical Engineering Chair Agricultural Systems and Technology
VDI-MEG Kolloquium Mähdrescher, Hohenheim, 12./13.September 2013
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 2
I. Introduction and description of initial state
II. Objectives of electrifying a combine header
III. System design
IV. Benefits of electrified headers
V. Summary and outlook
Content
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 3
� requirements of global market are increasing productivity with decreasing harvesting costs and increasing profitableness
� in past meeting requirements by
� improving functionality
� increasing diesel engine power
� increasing harvesting ground speed
� increasing header width
proposition:
continuing increasing combine productivity by
� using function-specific, distributed, modular designed drives
� new drive concepts, optimized in available space, energy-efficiency
� automation of operating sequences
Introduction
image source: Zürn
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 4
Initial state
knife
lateral knives
feeder belts
reel
intake auger
image sources: ACGO, Claas, Geringhoff
main header assemblies� knife� intake auger� reel� feeder belts (optional)� lateral knives
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 5
� knife:� belt, gearbox with shafts or hydraulic motor, cutting width > 9 m: divided cutterbar with two-
sided drive, fixed speed� intake auger:
� chain or gearbox and overload clutch, one-sided drive, fixed speed� reel:
� hydraulic motor or belt variator, one-sided drive, variable speed� feeder belts (optional):
� chain, fixed speed� lateral knives:
� hydraulic, electrical or mechanical
Initial state
image sources: Claas, Geringhoff, Zürn
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 6
reel intake auger knife intake belts
variability of speed
available - - -
separate reversing
- - - -
adjustable torque limits
- - - -
sensor systemn [min -1], M [Nm]
- - - -
Objectives of electrifying combine headers
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 7
reel intake auger knife intake belts
variability of speed
available desired desired desired
separate reversing
desired desired - desired
adjustable torque limits
desired desired desired -
sensor systemn [min -1], M [Nm]
desired desired desired desired
Objectives of electrifying combine headers
� technical solution meeting demands best: electrical drives
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 8
experimental model: header Zürn 640 PF 40 ft (12 m)� knife:
� belt with planetary drive, two-sided drive, fixed speed� intake auger:
� chain drive and friction clutch, one-sided drive, fixed speed� reel:
� hydraulic motor, middle drive, variable speed� feeder belts:
� 8 belts� chain drive, one-sided drive, fixed speed
� lateral knives:� mechanical
drives in combine header
knife intake auger feeder belts lateral knivesreel
Experimental platform
image source: Zürn
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 9
component speed [min-1] torque [Nm] power [kW]
knife 600 250 15,7
reel 40 1500 6,3
intake belts 385 120 4,8
intake auger 260 1000 27,2
lateral knives 550 17 1
sum 55,0
Nominal power requirements40 ft header for dimensioning
image source: Zürn
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 10
closed system of generation, transformation, storage, transfer and management� standard connection to combine:
� drive shaft� electric / CANBUS
� own generator on header� DC link� own cooling circuit
Design of electrical system
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 11
electrical system on header
� voltage level 58 V DC in DC link (extra low voltage, below threshold of 60 V)
� advantages:
� no additional safety equipment required (e.g. insulation monitor)
� legal regulations: even no protection against creature contact necessary
� reduced effort for EMC
� disadvantage: higher dimension of cable cross-section
image source: Compact Dynamics
Design of electrical system
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 12
� knife:� divided cutterbar with 2 drives� variable speed
� intake auger:� two-sided drive, 2 electric motors� partly integrated in auger� variable speed
� reel:� one-sided drive, 1 electric motor� partly integrated in reel� variable speed
� feeder belts:� 8 belts� every belt with own electric motor� partly integrated between belts� variable speed
� lateral knives:� left and right side� mechanical drive� alternative electric motors
image source: Compact Dynamics
Design of electrical system
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 13
technical data of main usedelectric machine Dynax in header
inverter 3-phase inverter integrated
voltage DC 42 V – 58 V
power (continuous) 20 kW (at 58 VDC)
power (maximum) 25 kW (at 58 VDC)
torque 75 Nm (up to 3000 min-1)
maximum speed 10.000 min-1
cooling water / glycol
weight 14 kg
174 ∅ 250
242
speed [1/min]
torq
ue [N
m]
efficiency of motor and inverter
number of Dynax machines in header:� generators (3)� intake auger (2)� reel (1)� knife (2)
image source: Compact Dynamics
Design of electrical system
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 14
challenges of function-specific, distributed, modular designed drives� in comparison to all-mechanical drives specific loads become more important � removal of inertia� decoupling of diesel engine’s and combine’s inertia system
� linear sinusoidal trajectory of cutterbar and load cycle of electric motor� simulation provides conclusions for
� dimensioning and design of drive system� strategy for control� mechanical loads� power distribution
-1
-0,5
0
0,5
1
0,25 0,3 0,35 0,4 0,45 0,5
F*
/Fm
ax
, P*
/Pn
t in s
linear force and drive power
F, variant 1
P, variant 1
F, variant 2
P, variant 2
Design of electrical system
-1,0
-0,8
-0,6
-0,4
-0,2
0,0
0,2
0,4
0,6
0,8
1,0
0 10 20 30 40 50 60 70 80
stroke [mm ]
M/M
max
forward stroke - acceleration forward stroke - deceleration
return stroke - acceleration return stroke - deceleration
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 15
� additional benefit caused by advantages of electrical drives
� decentralized drives are mostly integrated into functional elements
� reduced space demands especially in side panel sections
� enhanced maneuverability at barriers and headland
� reduced crossing crop and reduced header losses
� advantages of electrical drives in headers:
� variable speed
� absolute value
� direction
� adjustable torque limits
� integrated measurement of current and voltage
� calculation of speed and torque possible
Benefits of electrified headers I
image source: Zürn
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 16
� homogenized crop flow in header and in combine
� increased feedrate of combine at constant loss level
� reduced cleaning and separation losses at constant feedrate
� generation of feedrate related signal for feedrate control of combine
� reduced wear and tear of drives and functional elements
� reduction of maintenance
� reduced costs
Benefits of electrified headers II
image source: Wikipedia
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 17
� opportunity of separate reversing functional elements
� fast removal of jamming crop
� reduced machine downtime and increased combine performance
� condition monitoring of functional elements
� generation of load cycles
� maintenance interval load-dependent instead of time-dependent
� reduction of maintenance
� reduced machine downtime
� reduced costs
Benefits of electrified headers III
image sources: Schumacher, agrartechnik-im-einsatz
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 18
new form of power-train management system
� semi-automated header functions
� reduced excessive demands of operator, especially
� homogenizing crop flow in header and in combine
� fast removal of jamming crop
Benefits of electrified headers IV
image source: John Deere
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 19
Challenges of electrified header
challenges of electrical drive system in combine headers
� costs of electrical drives
� complexity
� generating electrical energy
� EMC
� cooling system
� …
� dynamic loads
� reliability of electrical components in field
� …
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 20
� configuration of combine header with electrical drives
� generation of electrical energy with generators on header
� independent electrical and cooling system with same standard connection to combine as conventional headers
� drive train as decentralized architecture with torque and speed as degrees of freedom
� enhancement of functionality
� new strategies of power-train management system
� semi automated sequences possible
Summary
image source: Zürn
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 21
� currently experiments on test stand
� field tests in season 2014
� statements to technical feasibility and suitability of electrical drives in
combine headers in field
� determination of power requirements and power distribution with
available information as torque and speed
� load cycles can be deviated
� evaluation of additional benefit
� estimation of economic feasibility
Outlook
September 12, 2013 VDI-MEG Kolloquium Mähdrescher Slide 22
Thank you for
your attention!
website of project:
www.eharvest.eu