Upload
others
View
5
Download
1
Embed Size (px)
Citation preview
##1
Individual Electro-Hydraulic Drives
for Off-Road Vehicles
(a DOE supported project)
Maha Fluid Power Research Center
Purdue University, West Lafayette, IN (USA)
https://engineering.purdue.edu/Maha/
Shaoyang Qu, Dr. Lizhi Shang
Prof. Sudhoff (co-PI) Uwe Neumann, Enrique Busquets Gary Kassen, Roman Plaszewski
PI: Prof. Andrea Vacca
##2Basic Idea
Electric – Hydraulic Hybrid
architecture
Main features
✓ Self contained individual drives
✓ No fluid throttling
✓ Energy recuperation
✓ Reduced ICE size
✓ Enables smart actuators, operating
as modern “plug & play” elements
✓ Zero emission modes
DOE Objective: Lower power
consumption of the fluid power
system up to 70%
##3Key components
P
Objective 1 (O1). 4-quadrant EH hydraulic unit
Objective 2 (O2). Individualized EH system
Objective 3 (O3). Technology demonstration
##4
4
• Baseline measurements
• Power consumption analysis
• Simulation model of mechanism
Reference vehicle
System configuration
EH unit optimization
(Baseline)
Contents
(Hydraulic circuit)
(Electric motor and pump)
##5
Off-road construction vehicle: skid-steer loader Case TV 380
boombucket
• Two functions (boom, bucket) considered for the technology demonstration
• Machine instrumented for baseline measurements of hydraulic power consumption
• Execution of test plan representative of typical machine duty cycle
Machine Main Specification
Engine TypeDiesel, Turbo – Direct
Injection,4 cylinders
Max power 90 hp [67 kW]
Fuel Capacity 25.5 gal [96.5 L]
Max Standard flow 24.2 gpm [91.5 L/min]
Machine Weight 10,207 lb. [4630 Kg]
Engine speed 1150-2500 rpm
Reference Vehicle
##6
Raise Lower Raise Lower
high load – low speed low load – high speed
𝐹𝑝1𝑝2
The reference machine is designed towards functionality and cost more than efficiency.
Reference Vehicle
Boom test
##7
Model of the hydraulic system
Model of the mechanism
Bucket
Boom
Tip Cylinder
Lift Cylinder
Simulation Method: Mechanism
Reference Vehicle
##8
Simulation Method: Mechanism
Reference Vehicle
##9
9
• Circuit configuration
• Evaluation of efficiencies
• Experimental set up
Reference vehicle
System configuration
EH unit optimization
(Baseline)
Contents
(Hydraulic circuit)
(Electric motor and pump)
##10
VALVES
ECU
VALVES
ECU
Boom control (EHA)
main control
unit
Operator interface
Energy StorageBattery
EngineGeneratorICE
External Grid
Bus
EHA Power Electronics
Bucket control (EHA)
DC Link Distribution
EHA Power Electronics
• EHA units are powered by a vehicle DC
power distribution network
Proposed architecture
##11
closed circuit option open circuit option
Proposed architecture
##12Results – Boom cycle
Remarks
✓ Closed vs open
circuit architecture
✓ Independence on load
##13
Raise boom Lower boomBucket
downBuc
up
Results – Boom/Bucket cycle
##14Energy Flow
ሶ𝑥𝐹
Raising phase
Accumulator power 𝑝𝑎𝑐𝑐
System efficiencyInput power
𝑝𝑖𝑛𝑝𝑢𝑡EH unit
power
𝑝𝐸𝐻
User power
𝑝𝑈𝑠𝑒𝑟
𝑝𝑢𝑠𝑒𝑟𝑝𝑖𝑛𝑝𝑢𝑡 + 𝑝𝑎𝑐𝑐
× 100%
Circuit efficiency𝑝𝑢𝑠𝑒𝑟
𝑝𝐸𝐻 + 𝑝𝑎𝑐𝑐× 100%
##15
Input power
𝑝𝑖𝑛𝑝𝑢𝑡 𝜔, 𝑇
Shaft power𝑝𝑠ℎ𝑎𝑓𝑡
Electric Motor efficiency
𝜂 𝜔, 𝑇 =𝑝𝑠ℎ𝑎𝑓𝑡
𝑝𝑖𝑛𝑝𝑢𝑡× 100%
EH unit power
𝑝𝐸𝐻
𝑝1
𝑝2
Pump efficiency
𝜂 𝑝2 − 𝑝1, 𝜔 = 𝜂𝑉 ∗ 𝜂ℎ𝑚 =𝑝𝐸𝐻𝑝𝑠ℎ𝑎𝑓𝑡
× 100%
Energy Flow
##16
• Raising with 1000lbs
• 4-quadrant pump, closed loop
• Average speed: 2867rpm
Motor&
Inverter
92.0%
6.04kW
Power
input
5.56kW
Shaft
Hydraulic
Pump
88.6%
Heat0.48kW
4.93kWCircuit
98.4%
Accumulator
0.08kWHeat &
Leakage0.63kW
Heat0.08kW
4.93kW
User
power
Power flow
##17
• Lowering with 1000lbs
• 2-quadrant pump, open loop
• Average speed: -3576rpm
Motor&
Inverter
91.8%
2.33kW
Power
Output
2.53kW
Shaft
Hydraulic
Pump
93.7%
Heat
2.71kWCircuit
98%
Heat &
Leakage
2.75kW
User power
Heat
0.2kW 0.18kW 0.04kW
Power flow
##18
• Building EHD with standard hydraulic components (later with new designed
DOE-Unit)
• Coupling force controlled cylinder drive (transmission ratio=1) for load
simulation
18
Test rig
##19
19
Test rig
Experimental set up
##20
20
• Hydraulic unit
• Electric machine
• Model integration & optimization
• Prototype
Reference vehicle
System configuration
EH unit optimization
(Baseline)
Contents
(Hydraulic circuit)
(Electric motor and pump)
##21
Fluid-Dynamic Module
-Analysis of Main Flow
-Effect of Porting grooves
-Aeration and Cavitation
Lateral Gap Module
Fluid Structure and
Thermal Interaction
Loading Module
Evaluation of
Instantaneous Radial
Forces and Torque
Journal Bearing
Module
Fluid Structure
Interaction
Micro-Motion Module
Evaluation of Gears’
Micro-Motion
Noise FEM/BEM Module
-Fluid-Borne Noise
-Structure-Borne Noise
-Air-Borne Noise
CAD Drawings
Geometrical Module
-Flexible geometry from CAD
-Asymmetric teeth
-Cycloidal-involute Profile
-Helical Gears
HYGESim (HYdraulic GEar machines Simulator)
Model integration – Hydraulic unit (O1)
##22Model integration – Hydraulic unit (O1)
Journal Bearing
Module
Fluid Structure
Interaction
Micro-Motion Module
Evaluation of Gears’
Micro-Motion
Lateral Gap Module
Fluid Structure and
Thermal Interaction
Coupled Lumped/Distributed param. modeling of:
• Inertial motion of floating elements
• Static cavitation
• Mixed Lubrication
• Elastic Body deformation
• Elastic Fluid-Structure Interaction
𝑀 =𝑑𝐻
𝑑𝑡 റ𝐹 = 𝑚
𝑑 റ𝑣
𝑑𝑡
ℎ = ℎ 𝑝, 𝑥, 𝑦, 𝑡
##23Model integration – Hydraulic unit (O1)
High Efficiency Piston PumpHigh efficient compact EHA
Variable Displacement External Gear Machine
##24Model integration – electric machine (O2)
Set of optimal design
solutions
Electric drive
performance
Mechanical output
Operating Conditions
Magnetic
Material Characterization
Winding Configuration
Vehicle power
requirements;
EHA requirements;
manufacturability constraints; …
Geometry
Candidate Create
feasible
geometry
Hydraulic
s
Mass,
volume, ...
Electric
Analysis
Magnetic
Analysis
Control
Leakage and
magnetizing
inductances,
Ohmic resistance,
proximity effect,…
Select current
commands,
winding and
semiconductor
losses, …
Core
losses,
torque, …
Electric Drive Optimization
##25EH unit optimization (O2)
NSGA-IIAlgorithm
InitialDOE
Gear & Groove
Parameters
GearGenerator
Gear calculation
Feasibility Checks
Geometrical Model
C++
Groove design
.txt files
Tooth profile
.txt files
Geometry files
.txt files
Rejected
Previous Optimization
Results
Post
Processing
Results files
.txt files
Design Grooves
##26
Elec
Mach
High Power DC
Distribution
Low Voltage
Control Power
Vehicle
CommunicationVehicle Safety
Cooling
Cooling
Power Electronic Inverter
Controller
6 Switch
Bridge
VALVES
ECU
VALVES
ECU
Boom control (EHA)
main control
unit
Operator interface
Energy StorageBattery
EngineGeneratorICE
External Grid
Bus
EHA Power Electronics
Bucket control (EHA)
DC Link Distribution
EHA Power Electronics
Electric system Architecture
##27Accomplishment
O1. EH unit
• 4-quadrant hydraulic unit design
• 4-quadrant electric motor design
• Performance evaluation of the EH unit
• EH unit Design integration
O2. EH module
• Modular simulation approach
• Duty cycle definition
• System configuration
• Circuit mode and control laws definition
O3. Technology Demonstration
• Baseline measurements
• Energy consumption analysis
• Simulation model of mechanism
##28
O1. EH unit
O2. EH module
• Thermal analysis and cooling solution
• Experimental validation of the functionality
• Controllability analysis and tests
O3. Technology Demonstration
• Configuration on the reference vehicle
• Supervisory controller for energy management
• Integration of energy generator and power electronics
Future work
O1. EH unit
• Design for manufacturing• Evaluation of Internal & external gear
machines
• Cooling solutions (fan, oil circulation)
• Structural analysis
##29
Thank you!
Question?