Battery Performance Verification In Marine Hybrid

Battery Performance Verification In
Marine Hybrid Applications
Dipl.-Ing. Tony Schröer1, Dipl.-Ing. Ralf Hecke2, Ralf Beckers3
Abstract
Electric Hybrid-Drive boats offer an exci ng new perspec ve on seafaring. Manoeuvring silently in the marina and enjoying extended
autonomy and comfort when mooring or anchoring at high seas while harves ng the power of the sun and the winds are no longer
science fic on. However, a highly sophis cated Energy Management System (EMS), a high power Energy DistribuƟon/DisconnecƟon
Unit (EDU), and a Lithium-Ion baƩery (LIB) are required to make it all happen and keep the vessel‘s vital systems safe, at all mes. The
complex interac on of all energy sources and sinks and the resul ng energy flows „seen“ by the LIB must be understood completely
during the design phase of the vessel. Digatron‘s Hardware-in-the-Loop (HiL) rig helps to cut R&D me and cost.
Grid ConnecƟon
Alternator
Solar Energy
Wind Energy
Energy
Unit · EDU
Energy
Management
System · EMS
with BMS
Hybrid Propulsion System
Crank BaƩery
24VDC Power Network 230VAC Power Network
In hybrid opera on there
are mul ple power sources
connected to the LIB such as
photovoltaic, wind energy,
sha alternator, and grid
connec on. At the same me
the EDU has to stabilize the
board net and to cover the
electrical loads. That requires
a close monitoring of the
ba ery.
HiL Setup
The interac on between
LIB, BMS, EDU, and
EMS can be tested in a
laboratory environment.
Digatron, shows how
their experimenta on
can enable new strategies
to improve charge
acceptance — not just
by changing ba ery
chemistry but also crea ng
energy management algorithms to increase ba ery performances
by tweaking the energy management algorithm.
To develop a source/sink scenario that stresses the ba ery similar
to the real opera on in the field a hardware in the loop (HIL) test
rig was developed combining the ba ery, its BMS and the energy
management algorithm to stress the ba ery in the laboratory to
determine the behaviour of the ba ery and system.
The test rig consists of two power circuitries. One circuit allows for
emula ng the various loads and a second circuit emulates the all
power sources. That set up does also allow for tes ng a possible
zero current control since sources and loads need to be connected
at the same me to sink simultaneously while sourcing current.
The BMS was connected via CAN to a simple PC running xPC Target
from the Mathworks. The xPC target pla orm also executed the
xPC Target
Digatron
Controller
Host PC
Energy
Management
Algorithm
Digatron BM4
xPC Target Host
LIN/CAN Master
Gateway IXXAT
Digatron
Power Circuit
Alternator Emulator
Digatron
Power Circuit
Load Emulator
management algorithm that is Digatron‘s controller and the xPC
target system to exchange signals like source/sink inhibi on and
DC link voltage set point are realized using CAN.
HIL Program Concept
Digatron BM4 program
scheduler was used to
program the me flow of
the individual load profiles
including the signals
required to interface with
xPC Target
executing
the energy management
EM Strategy
algorithm via CAN. The
CANGUI of the system
easily creates that link such
that the required signals to
disable sources or sinks could be used in the schedule editor. The
schedules wri en map the real world usage as close as possible
including vessel wake up and a er run phases that charge the
ba ery while docking in the marina.
HIL Program Concept
Digatron BM4
Trip Sequencer
set new load profile parameters
Electric Energy Backbone
• Unlock Vessel
• Vessel Wake Up
• Activate BMS communication
• Key Crank
• Actual Drive, dynamically
adjusted with inputs from
xPC Target
• Anchorage / Mooring Phase
• Actual Drive
• Dock Vessel / Key Off / Lock Vessel
• After Run
• Deactivate BMS communication
Power Mode, Anchorage / Mooring Phase,
Docking Phase
Voltage Set Point,
Source Sink Inhibitors
Simulated Load Profile
The adjacent graph displays
the recorded ba ery voltage
and the current during one
cycle. A er a significant
load event the ba ery’s
charge acceptance is high
and almost all regenera ve
energy available can be used
to recharge the ba ery. In
this example power sources
are limited to 100A (100A source and 50A load leaves 50A for the
ba ery charge) however, if the SOC is increasing further charge
is voltage limited since the charge acceptance is not allowing for
more current acceptance.
This is typical ba ery behaviour. In the cycle shown the charge
removed during the load phase can very easily be recharged,
however once that amount is recharged the ba ery’s charge
acceptance refuses the offered charge current.
Results: Detailed Energy Management Control Behavior
Pure Battery Power
Max. Alternator Supply
Zero Current Control
Conclusions
Closed loop tests on system level help to understand interac ons of all individual components in detail as they would behave in the
real hybrid vessel.
Results can be used to develop and refine accelerated component test procedures.
Tests can be used to fine tune energy management algorithm with direct feedback from BMS and LIB.
System tests in laboratory environments are reproducible and can be used to compare different combina ons of components (LIB,
BMS, Energy Management Algorithm)
Digatron equipment is a good choice for complex HIL tests with easy integra on via CAN (CANGUI) to other systems
1) Tony Schröer is V.P. Sales and can be reached at  tony.schroer@digatron.de
2) Ralf Hecke is Manager E-Mobility and can be reached at  ralf.hecke@digatron.de
3) Ralf Beckers is Marketing Manager and can be reached at ralf.beckers@digatron.de
Digatron Power Electronics GmbH, Tempelhofer Str. 12-14, 52068 Aachen, Germany