IEEE Electrification Magazine - December 2019 - 97

the supervisory controller. In this experiment, the real
load profile based on a tugboat operation is emulated by
the eddy current brake loads and is used as a case study
to test the power and energy management system. Figure 9(a) demonstrates the battery used to serve the load
while maintaining the dc bus voltage. Based on Figure 9(b), there is a change of power dispatch between
DG and battery to serve the load. At a lower load
demand, the battery will be used to serve the load. The
onboard battery charging by DG is also demonstrated.
At this point, the battery will be charged so that the
load on the generator can be increased to prevent the
generator from operating under low-load conditions. DG
can be adjusted to the optimal operating point by
adjusting the charging power of the battery. Figure 9(c)
indicates the power sharing between DG and battery to
serve the load. In this case, droop mode power sharing
is demonstrated where dc voltage drops within 6% and
the voltage of dc bus is maintained at 550-570 Vdc.

Conclusions
Onboard hybrid power systems with low-emission energy
carriers are a promising solution for green shipping, replacing conventional diesel engine-based energy systems. However, there are several existing challenges related to these
new low-emission energy solutions that need to be investigated. A full-scale infrastructure for testing and verification
of such systems is one of the important stepping stones
while developing a reliable system. In this article, hybrid
power systems for ships and the related controllers were
discussed with a focus on the HPS Laboratory at NTNU as
an infrastructure for the testing and verification of shipboard dc power systems. A hierarchical control architecture
for the power and energy management of the hybrid power
system was also detailed. The experimental verification of
the energy management system for both the zero-emission
and hybrid propulsion mode along with voltage droop power-sharing using the real ship load profile was presented.
The HPS laboratory can effectively contribute to the
research and development of zero-emission shipping
solutions through the development of energy- and emission-management systems for hybrid power systems and
technology development of shipboard microgrids. Moreover, the lab infrastructure could accommodate the development of new control strategies and perform
hardware-in-the-loop testing under the operating conditions of the actual ship operation. Various real-field tests
can also be conducted on the laboratory setup based on
the real case mission profile, including the battery systems, supercapacitors, and fuel cells.

For Further Reading
J. M. Guerrero et al., "Shipboard microgrids: Maritime Islanded
power systems technologies," in Proc. PCIM Asia, June 2016, pp.
28-30.

N. P. Reddy, D. Pasdeloup, M. K. Zadeh, and R. Skjetne, "An
intelligent power and energy management system for fuel
cell/battery hybrid electric vehicle using reinforcement learning," in Proc. 2019 IEEE Transportation Electrification Conf. and
Expo (ITEC), pp. 1-6.
D. Park and M. K. Zadeh, "Dynamic modeling and stability
analysis of onboard DC power system for hybrid electric
ships," in Proc. 2019 IEEE Transportation Electrification Conf. and
Expo (ITEC), pp. 1-6.
M. Bin Othman Marzuki, A. Anvari-Moghaddam, N. Baizura Binti Ahamad, C.-L. Su, and J. M. Guerrero, "Scheduling of
power generation in hybrid shipboard microgrids with energy
storage systems," in Proc. IEEE 18th Int. Conf. Environment and
Electrical Engineering and 2nd Industrial and Commercial Power
Systems Europe, 2018, pp. 1-6.
M. K. Zadeh, L.-M. Saublet, R. Gavagsaz-Ghoachani, S.
Pierfederici, B. Nahid-Mobarakeh, and M. Molinas, "Energy
management and stabilization of a hybrid DC microgrid
for transportation applications," in Proc. IEEE Applied Power
Electronics Conf. and Exposition (APEC'16), 2016. doi: 10.1109/
APEC.2016.7468355.
M. K. Zadeh, B. Zahedi, M. Molinas, and L. E. Norum,
"Centralized stabilizer for marine DC microgrid," in Proc.
Industrial Electron. Conf. (IECON'13), 2013. doi: 10.1109/
IECON.2013.6699667.
DieselNet, "IMO marine engine regulations," Oct. 2016.
Accessed on: April 2, 2018. [Online]. Available: https://www
.dieselnet.com/standards/inter/imo.php
L. W. Y. Chua, T. TjahJowidodo, G. G. L. Seet, and R. Chan,
"Implementation of optimization-based power management
for all-electric hybrid vessels," IEEE Access, vol. 6, pp. 74,339-
74,354, Nov. 2018. doi: 10.1109/ACCESS.2018.2883324.
A. J. Sorensen et al., "Toward safer, smarter, and greener
ships: Using hybrid marine power plants," IEEE Electrification
Mag., vol. 5, no. 3, pp. 68-73, Sept. 2017. doi: 10.1109/
MELE.2017.2718861.

Biographies
Muzaidi B. Othman (muzaidi@unimap.edu.my) is with
the School of Electrical System Engineering, University of
Malaysia Perlis.
Namireddy Praveen Reddy (namireddy.p.reddy@ntnu
.no) is with the Department of Marine Technology, Norwegian University of Science and Technology, Trondheim,
Norway.
Pramod Ghimire (pramod.ghimire@ntnu.no) is with the
Department of Marine Technology, Norwegian University
of Science and Technology, Trondheim, Norway.
Mehdi Karbalaye Zadeh (mehdi.zadeh@ntnu.no) is
with the Department of Marine Technology, Norwegian University of Science and Technology, Trondheim,
Norway.
Amjad Anvari-Moghaddam (aam@et.aau.dk) is with
the Department of Energy Technology, Aalborg University,
Denmark.
Josep M. Guerrero (joz@et.aau.dk) is with the
Department of Energy Technology, Aalborg University,
Denmark.

IEEE Elec trific ation Magazine / D EC EM BE R 2 0 1 9

http://www.dieselnet.com/standards/inter/imo.php http://www.dieselnet.com/standards/inter/imo.php

IEEE Electrification Magazine - December 2019

Table of Contents for the Digital Edition of IEEE Electrification Magazine - December 2019