Energy Management System for LVDC Island Networks
Narayanan, Arun (2013)
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe2015111617194
https://urn.fi/URN:NBN:fi-fe2015111617194
Tiivistelmä
Recent developments in power electronics technology have made it possible to develop
competitive and reliable low-voltage DC (LVDC) distribution networks. Further,
islanded microgrids—isolated small-scale localized distribution networks—
have been proposed to reliably supply power using distributed generations. However,
islanded operations face many issues such as power quality, voltage regulation,
network stability, and protection. In this thesis, an energy management system
(EMS) that ensures efficient energy and power balancing and voltage regulation has
been proposed for an LVDC island network utilizing solar panels for electricity production
and lead-acid batteries for energy storage. The EMS uses the master/slave
method with robust communication infrastructure to control the production, storage,
and loads. The logical basis for the EMS operations has been established
by proposing functionalities of the network components as well as by defining appropriate
operation modes that encompass all situations. During loss-of-powersupply
periods, load prioritizations and disconnections are employed to maintain
the power supply to at least some loads. The proposed EMS ensures optimal energy
balance in the network. A sizing method based on discrete-event simulations has
also been proposed to obtain reliable capacities of the photovoltaic array and battery.
In addition, an algorithm to determine the number of hours of electric power
supply that can be guaranteed to the customers at any given location has been developed.
The successful performances of all the proposed algorithms have been
demonstrated by simulations.
competitive and reliable low-voltage DC (LVDC) distribution networks. Further,
islanded microgrids—isolated small-scale localized distribution networks—
have been proposed to reliably supply power using distributed generations. However,
islanded operations face many issues such as power quality, voltage regulation,
network stability, and protection. In this thesis, an energy management system
(EMS) that ensures efficient energy and power balancing and voltage regulation has
been proposed for an LVDC island network utilizing solar panels for electricity production
and lead-acid batteries for energy storage. The EMS uses the master/slave
method with robust communication infrastructure to control the production, storage,
and loads. The logical basis for the EMS operations has been established
by proposing functionalities of the network components as well as by defining appropriate
operation modes that encompass all situations. During loss-of-powersupply
periods, load prioritizations and disconnections are employed to maintain
the power supply to at least some loads. The proposed EMS ensures optimal energy
balance in the network. A sizing method based on discrete-event simulations has
also been proposed to obtain reliable capacities of the photovoltaic array and battery.
In addition, an algorithm to determine the number of hours of electric power
supply that can be guaranteed to the customers at any given location has been developed.
The successful performances of all the proposed algorithms have been
demonstrated by simulations.