Abstract
A microgrid including distributed generators can operate connected to the main electrical network or in an isolated manner, referred to as island operation. The transition between both states can occur voluntarily, but a disconnection can also happen unexpectedly. The associated transients can be harmful to the grid, and compensating actions must be triggered to avoid service interruption, preserve power quality, and minimize the possibility of faults; island detection methods are essential to this end. Such techniques typically depend on communication networks or on the introduction of minor electrical disturbances to identify and broadcast unexpected islanding events. However, local energy resources are distributed, variable, and are expected to be integrated in a plug-and-play manner; then, conventional island detection strategies can be ineffective as they rely on specific infrastructure. To overcome those problems, this work proposes a straightforward, distributed island detection technique only relying on local electrical measurements, available at the output of each generating unit. The proposed method is based on the estimated power-frequency ratio, associated with the stiffness of the grid. A “stiffness change” effectively reveals island operating conditions, discards heavy load variations, and enables independent (distributed) operation. The proposal was validated through digital simulations and an experimental test-bed. Results showed that the proposed technique can effectively detect island operation at each generating unit interacting in the microgrid. Moreover, it was about three times faster than other reported techniques.
Highlights
The integration of alternative generation sources at the power grid’s distribution level has led to new challenges in the control, communication, and management areas of the electrical network
A microgrid is a cluster of distributed generation units (DGU) with power management and regulation capabilities that cover a local power demand [1,2]
Microgrids add flexibility since their operation is not restricted to a permanent connection to the main power grid; they can act independently in what is known as island operation
Summary
The integration of alternative generation sources at the power grid’s distribution level has led to new challenges in the control, communication, and management areas of the electrical network. The presence of externally introduced frequency drifts can cause false detection signals and a communication infrastructure is needed to gather the actual power demand To minimize these shortcomings, hybrid detection methods (HDM) were proposed, commonly classified as series or parallel. DGUs are expected to operate independently within a microgrid under a distributed approach Their management is desired to be decentralized, not relying on a communication layer or a central controller. The proposal does not imply adding devices but adding a software module to the DGU controller, avoiding increased costs or maintenance Such a distributed approach eradicates the need for communicating a tripping signal, as each generating unit would make the same detection independently. 140 ms 2.56 ms 300 ms 200~300 ms Simulation Validation yes yes yes yes yes yes yes yes yes yes Experimental Validation
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
