Secondary Control for Storage Power Converters in Isolated Nanogrids to Allow Peer-to-Peer Power Sharing

It is usual in literature that power sharing among grid-forming sources of an isolated microgrid obeys their energy rating, instead of economic agreements between stakeholders, and circulating energy among them is usually avoided. However, these energy interchanges make strong sense and classical power sharing methods must be reformulated in the context of prosumer-based microgrids. This paper proposes a secondary control method for a prosumer-based low-voltage nanogrid that allows for energy interchange between prosumers, where storage systems, together with PV generators, are the controllable grid-forming sources. A power flow technique adapted to islanded microgrids is used for secondary control algorithm and the whole hierarchical control strategy for the prosumer converter is simulated and validated. This hierarchical control consists of three stages: tertiary control plans the energy interchange among prosumers, secondary obtains different voltage and power setpoints for each of the grid-forming sources, and, finally, primary control guarantees stable voltage and frequency values within the nanogrid with droop rules. Inner control loops for the power converter are also defined to track setpoints and assure stable performance. Simulation tests are carried out, which prove the stability of the proposed methods and the accuracy of the setpoint tracking.

THE BLUES AND OLDER MINORITY MUSICIANS: MORE THAN JUST MUSIC XXVI

This 26th annual symposium again showcases a world-wide musical genre in a regional setting with local performers. Texas Blues has emanated from a pantheon of talented artists beginning in the earliest days of Roots and Blues music to the present day, and Austin has become the epicenter of this talent and music. With legendary classic blues musicians from the early 2oth century to emerging younger musicians who re-energize and re-invent this uniquely American musical genre, to legendary music labels and venues like Antone’s which continue to engage blues music artists of all ages, Austin continues to be the home of Texas Blues. Lifetime Achievement Award -winning 89-year-young, Miss Lavelle White epitomizes the resilience and energy interchange of both the performer and the music, and their mutual contribution to longevity and continued engagement. Still performing after 70 years, she has influenced generations of younger prominent blues performers and continues to appear weekly at local blues mecca Antone’s along with her Grammy Award winning band and is preparing her fourth album release. This session will celebrate her music, her artistry, and her continued success as an older blues performer. A visit to a local blues venue later in the evening will allow for a true appreciation of the blues music scene in Austin.

Modeling and analysis of piezoelectric cantilever-pendulum system for multi-directional energy harvesting

Piezoelectric cantilevers are widely used in vibration energy harvesting. Simple cantilever-based harvesters are mostly unidirectional. In this article, we develop a cantilever-pendulum system that can harvest vibratory energy of excitations from an arbitrary direction. The new design consists of a traditional piezoelectric cantilever with a pendulum attached to the tip. It is shown analytically and experimentally that with proper parametric combination this system can induce modal energy interchange between beam vibration and pendulum motions due to 1:2 internal resonance, which ultimately yields multi-directional energy harvesting by a single cantilever. The underlying mechanisms of this design are analyzed in detail.