Tesis
Contribuição às estratégias de controle para sistemas distribuídos de potência
Fecha
2013-07-31Registro en:
OBERTO, Victor Paula. Contribution to the control strategies for distributed power systems. 2013. 134 f. Dissertação (Mestrado em Engenharia Elétrica) - Universidade Federal de Santa Maria, Santa Maria, 2013.
Autor
Oberto, Victor Paula
Institución
Resumen
A distributed power supply composed of multiple DC-DC converters connected in parallel offers several advantages in comparison to a centralized solution. Among these benefits are the following: redundancy, system modularity, increased reliability, improved thermal ow on the system and reduction in the physical size of the units. Its main purpose is to evenly share the output current between the converters. In practice, this specification
is rarely achieved without the use of a specific control strategy for sharing, since each
converter produces output dependent on the tolerances of the components and the line
impedance that connects the unit to the load bus. This imbalance in the shared current
can cause excessive stress on the units operating outside of their specifications, increasing
their chances of failure. Also, it is desirable that any points of failure are minimized or
eliminated by adopting a decentralized control strategy, minimizing connections between
units. In this work, the generalized model of output current for a i -th converter from a
source with n converters connected in parallel is obtained. To obtain this model, each
converter present in the system is modeled as a controlled voltage source, connected to the
load bus through an individual line resistance. As the main contribution, two strategies
to control current sharing between converters are proposed, based on parallelism without
communication between modules, specifically the droop control. To validate the design,
the simulation results for a power supply containing three converters in parallel applied
to a LED street lamp fixture are shown and analyzed. At the end of this document, the
conclusions and suggestions for future work involving the subject are developed.