Recent Submissions

  • Interleaved boost converter for power tracking of solar PV arrays

    Simões, M. Godoy; Brandao, Danilo I.; Liquet, Carlos; Manzano, Fernando A.; Ramos, Lucas F.
    In this paper the advantages of an enhanced boost converter are utilized in a photovoltaic based energy system, in order to improve the efficiency and the output/input voltage gain. In addition, this circuit topology allows lower input current ripple than conventional single-switch DC/DC boost converters, increasing photovoltaic energy yield. The floating interleaved boost converter was modeled, and a linear feedback controller was discretized for use with an embedded microcontroller. This controller consisted of a decoupled dual loop control structure capable of interacting with a maximum power point tracking procedure. Two strategies for controlling the DC link voltage were evaluated and compared in simulation. Moreover, two maximum power point tracking techniques were also implemented and compared; their performances were evaluated by simulation as well as demonstrated by an experimental set-up. The results show that the addressed topology is very promising, with potential benefits for solar power applications.
  • Modeling a self-excited induction generator

    Simões, M. Godoy (Colorado School of Mines. Arthur Lakes Library, 2019-05)
    Induction machines have been widely used in power generation and other industrial applications for decades due to their numerous advantages like robust design and lower cost as compared to synchronous machines. When a standalone induction generator like in isolated wind farm and micro hydro is driven by a mechanical prime mover, the residual magnetism in the rotor of the machine induces an electro-magnetic field (EMF) in the stator windings at a frequency proportional to the rotor speed. This EMF is applied to the capacitors (cap-bank) connected to the stator terminals and causes reactive current to flow in the stator windings. The capbank provides necessary reactive power to run the generator as well as reactive power to the inductive loads connected to the generator. Multiple generators can be connected in parallel to increase reliability and to provide required power for increasing loads. This paper presents a PSIM simulation model of a self-excited induction generator (SEIG) using the well-known [alpha beta gamma] three axis model for induction machines (IM). Transient response of standalone generator, two SEIG generators connected in parallel, and SEIG connected to grid is also part of this study. This paper is expected to be a learning module for electrical engineering students to understand dynamics of the induction machines.