BARRETO NETO, A. G. S.; http://lattes.cnpq.br/8808413435102315; BARRETO NETO, Arlindo Garcia de Sá.
Resumo:
This work studies the design of the control system of an experimental platform based
on a Peltier device that is employed a heat pump. Such platform has been developed to
simplify the characterization of thermo-resistive sensors by providing controlled heating
and cooling of the device under test through the control of the value and the rate of change
of the Peltier supply current. The Peltier device exhibits a non-linear behavior and thus
in order to design the control system of the platform (thermal chamber, Peltier module
and heat-sink) i t is required to study a non-linear model derived from thermodynamic
heat exchange equations. The proposed modeling approach is based on an input/output
model in which parametric identification techniques are employed to find the values of the
parameters of a discrete-time model. The identification experiments were carried out for
an operating region where the Peltier supply current varies from [—3, +3]A in steps of
0.5A The parameters of the discret-time model were obtained for such operating region
via polynomial interpolation. Based on such non-linear discrete-time model control laws
to track different temperature reference profiles can designed. Pole placement technique
was employed in the controller design. Consequently, to provide the same transient and
dynamic performance in closed-loop, the control law must also vary with the Peltier supply
current. The experimental results obtained with a laboratory prototype demonstrate the
feasibility of the proposed test platform.