New network structures of reconfigurable fractional-order PID regulators with DVCC

This brief paper shows design procedure towards new non-integer order proportional-integrative-derivative (PID) regulators with single grounded two-terminal device known as constant phase element (CPE). Proposed concept is based on the modified matrix method of unknown nodal voltages originally invented to analyze linearized lumped circuits. New topologies of PID regulators are obtained by handling with pseudo-admittance matrix prefilled by fixed connection of single differential voltage current conveyor (DVCC). Unique property of designed circuits is orthogonal electronical reconfiguration of the voltage transfer function by using external control quantities; this is achieved thanks to a suitable interconnection of several operational trans-admittance amplifiers (OTA). It is shown by using frequency- and time-domain Oread Pspice circuit simulations that network topologies provided in this manuscript allows smooth closed-loop feedback control dynamics. Limited validity of a passive ladder approximation of CPE together with the parasitic properties of DVCC as well as OTA causes limitations of regulator function; these aspects are theoretically analyzed. Finally, further practical perspectives in area of PID regulation are shortly discussed.