In this paper, a cost-effective finite-time settling current
control system for a utility-interactive three-phase voltage
source inverter system with an inductor–capacitor–inductor
(LCL)-type filter is originally designed and developed. The
discrete-time system equation of the LCL-type filter is first simply
derived in the α−β stationary reference frame. Then, the
finite time of a three-sampling-period settling control algorithm
is derived in the form of state feedback, whereas the required
numbers of sensors are reduced by introducing an identification
algorithm. Moreover, the implementation of the novel control
scheme achieves the time-optimum response of a 3-D controlled
variable in the LCL-type filter when damping the LC resonance
strongly. The effectiveness of the proposed finite-time settling
control algorithm is substantially confirmed by the simulation and
experimental results of inverter, static synchronous compensator,
and rectifier modes of operation.