Dynamical performance of a single-phase thyristor a.c. regulator

The operation of a single-phase thyristor a.c. regulator is described in which thyristors are used to connect windings on a multiwinding transformer, so as to vary the amplitude of the regulator´s output voltage. Independent control of the amplitude of either the positive or negative halfcycles of the output voltage allows the regulator to be considered as a 2-variable system. Minimum response can be achieved with the use of a controller which is time shared between subsystems, but this produces interaction between them. Time-series methods are used to identify the regulator when it is operated under these conditions and the system´s stability bounds and decoupling conditions are defined. The regulator is decoupled to set-point input signals and output disturbances using state variable feedback and a `deadbeat¿ response in one cycle of the supply frequency is achieved.