Control Strategy
This section describes the proposed control strategy for the
three current sources shown in Fig. 3. Our approach is to control
the currents is1 and is2 through the two inductors in Fig. 9.
The control diagram of the system is shown in Fig. 10. Similar
to active power filter control, a simple proportional controller
is used to act on the error between the references is1_ref and
is2_ref and the inductor currents is1 and is2.
The current references for the two inductors is1_ref and
is2_ref are made up of three components. The first component
ensures the tracking of the triangular reference. The desired triangular
references irec1_ref and irec2_ref are generated by multiplying
the averaged rectifier output current (Irec1 and Irec2)
and the triangular reference which is synchronized with the
line voltage. The dynamics of the averaging can be fairly slow,
since the result of a mismatch between the estimated and actual
values of IL simply results in real power injection/absorption
by current source into the load during the transient. The second