Compared with the conventional active power filter
(APF), the static var compensator coupling hybrid active power
filter (SVC-HAPF) has distinct characteristics of low DC-link
operating voltage, which can lower the system and operational
costs. It also has a wider operational range than the conventional
hybrid active power filter (HAPF). In this paper, a harmonic
state-space (HSS) modeling is firstly proposed to address the
nonlinearity issue of the SVC-HAPF. The HSS based SVC-HAPF
model is linear time-invariant (LTI), which enables the optimal
control techniques. Then, the linear matrix inequality (LMI) based
H∞ optimal control design is proposed, which finds the optimal
controller parameters via convex optimization algorithm. The
proposed controller for the SVC-HAPF achieves high steady-state
accuracy, fast transient response, and fixed switching frequency
simultaneously. Finally, simulation and experimental results are
also provided to verify the effectiveness and performance of the
optimal controller for the SVC-HAPF in comparison with the recent
developed state-of-the-art multi-quasi-proportional-resonant
(MQPR) controller, which shows superior control performances.