Abstract
This paper presents a novel frequency-domain approach
towards the control design for parallel grid-connected
voltage source inverters (VSIs) with LCL output filters. The
proposed method allows to design the controllers of multiple
VSIs in a single step, and inherently attenuates the resonances
introduced by the output filters and coupling effects while
guaranteeing stability. Performance specifications such as desired
closed-loop bandwidth, decoupling or robustness towards multimodel
uncertainty can be specified through frequency-domain
constraints. Furthermore, controllers can be designed in a plugand-
play fashion. The designed controllers are equivalent in
structure to multivariable PI controllers with filters. As the
control design is based on the frequency response of the system,
the algorithm is independent of the model order, which allows
the use of large and high-order models. The performance of the
method is demonstrated on a relevant example of a low-voltage
distribution grid with 5 VSIs, and the results are validated both
in numerical simulation using MATLAB/Simulink as well as in
power-hardware-in-the-loop experiments.
towards the control design for parallel grid-connected
voltage source inverters (VSIs) with LCL output filters. The
proposed method allows to design the controllers of multiple
VSIs in a single step, and inherently attenuates the resonances
introduced by the output filters and coupling effects while
guaranteeing stability. Performance specifications such as desired
closed-loop bandwidth, decoupling or robustness towards multimodel
uncertainty can be specified through frequency-domain
constraints. Furthermore, controllers can be designed in a plugand-
play fashion. The designed controllers are equivalent in
structure to multivariable PI controllers with filters. As the
control design is based on the frequency response of the system,
the algorithm is independent of the model order, which allows
the use of large and high-order models. The performance of the
method is demonstrated on a relevant example of a low-voltage
distribution grid with 5 VSIs, and the results are validated both
in numerical simulation using MATLAB/Simulink as well as in
power-hardware-in-the-loop experiments.