Nonlinear Control of Back-to-Back VSC-HVDC System via Command-Filter Backstepping

Figure 6

Three-phase AC-side currents via command-filter backstepping controller.

(a) Three-phase AC-side currents of AC system 1

(b) Three-phase AC-side currents of AC system 2

(c) Detail of three-phase AC-side currents of AC system 1

(d) Detail of three-phase AC-side currents of AC system 2