Modeling and Simulation of Variable Limits on Conditional Anti-Windup PI Controllers for VSC-Based Devices

This work focuses on variable limits of conditional anti-windup PI-controller described in the IEEE Std. 421.5-2016 applied in the current limiters of VSC-based applications. To overcome deadlock and chattering during numerical simulation of the Std. conditional anti-windup with variable limits, it proposes a method for software implementation based on Filippov theory. The robustness of the proposed implementation is studied through a VSC-HVDC link included in the WSCC 9-bus system and through STATCOM included in the Nordic-32 system. The case studies compare wind up, back calculation type anti-windup and heuristic methods applied in the conditional anti-windup with the proposed solution.