Average Power Balancing Control of a STATCOM Based on the Cascaded H-Bridge PWM Converter With Star Configuration

This paper presents the average power balancing (APB) control method for the modular multilevel cascaded converter based on single-star bridge cells in the static synchronous compensator applications. The proposed control method accomplishes both the reactive power compensation and the dc bus voltage balancing control even under grid voltage sags. The low-voltage ride-through capability of the proposed method will become more and more important as more distributed generation resources are integrated into the grid. Laboratory test results are provided to validate the proposed APB control method.