Improved Integral Anti‐Saturation‐Based Grid‐Connected Performance Method and Optimized DC Voltage Control for Grid‐Forming SVG

The large‐scale integration of renewable energy sources (RES), such as wind and photovoltaic power, has intensified transient overvoltage problems at the sending end of RES. These over voltages are mainly caused by short‐circuit faults and power fluctuations. The grid‐forming static var generator (GFSVG) has emerged as an effective solution due to its active voltage support capability. However, existing GFSVGs still face challenges in grid‐connected performance and DC voltage stability control. A major issue lies in the three independent phase clusters of the GFSVG, which impose strict requirements on phase voltage balancing. Zero‐sequence voltage superposition is a widely adopted method to achieve phase‐cluster voltage balancing, but the need for indirect active power calculation makes the control algorithm complex and increases the difficulty of the controller design. Another challenge concerns grid‐connected performance. Conventional methods lack an integral output dynamic limiting mechanism, which leads to prolonged over‐limit operation of the SVG. This causes rapid junction temperature rises in IGBTs, followed by protective shutdowns that threaten device reliability and system security. To overcome these challenges, this study establishes a direct linear correlation between the DC form of zero‐sequence voltage and the phase‐cluster voltage deviation. Based on this correlation, an optimized GFSVG phase‐voltage balancing control strategy using zero‐sequence voltage superposition is proposed. In addition, a novel GFSVG control method is introduced, which suppresses integral windup, eliminates power counter‐regulation and preserves equipment safety margins. The proposed strategies enable reliable control of complex transient voltage scenarios in RES‐dominated grids. Comprehensive simulations and experimental results confirm the effectiveness of the methods.