A Comparative Study of DQ and CSD Methods for Voltage Regulation in DSTATCOM-Based SEIG Systems

Self-Excited Induction Generator (SEIG) plays an important role in independent power generation systems. Since SEIGs have difficulty maintaining the terminal voltage when load conditions change, an adequate compensation and control system is required. Distribution Static Compensators (DSTATCOMs) stand out with their fast dynamic response, reactive power support, and harmonic reduction capabilities. The performance of DSTATCOMs depends on the effectiveness of the control method. In this study, the performance of the widely used dq method and Current Synchronous Detection (CSD) method is compared under nonlinear loads, unbalanced loads, and DC offset conditions. The CSD method stands out with its effectiveness in filtering PCC voltages, peak estimation, and simple structure. The dq method, thanks to its high accuracy and stability in phase synchronization, has provided successful performance in harmonic suppression, current and voltage balancing, and reduction of DC offset effects. In both methods, the total harmonic distortion (THD) of SEIG current and voltage is below 5% in accordance with IEEE-519 standards.