DSTATCOM Effect on the Adjustable Speed Drive Stability Boundaries

In this paper, the dynamic models for adjustable speed drive (ASD) and distribution-static compensator (DSTATCOM) are presented. An eigen domain approach to the transient response investigation is formulated by means of dqo variable in synchronously rotating reference frame to study the dynamic interactions between ASDs and DSTATCOM. Two inverter topologies of ASD, current source inverter and voltage source inverter, are included in the study as well as two control techniques of the DSTATCOM, namely voltage and current control. The study shows that the voltage control DSTATCOM improves the stability boundaries of the ASD utilizing either current or voltage source inverters, while the current control DSTATCOM has minor influence. In addition, the system dynamics show less sensitivity to the dc link capacitance for the voltage control DSTATCOM. These results are supported by analytical study of the characteristic equation of both the voltage and the current control DSTATCOM