Reactive power and unbalance compensation using STATCOM with dissipativity-based control

The paper investigates the use of dissipativity-based control for voltage-s ourced inverters (VSI) utilized as reactive power and unbalance compensator s, e.g., Static synchronous compensator (STATCOM). The approach relies on a frequency domain modeling of system dynamics using positive sequence and n egative sequence dynamic components. Following the passivity-based procedur e, a family of controllers is obtained whose objective is to deal with unba lanced supply voltages, and to perform regulation of ac unbalanced currents . The proposed solution is relevant for high-power VSI inverters where, due to switching frequency limitations, conventional regulators do not have en ough bandwidth to achieve reference tracking. New controllers include adapt ive refinements to cope with parameter uncertainties, and stability and con vergence proofs are outlined in all cases. Finally, a series of simplificat ions and adjustments have been explored to reduce the adaptive controllers to PI structures in stationary frame coordinates. The simplified controller s are in a form suitable for implementation, and establish a downward compa tibility with standard industrial practice.