Direct power control of DSTATCOMs for voltage flicker mitigation

Distribution static synchronous compensators (DSTATCOMs) are a viable solution for improving power quality in distribution systems, including mitigation for temporary interruptions, voltage dips, harmonics and voltage flicker. Conventional DSTATCOMs are implemented using two cascaded loops, an AC current control loop and a DC-bus voltage loop. This paper proposes an alternative control structure based on the simultaneous control of line current and DC-link voltage by means of instantaneous power control. The instantaneous real and imaginary power calculation is derived and explained. Requirements for flicker and harmonic mitigation are identified. The controller is implemented using two hysteresis comparators and an optimum switching table. The features of the proposed technique are illustrated by means of simulation and experimental results. Advantages include a simple and robust control structure, and better tracking of load fluctuations and/or harmonics.