Improved HVDC Reactive Power Control Using Fuzzy PI

With the growing use of alternate power generation sources such as wind and solar, HVDC systems are an important enabler for power distribution between grids and enable a range of alternate sources connecting to the grid. Unlike AC systems, the HVDC system does not suffer from reactive power losses providing greater efficiency for power transmission. Minimizing reactive power, therefore, increases efficiency. However, in a transmission system, reactive power is useful in maintaining a stable voltage and improving fault recovery within the system. Due to DC transmission requiring the use of power electronics, especially in the area of Voltage Source Converters (VSC) HVDC converters, the controllability of DC allows for full control over the transmitted active and reactive power independently. In this paper, combining the fast responsive nature of the PI controller with the robust damping capabilities of the fuzzy logic controller is applied to gain better control when clearing faults.