Abstract
This paper presents an improved droop-based control strategy for the active and reactive power-sharing on the large-scale Multi-Terminal High Voltage Direct Current (MT-HVDC) systems. As droop parameters enforce the stability of the DC grid, and allow the MT-HVDC systems to participate in the AC voltage and frequency regulation of the different AC systems interconnected by the DC grids, a communication-free control method to optimally select the droop parameters, consisting of AC voltage-droop, DC voltage-droop, and frequency-droop parameters, is investigated to balance the power in MT-HVDC systems and minimize AC voltage, DC voltage, and frequency deviations. A five-terminal Voltage-Sourced Converter (VSC)-HVDC system is modeled and analyzed in EMTDC/PSCAD and MATLAB software. Different scenarios are investigated to check the performance of the proposed droop-based control strategy. The simulation results show that the proposed droop-based control strategy is capable of sharing the active and reactive power, as well as regulating the AC voltage, DC voltage, and frequency of AC/DC grids in case of sudden changes, without the need for communication infrastructure. The simulation results confirm the robustness and effectiveness of the proposed droop-based control strategy.
Highlights
For long-distance transmission, Multi-Terminal High Voltage Direct Current (MT-HVDC) grids are utilized to transfer the generated power from offshore AC sources, e.g., wind farms, to onshore AC voltage within a certain range at all the system buses
The droop controller’s limits prevent the active power deviation generated by the DC voltage-droop controller, the active power deviation generated by the frequency-droop controller and the reactive power deviation generated by the AC voltage controller of the ith converter of the MT-HVDC system from becoming higher than ±∆PVDCimax, ±∆P fimax, and ±∆QVACimax, respectively
System consisting of five Voltage-Sourced Converter (VSC)-HVDC stations connected to different types of AC systems is modeled in PSCAD/EMTDC and MATLAB software
Summary
For long-distance transmission, Multi-Terminal High Voltage Direct Current (MT-HVDC) grids are utilized to transfer the generated power from offshore AC sources, e.g., wind farms, to onshore AC grids. In AC/DC grids, two parameters should be considered: (1) The DC voltage at different buses for the DC grids to share the power. (2) The frequency for the AC grids to minimize the deviations in power, and among the other interconnected AC grids. There are several methods to perform the operation of power-sharing control and frequency and voltage regulation [17,18,20,21,22,23]. These control strategies can be classified into two main categories: (1) master-slave technique and (2) distributed DC voltage control strategy.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
