PROJECT TITLE :

Adaptive Droop Control of VSC-MTDC System for Frequency Support and Power Sharing - 2017

ABSTRACT:

This paper proposes an adaptive droop control (ADC) strategy for the voltage supply converter (VSC) primarily based multiterminal high voltage direct current (VSC-MTDC) system, that enables the VSC-station to produce frequency regulation for onshore ac grids. A V-I-f characteristic comes to ascertain the link between the frequency deviation and dc voltage. A VSC-station operating with the V-I-f characteristic is able to adjust its dc voltage reference autonomously according to the grid frequency deviation. Thus, the power flow of the VSC-MTDC system will be redistributed and more power is going to be injected into the adjacent grid of that the frequency deviation exceeds the edge value. The ADC strategy inherits the advantage of the traditional droop management (TDC) that there's no want for Communication system. An ac/dc hybrid system that features VSC-MTDC system, onshore grids, and offshore wind farms is constructed in DIgSILENT/Powerfactory. Modal analysis and nonlinear simulations are performed to obtain the optimal management parameters and demonstrate the performance of the ADC strategy.