Control strategies to improve stability of LCC‐HVDC systems with multiple MMC taps

Integration of renewable energy sources with LCC HVDC system using a new circuit topology with DC fault ride‐through capability

“…The mathematical expressions for instantaneous values of discharging current and submodule voltage during the discharging process can be derived from (5).…”

“…Integrating renewable energy sources which generate power at low voltage levels with a high-voltage LCC-based HVDC transmission line has a lot of technical challenges [3][4][5]. As the AC network with renewable energy sources form a weak grid, usually voltage source converters (VSCs) are used at the renewable energy source side.…”

“…The challenge is to develop an intermediate power converter for integrating the low-voltage VSC with high-voltage LCC-based HVDC system on which the present work is focussed. Many research works have been conducted in this direction [3][4][5][6][7][8][9], and the power converters proposed in these works can be broadly classified into two types: series configurations and parallel configurations [5].…”

“…The primary challenge of series configuration is the requirement of converters with a high current rating as the entire current of the main HVDC system passes through the tapping scheme [7]. For this reason, the parallel power evacuating scheme has found more acceptance in recent years [5,[9][10][11].…”

“…The parallel configuration can be classified into single-stage and two-stage configurations [5,[9][10][11]. In the single-stage scheme, the DC side of VSC is connected directly to the HVDC line.…”