Abstract The non-deterministic nature of power fluctuations in renewable energy sources impose challenges to the design of DC voltage-droop controller in Multi-Terminal High-Voltage DC (MTDC) systems. Fixed droop control does not consider converters’ capacity and system operational constraints. Consequently, an adaptive droop controller is counseled for appropriate power demand distribution. The previous adaptive droop control studies based on the converters’ Available-Headroom (AH) have lacked the demonstration of the droop gain design during consecutive power disturbances. In this paper, the design of the adaptive DC voltage droop control is investigated with several approaches, based on the permitted converters’ global and/or local AH and Loading Factor (LF). Modified adaptive droop control approaches are presented along with a droop gain perturbation technique to achieve the power-sharing based on the converters’ AH and LF. In addition, the impact of Multi-Updated (MU), Single-Updated (SU), and Irregular-Updated (IU) droop gains is investigated. The main objective of the adaptive droop control design is to minimize the power-sharing burden on converters during power variations/consecutive disturbances while maintaining the constraints of the DC grid (i.e., voltage and power rating). The presented approaches are evaluated through case studies with a 4-terminal and 5-terminal radial MTDC networks.

中文翻译：

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多端高压直流输电网络中应急通用直流电压下垂控制设计的通用方法

摘要 可再生能源功率波动的非确定性给多端高压直流 (MTDC) 系统中的直流压降控制器设计带来了挑战。固定下垂控制不考虑转换器的容量和系统操作限制。因此，建议自适应下垂控制器进行适当的电力需求分配。之前基于转换器可用余量 (AH) 的自适应下垂控制研究缺乏连续功率扰动期间下垂增益设计的演示。在本文中，基于允许的转换器的全局和/或局部 AH 和负载因数 (LF)，采用多种方法研究了自适应直流电压下垂控制的设计。提出了改进的自适应下垂控制方法以及下垂增益扰动技术，以实现基于转换器的 AH 和 LF 的功率共享。此外，还研究了多更新 (MU)、单更新 (SU) 和不规则更新 (IU) 下垂增益的影响。自适应下垂控制设计的主要目标是在保持直流电网的约束（即电压和额定功率）的同时，在功率变化/连续干扰期间最大限度地减少转换器的功率共享负担。所提出的方法通过具有 4 端和 5 端径向 MTDC 网络的案例研究进行评估。自适应下垂控制设计的主要目标是在保持直流电网的约束（即电压和额定功率）的同时，在功率变化/连续干扰期间最大限度地减少转换器的功率共享负担。所提出的方法通过具有 4 端和 5 端径向 MTDC 网络的案例研究进行评估。自适应下垂控制设计的主要目标是在保持直流电网的约束（即电压和额定功率）的同时，在功率变化/连续干扰期间最大限度地减少转换器的功率共享负担。所提出的方法通过具有 4 端和 5 端径向 MTDC 网络的案例研究进行评估。