TY - JOUR
T1 - Adjustable inertial response from the converter with adaptive droop control in DC grids
AU - Wang, Yi
AU - Wang, Chen
AU - Xu, Lie
AU - Meng, Jianhui
AU - Hei, Yang
N1 - (c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.
PY - 2018/3/28
Y1 - 2018/3/28
N2 - In a DC grid, the inherent inertial support from the DC capacitors is too small to resist step changes or random fluctuations from the intermittent power resources, which results in lower DC voltage quality. In this paper, an adaptive droop control (ADC) strategy is proposed to achieve an increased inertia from the droop controlled converter. The adaptable droop coefficient according to the DC voltage variation enables fast swing of the droop curve, so that the converter can provide inertial power for the DC grid like synchronous generators in AC grids. The design of the ADC including the calculation and limitation of the adaptable droop coefficient is analyzed in detail. The small-signal analysis of the DC grid with ADC is provided to identify its stability issue. Experimental tests on a controller hardware-in-the-loop (HIL) platform of a low-voltage (LV) DC grid are carried out to validate the proposed method. In this LV DC grid, the proposed ADC is implemented on the energy storage system (ESS) which provides inertial support to improve the DC voltage quality under different power fluctuations, and smooths the power transmitted to AC grid.
AB - In a DC grid, the inherent inertial support from the DC capacitors is too small to resist step changes or random fluctuations from the intermittent power resources, which results in lower DC voltage quality. In this paper, an adaptive droop control (ADC) strategy is proposed to achieve an increased inertia from the droop controlled converter. The adaptable droop coefficient according to the DC voltage variation enables fast swing of the droop curve, so that the converter can provide inertial power for the DC grid like synchronous generators in AC grids. The design of the ADC including the calculation and limitation of the adaptable droop coefficient is analyzed in detail. The small-signal analysis of the DC grid with ADC is provided to identify its stability issue. Experimental tests on a controller hardware-in-the-loop (HIL) platform of a low-voltage (LV) DC grid are carried out to validate the proposed method. In this LV DC grid, the proposed ADC is implemented on the energy storage system (ESS) which provides inertial support to improve the DC voltage quality under different power fluctuations, and smooths the power transmitted to AC grid.
KW - DC grid
KW - virtual inertia
KW - voltage droop control
KW - variable droop coefficient
KW - adaptive control
UR - http://ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=5165411
U2 - 10.1109/TSG.2018.2820160
DO - 10.1109/TSG.2018.2820160
M3 - Article
SN - 1949-3053
JO - IEEE Transactions on Smart Grid
JF - IEEE Transactions on Smart Grid
ER -