TY  - EJOU
AU  - Zhang, Xiaohu 
AU  - Xu, Ling 
AU  - Lou, Keheng 
AU  - Wang, Guoteng 
AU  - Huang, Ying 

TI  - Research on Voltage Stability Analysis and DC Technological Route Selection Strategy for Multi-Infeed Hybrid DC Receiving-End Grids
T2  - Energy Engineering

PY  - 
VL  - 
IS  - 
SN  - 1546-0118

AB  - Against the backdrop of the global energy transition, receiving-end grids with multi-infeed hybrid DC systems face severe risks of voltage support capability degradation and transient instability. To address this issue, this paper conducts a systematic study from three perspectives: multi-dimensional indicator evaluation, underlying mechanism analysis, and capacity planning optimization. First, going beyond traditional single impedance-magnitude indicators, a comprehensive multi-dimensional voltage stability evaluation framework is constructed, which encompasses steady-state voltage stiffness, transient Critical Clearing Time (CCT), Transient Voltage Recovery Time (TVRT), and the Multi-Infeed Interaction Factor (MIIF). Second, the mathematical models of the steady-state and transient electrical external characteristics for Line-Commutated Converters (LCC) and Modular Multilevel Converters (MMC) are established. Through the analysis of the Jacobian incremental matrix and the rigorous solution of transient differential equations, the mechanisms by which the MMC injects controlled transient admittance to enhance nodal voltage stiffness, restrain the accumulation of transient destructive energy, and achieve dynamic decoupling among multiple DC systems are clarified from a mathematical perspective. Finally, an LCC-MMC hybrid DC technological route and capacity allocation optimization strategy that balances overall economic performance with multi-dimensional security constraints is proposed. Aiming at maximizing the net economic benefit of the system, this strategy coordinates the differential construction costs of converters, avoided costs for supplementary reactive-power equipment, and the voltage-support benefits for existing DC systems, while embedding multi-dimensional voltage stability as strong constraints into the optimization framework. Simulations based on the modified IEEE 39-bus system indicate that the proposed optimization strategy quantifies the effects of the converter capacity allocation ratio on overall system stability, thereby achieving a constrained feasible optimum of system investment economics under a discrete grid search over the LCC capacity, while satisfying the transient security boundaries.
KW  - Multi-infeed hybrid DC; voltage stability; LCC-MMC hybrid HVDC; capacity allocation optimization

DO  - 10.32604/ee.2026.086160