With the continuous expansion of the UHVDC transmission capacity from Northwest China
the coupling effects among DC clusters and between the AC and DC systems are increasingly intensified
posing challenges to the secure and stable operation of the sending-end grid. Therefore
this paper proposes a multi-objective optimization method for DC terminal siting oriented to the stability of the sending-end grid. Firstly
based on the mechanism of multi-DC coupling interactions
the calculation method for the multi-send short-circuit ratio (MSCR) is derived
and the main influencing factors on the stability of the AC/DC system are analyzed. Secondly
corresponding evaluation indices are established from three dimensions:DC coupling level
AC/DC system strength
and voltage stability. Combined with the security and stability constraints of the sending-end grid
a multi-objective optimization model for DC siting is formulated. Then
an improved entropy weight method is employed to determine the weights of each optimization objective
thereby proposing a method for selecting DC terminal locations that considers sending-end grid stability. Finally
based on actual power grid data
a case study is constructed. For a set of pre-selected DC candidate locations
electromechanical transient simulations are conducted using the power system simulation software PSASP to obtain the optimal siting scheme. Simulation results under multiple fault scenarios demonstrate that this scheme achieves the best performance in suppressing transient overvoltage
verifying the effectiveness and feasibility of the proposed method.
XIAO H,LI Y,SHI D,et al. Evaluation of strength measure for static voltage stability analysis of hybrid multi-infeed DC systems [J ] .IEEE Transactions on Power Delivery,2019,34(3):879-890.