Analysis and Suppression for Temporary Overvoltage Considering Dynamic Interactions Between LCC-HVDC and Renewable Energy Plants

Temporary overvoltage (TOV) severely restricts the development and utilization of renewable power resources (RPRs), especially when RPRs are delivered through the line commutated converter-based high voltage direct current (LCC-HVDC) system. To reveal the TOV mechanism for the sending system during commutation failures (CFs), the transient process of the system is partitioned into different stages, where the evolution of the system trajectories is analyzed. On this basis, the variation of AC voltage and DC current considering complex dynamic interactions between LCC-HVDC and renewable energy Plants (REPs) during repetitive CFs (RCFs) is clearly quantified. After revealing the impact of control parameters of both REPs and the LCC-HVDC on the TOV during RCFs, a collaborative optimization method for control parameters is proposed for TOV suppression. Moreover, when the blocking after the RCF tends to be inevitable, the optimal blocking moment is determined to inhibit the TOV caused by HVDC blocking. The accuracy and effectiveness of the proposed methods are verified with EMT simulations of a typical benchmark system.