【摘要】 利用特高压直流输电技术实现新能源场站远距离输送是今后的重点发展方向，但存在着输送系统薄弱、易受到干扰而出现暂态过电压的问题。光伏并网系统、光伏场站存在大量电力电子无功源，在无功调节时控制环节的滞后性也会助增暂态过电压，为提高特高压直流输电光伏并网系统的稳定性和可靠性，有必要对其暂态过电压原理进行分析。为此，建立了光伏场站、SVG和光伏并网系统的等值仿真模型，通过PSCAD仿真平台模拟分析了换相失败、直流闭锁等典型直流故障下光伏并网系统的暂态过电压工况，从而揭示了特高压直流输电光伏并网系统典型直流故障场景下的暂态过电压机理。更多还原

【Abstract】 The utilization of Ultra-High-Voltage Direct Current(UHVDC) transmission technology for the long-distance transmission of renewable energy, particularly from photovoltaic(PV) stations, is a critical future development.However, this approach faces challenges such as a weak transmission system prone to disturbances, leading to transient overvoltage problems.In PV grid-connected systems, the presence of numerous power-electronic-based reactive power sources in PV stations, combined with control loop delays during reactive power regulation, can further exacerbate transient overvoltage.To enhance the stability and reliability of UHVDC PV grid-connected system, it is essential to analyze the mechanisms underlying transient overvoltage.To address this, equivalent simulation models for PV stations, Static Var Generators(SVG),and PV grid-connected systems are first established.Then, the PSCAD simulation platform is employed to simulate and analyze transient overvoltage conditions in PV grid-connected systems under typical DC faults, such as commutation failure and DC blockages.The simulations reveal the transient overvoltage mechanisms in UHVDC PV grid-connected systems under these typical DC fault scenarios.更多还原