光伏(PV)全直流汇集与送出系统中，高压直流(HVDC)侧发生短路故障导致功率消纳能力下降，光伏无法及时感知故障而功率不变，导致系统过压停运。为解决此问题，提出了一种基于主动电压抬升的故障穿越策略，当高压直流变压器高压侧子模块电压上升到某一水平时，增加中压侧投入的子模块总数以提升中压直流电压，配合具有故障态P-V下垂特性的最大功率点跟踪(MPPT)装置，实现子模块未过压情况下最大功率点跟踪进入限功率模式，实现高压直流变压器端口功率平衡，达到降低子模块过压、完成故障穿越的效果。对所提策略下HVDC变压器子模块过压进行了分析，并仿真验证了策略的有效性和必要性。

In the photovoltaic (PV) full DC collection and transmission system, a short circuit fault on the high voltage DC (HVDC) side will lead to a decrease in power absorption capacity of the high voltage side DC grid. PVs cannot detect the fault of the high voltage side DC grid in time, therefore its output power remains unchanged, which results in the system overvoltage and causes the system to shut down. To address this problem, a fault ride through strategy based on the active voltage rise is proposed. While the voltage of the high voltage side submodule of the high voltage DC transformer is risen to a certain level, the number of the medium voltage side submodules which output the high voltage level is increased to rise the voltage of the medium DC bus. And with the maximum power point tracking (MPPT) converters which have the function of fault state P-V droop, the MPPTs enter the power limiting mode in advance to achieve the power balance of the high voltage DC transformer, thus reduces the overvoltage of the submodule capacitor, and achieves the fault ride through function. The overvoltage of the HVDC transformer submodule under the proposed strategy is analyzed, and the effectiveness and necessity of the strategy are verified by simulation.

国网浙江省电力有限公司项目（5211DS230005）