具备无闭锁穿越直流故障能力的直流自耦变压器

摘要

A novel topology of DC/DC converter is proposed,termed as un-interrupted DC Autotransformer(DC AUTO), which has capability to ride through the DC fault on either side of the converter without de-blocking any devices.Firstly,the characteristics of the DC AUTO and its defects are analyzed.Aiming at the problem that current DC AUTO cannot ride through the DC fault,the requirements for the ability of riding through the DC fault are analyzed as well.On the basic of that, combined with the characteristics of the hybrid modular multilevel converter(hybrid-MMC),the hybrid-MMC number of DC AUTO with the ability of riding through the DC fault without de-blocking any devices is designed.Then,an effective control strategy is proposed to enable the converter keeping in the steady operation during both normal and fault conditions.Finally,a test system is built on PSCAD/EMTDC platform to verify the technical feasibility of the proposed converter and the effectiveness of the proposed control strategy.%首先,分析了目前直流自耦变压器技术的特点及其缺陷所在,针对目前直流自耦变压器无法穿越直流故障的问题,分析了直流自耦变压器穿越直流故障的需求,在其基础上结合混合型模块化多电平换流器的特点,设计了具备无闭锁可穿越直流故障的直流自耦变压器子模块数目配比.其次,设计了该变压器的控制策略,保证其在正常工况和故障工况下的稳定运行.最后,在 PSCAD/EMTDC下搭建了测试系统,验证了所提无闭锁穿越直流故障直流自耦变压器技术的可行性及控制策略的有效性.