一种混合子模块柔直换流阀启动方法

Startup Strategy of Hybrid Sub-module Flexible HVDC Converter

目前,国内已建和在建的模块化多电平柔性直流输电(HVDC)工程均采用半桥型子模块(HBSM)换流阀技术路线。HBSM换流阀不具备直流故障穿越能力,极大地限制了HVDC技术的应用。国内外学者又相继提出了诸多新型换流器,其中HBSM和全桥子模块(FBSM)混合型模块化多电平换流器(MMC)在具备直流故障穿越能力的同时降低了开关器件的数量,成为目前HVDC发展的主要方向。FBSM具备与HBSM不同的充放电特性,因此混合子模块之间的电压均衡控制是传统的排序均压算法无法胜任的。在此提出一种半桥和全桥混合子模块均压控制启动策略,解决了半桥和全桥混合子模块换流阀不同模块之间均压和直流电压突变的问题。

At present,the domestic has been built and under construction in modular multilevel high voltage direct current transmission（HVDC） project are used half-bridge sub-module（HBSM） converter valve technology line.HBSM converter valve does not have the DC fault crossing ability, which greatly limits the application of HVDC technology.Domestic and foreign scholars have put forward a number of new converter, including HBSM and full-bridge submodule（FBSM） hybrid modular multilevel converter（MMC） with DC fault crossing capability while reducing the number of switching devices to become the current main direction of HVDC.The FBSM has different charge-discharge characteristics from the HBSM.Therefore, the voltage equalization control between the hybrid sub-modules is the traditional sorting pressure equalization algorithm.A half-bridge and full-bridge hybrid sub-module equalization control startup strategy is proposed to solve the problem of pressure and DC voltage variation between different modules of half-bridge and full-bridge hybrid sub-module converter valve.