CAJ | 학술논문

给出了10 kV配电网基于模块化多电平变换器技术的统一电能质量控制器(modular multilevel converter based unified power quality conditioner,MMC-UPQC)装置提高实用性的五种方法。第一种方法采用变比可变的变压器代替传统MMC-UPQC的串联变压器,提高了 MMC-UPQC 电压暂降补偿深度；第二种方法采用双串联变换器串联代替传统MMC-UPQC的单串联变换器,减小了公共直流侧电压,降低了阀组柜绝缘要求；第三种方法在电压暂降期间控制并联变换器吸收适量的有功功率,减少了 MMC-UPQC 子模块直流电容的释放能量,减小了直流电容的容量；第四种方法MMC-UPQC子模块采用混频控制,根据子模块需治理的电能质量问题设定控制脉冲的频率,减少了子模块内开关器件损耗,降低了散热措施要求；第五种方法在控制策略中引入环流抑制控制,减小了MMC-UPQC变换器内部的环流电流及桥臂电抗器感抗。与传统 MMC-UPQC 装置相比,采用所提五种方法的MMC-UPQC装置能提高电压暂降补偿能力,减小占地面积和成本。
급출료10 kV배전망기우모괴화다전평변환기기술적통일전능질량공제기(modular multilevel converter based unified power quality conditioner,MMC-UPQC)장치제고실용성적오충방법。제일충방법채용변비가변적변압기대체전통MMC-UPQC적천련변압기,제고료 MMC-UPQC 전압잠강보상심도；제이충방법채용쌍천련변환기천련대체전통MMC-UPQC적단천련변환기,감소료공공직류측전압,강저료벌조거절연요구；제삼충방법재전압잠강기간공제병련변환기흡수괄량적유공공솔,감소료 MMC-UPQC 자모괴직류전용적석방능량,감소료직류전용적용량；제사충방법MMC-UPQC자모괴채용혼빈공제,근거자모괴수치리적전능질량문제설정공제맥충적빈솔,감소료자모괴내개관기건손모,강저료산열조시요구；제오충방법재공제책략중인입배류억제공제,감소료MMC-UPQC변환기내부적배류전류급교비전항기감항。여전통 MMC-UPQC 장치상비,채용소제오충방법적MMC-UPQC장치능제고전압잠강보상능력,감소점지면적화성본。
Five methods are proposed in this paper to improve practicability of the modular multilevel converter based unified power quality conditioner (MMC-UPQC)equipment in 1 0 kV distribution network.In the first method,variable turn ratio transformers are used to replace series transformer of the traditional MMC-UPQC,which increases the voltage sag compen-sation depth.In the second method,two series converters in series are used to replace single series converter in the traditional MMC-UPQC,which reduces the common DC link voltage level and decreases the insulation requirement of the valve set cab-inet.In the third method,shunt converter absorbs appropriate quantity active power during the voltage sag,which reduces releasing energy of the DC capacitors in sub-modules and decreases capability of the DC capacitors.In the fourth method, hybrid frequency control sub-modules are used in MMC-UPQC and the frequencies of sub-modules are set by power quality problems they handled,which reduces the switching power loss in sub-modules and decreases cooling requirement.In the fifth method,circulating current suppressing control is introduced in control strategy,which reduces the circulating current in MMC-UPQC’s converters and decreases inductance of the arm inductors.Compared with the traditional MMC-UPQC, MMC-UPQC with the proposed five methods can increase the voltage sag compensation capability and decrease the area and cost.