一种大容量变流器  

New High Power Converter

作　　者：王连符[1] 肖峻[2] 

机构地区：[1]唐山职业技术学院机电工程系,唐山064002 [2]天津大学电气工程及其自动化学院,天津300072

出　　处：《高电压技术》2007年第5期180-183,188,共5页High Voltage Engineering

摘　　要：为了提高高压大容量变流器的输出精度和可靠性,提出了一种采用不同类型器件组合的变流器新方案,即主电路每个桥臂上侧采用m只低速开关的大功率电力电子器件IGCT(ETO)串联,下侧采用n只高速开关的大功率电力电子器件IEGT(IGBT)并联。该结构除了增大变流器单元容量外,上侧串联的IGCT(ETO)可防止全部由IEGTI、GBT并联产生的直流源短路,且即使其中一个器件损坏,变流器仍能正常运行,便于事故报警后及时更换所坏器件,防止事故扩散,故可靠性高;同时,脉宽调制(PWM)控制采用分时处理技术,定量分析了采用分时处理技术对器件发热量以及载波信号极限频率的影响。最后,给出了由不同类型器件组成的二电平变流器的实用电路,并对实现该方案的不同类型器件的参数匹配进行了探讨,为今后设计、使用此类变流器提供参考。Converters are key components of many advanced electric installations in modern power system, such as static var compensator （STATCOM）, active power filter （APF） and etc. Chosen of power electronic devices, topology, monitoring and implementation have important influences on the performances and costs of the converter. In order to enhance precision and reliability of high power converter, a novel circuit structure of hybrid-type-component is established. Up side of each arm-pair in main circuit consists of low switching frequency power electronic device, like Integrated Gate Commutation Thyristor （IGCT）, Emitter Turn-Off thyristor （ETO）, even if series-connected device. Meanwhile, low side consists of high switching frequency device, like Injection Enhanced Gate Bipolar Transistor （IEGT）, Insulated Gate Bipolar Transistor （ IGBT）, or parallel-connected devices. The new structure increases unit capacity, also can prevent straight-through short circuit of converter arm. With the characteristic of specific device, the converter can hold up when one or more device failure. Redundant devices in this circuit structure get more reliability. Time-sharing PWM method is added to parallel-connected devices, it can decrease the heat created by each device, then the converter can work with a high equal carrier frequency. The design trade offs of thermal, power capacity, carrier limitation and PWM performance are analyzed in quantitative manner. A practical circuit diagram of two-level converter is given,and mutual matching of the parameters with hybrid components is discussed in detail. It gives a reference of hybrid components design of converter for this novel topology.

关 键 词：变流器 拓扑结构 容量 精度 可靠性 器件组合 分时处理技术 

分 类 号：TM461[电气工程—电器]