New High Power Converter

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.