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多电平逆变器适用于高压大功率的应用场合，但其结构复杂，所需的功率开关器件众多，给电路的设计和性能测 试带来很多新问题。为了测试各开关器件的电压电流应力、缓冲电路抑制电压尖峰的效果和层叠式复合母排的性能，该文针对一台高压大功率二极管箝位型三电平变流器，提出一种四管动作的双脉冲测试方法，该方法不同于用常规的斩波电路进行双脉冲测试，而是在实际装置中进行，能够模拟变流器正常工作时的所有换流模态，更真实地反映各功率开关器件的动态特性。若双脉冲的时序和脉宽设计不当，功率开关器件会出现非正常的换流模态和很大的关断过电压，过大的关断过电压可能导致器件失效。该文深入研究了产生过电压的原因并得出故障时封锁脉冲的时序。该文研究成果为二极管箝位型三电平全桥电路的测试提供了有效手段，对于设计可靠的三电平变流器具有理论和现实意义。“,”Multi-level inverters are applicable to the operation states with high voltage and high power. However, these inverters have complex topologies and need many devices, so it is difficult to design a circuit and to test its performance. In order to test the voltage and current stresses during the switching, the effect of restraining voltage peaks of the buffer circuit and the capability of the laminated compound bus bar, this paper proposed a novel four-switch action double-pulse test method for the high-voltage high-power diode clamp three-level converter. Being different with the conventional method for chopping circuits, this method is used in the real equipment. It can be used for simulating the operating mode of each power device and reflecting its dynamic performance. If the sequence and width of the double-pulse are improperly designed, irregular commutation modes and large turn-off overvoltage will appear in some devices, which may lead them to failure. This paper profoundly studied the cause of the overvoltage and found the sequence of locking pulse when a fault occurred. The results provide effective means to test the diode clamp three-level full-bridge circuit. The method is of theoretical and realistic significance to the design of a reliable three-level converter.