Parallel breaking characteristics of diode-bridge power electronic switch for DC circuit breaker

With the improvement of the breaking-current level of the DC circuit breaker, the current level of the existing power electronic devices cannot meet the demand of breaking the DC current. However, it can realize high- power DC breaking through the power electronic devices in parallel. In order to reveal the influencing factors and laws of parallel breaking characteristics of power electronic devices suitable for DC breaking, and to break through the parallel technology of power electronic devices suitable for DC breaking, the influence of stray inductance of power electronic switch branches, driving performance of power electronic devices, technical parameters of buffer branches and characteristics of switching current on the characteristics of parallel breaking are studied in this paper, which are based on the Injection Enhanced Gate Transistor (IEGT) and the diode bridge type topological structure of power electronic switches. And then a parallel method of power electronic devices suitable for DC breaking is proposed. Lastly, a power electronic switch module suitable for DC breaking is developed, and a parallel power electronic switch module test is carried out. The experimental results show that the two parallel power electronic switching modules can break 50kA current within 10 mu s, and the maximum non-current sharing of the four IEGTS is 2.1kA. The current sharing characteristics are good, which verifies the effectiveness of the parallel method of power electronic devices suitable for DC breaking. The research results of this paper lay a technical foundation for the engineering application of power electronic switch suitable for DC breaking