Thermal reliability has a very important influence on the performance and service life of Neutral Point Clamped (NPC) three-level SVG. Continuous pulse width modulation (CPWM) has the disadvantages of high switching loss and low reliability when applied to three levels. To solve this problem, a dynamic discontinuous pulse width modulation (DDPWM) strategy is proposed in this paper, which can reduce the switching loss of power components of the three-level converter and improve the thermal reliability of the converter. At the same time, the thermal reliability of the three-level converter is analyzed from the Angle of the influence of junction temperature on the device bond line. Finally, Simulation and experiments verify that the algorithm proposed in this paper is simple and reliable, can effectively reduce the loss, and has a certain engineering.

three-level SVG; thermal reliability; switching loss;