Abstract: A test method was proposed that can evaluate the ultimate power output capability of large capacity

IGCT three-level converter. Based on synchronous symmetrical PWM modulation and temperature estimation

model，the power experiment of IGCT three-level converter was carried out，which can test the equipment capacity

under different load power factors and reversible operation，and achieve accurate evaluation of power device

temperature rise. This method uses PWM pulse width real-time adjustment to change the voltage difference

between the two ends of the load inductor. Compared with the general synchronous modulation method，which

directly changes the angle or voltage of the table lookup，this method further reduces the current ripple and makes

the test current closer to the actual situation.

      Key words: three-level converter；integrated gate commutated thyristors（IGCT）；power test；synchronization

modulation