At 6:09:06 on December 17, 2014, through the preparation and debugging of all debugging personnel all night long, the Shaanxi Iron and Steel Group's newly built 1780 blast furnace supporting Shaanxi blower was successfully started once and the fan began to operate normally. The device is designed with a frequency conversion soft start of 30000KW, a starting synchronous motor of 27000KW, a rated current of 1700A, a starting time of 220 seconds, a starting current of 280A, a starting multiple of 0.165 times, and the starting current is far lower than the rated current.

　　This ultra-high-power synchronous motor variable-frequency soft-starting system, which is completed by Dayu Electric and Emerson, is different from the traditional method of step-down rectification and inverter through transformer, and then through transformer step-up and isolation to start the extra-large motor. It boldly adopts multiple electric machines in series. Flat "Perfect Non-Harmonic Frequency Inverter" topology, directly output high voltage AC, high efficiency, small size, good starting waveform, small starting current and stable operation. It overcomes the shortcomings of traditional high-low-high frequency conversion soft-starting devices such as large harmonic current, low efficiency, large area, and easy damage to the step-up and step-down transformer. The entire commissioning process went smoothly and the start-up was perfect, which was unanimously appreciated by the owners, general contractors and major contractors present.

　　Dayu Electric will take advantage of the successful start of this 30000KW super-power synchronous motor, and sincerely hope to further strengthen cooperation with new and old users and partners, and make greater contributions to the development of China's soft start and frequency conversion industry.