Abstract : This paper discusses the load distribution scheme of the two motors on the gate hoist when using frequency converter drive, and introduces the handling methods for common faults of frequency converters during operation. Keywords : frequency converter; gate hoist; load distribution; scheme comparison 1 Introduction A hydropower station has a 12-gate flood discharge hoist using frequency converter drive. Since its commissioning, the equipment has been operating unstablely. Common problems include unbalanced and unstable motor load distribution, easy damage to the braking unit and braking resistor, and overcurrent or overfrequency alarms. To solve these problems, we tried several load distribution methods of frequency converter drive, rechecked the capacity of the braking unit and braking resistor, and solved the above problems. The 2×1250L fixed gate hoist of this hydropower station adopts the form of motor-reducer-open gear-drum. In order to ensure synchronous lifting of the two lifting points of the working gate, the high-speed shafts of the two reducers are connected by a rigid shaft. The flat-plate gate weighs 112.88t, with gate dimensions of 14m × 14.6m, a lifting center distance of 9.8m, a rated lifting speed of 1.52m/min, and a lifting height of 25m. It uses two YZ250 squirrel-cage motors with a rated power of 35kW, a rated stator current of 74A, and a rated speed of 681rpm. It uses two A-B1336IMPACT frequency converters with a rated input power of 56kW, a rated output power of 96kVA, a current of 120.9A, and a frequency of 0～400Hz, employing field-oriented control. Each frequency converter is equipped with a braking unit with an input voltage of 680～750VDC, a current of 10ADC, and a maximum heat dissipation power of 3750W for the braking resistor. [b][align=center]For more details, please click: Comparison of Several Load Distribution Schemes When Using Frequency Conversion Drive for Gate Opening and Closing[/align][/b]