Abstract : This paper analyzes the causes of boiler pulverized coal feeder tripping during operation, which led to generator unit tripping. It identifies existing problems and solutions, and provides useful suggestions for the infrastructure construction and operation and maintenance of thermal power equipment. Keywords: Pulverized coal feeder, frequency converter, shielding. A domestic power heating company has two 125MW thermal power heating units, with a generator-transformer-line unit connection. The unit control uses a DCS control system. The boiler is a 435t/h coal-fired boiler, and the boiler pulverized coal feeding system is equipped with 16 variable frequency speed-regulating pulverized coal feeders. The frequency converters are ABB ACS400 series products. 1. Accident Description On April 5, 2004, Unit 1 of the power heating company was operating normally with a generating load of 110MW. Unit 2 was undergoing normal maintenance according to the unit maintenance plan. At 20:03 on April 5, 2004, Boiler No. 1 experienced a MFT (Mechanical Furnace Trip) activation, causing Unit No. 1 to trip during operation. The initial cause of the MFT activation was the complete furnace shutdown of Boiler No. 1. Despite no faults found during equipment and operational checks, Unit No. 1 tripped again, reaching parallel operation with the system at 00:11 on April 6, 2004, and gradually began to take over the load according to dispatch instructions. 2. Accident Investigation and Analysis Process After the accident, the power company organized operating and technical personnel to conduct an accident analysis, including continuous on-site equipment inspections and data collection over the following days, recording and printing historical trends of relevant parameters, and conducting electrical tests. The most direct cause of the unit trip, as obtained from the DCs monitoring screen of Unit No. 1, was the simultaneous tripping of the 14 pulverizers operating at the time, at 20:03:08 on April 5, 2004. This led to the complete furnace shutdown of Boiler No. 1 and the activation of the MFT, resulting in the tripping of the unit during operation. In response to the above reasons, a comprehensive investigation and analysis of the entire process was conducted from an electrical perspective. [b][align=center]For details, please click: Investigation and Analysis of Generator Set Trip Caused by Boiler Feeder Trip[/align][/b]