采用永磁电动机驱动的磨煤机控制优化研究

Research on the Control Optimization of Coal Pulverizer Driven by Permanent Magnet Synchronous Motor

燃煤发电厂传统制粉系统采用工频异步电动机驱动,当运行时间较久导致系统参数变化后,容易出现制粉系统出力降低、电耗增大等问题。为了研究磨煤机转速、加载力、煤粉细度和磨煤机出力之间的关系,分析磨煤机电动机采用稀土永磁电动机和中压变频器后的运行方式,设计一系列试验方案测得改造后制粉系统在不同转速、不同工况下的指标,根据试验结果给出磨煤机在轻载、中载、重载下的转速设定推荐值,指导磨煤机驱动系统的优化运行。

In coal-fired power plants,the traditional pulverizing systems are driven by power-frequency asynchronous motors,which,with the change of parameters after long-time operation,may lead to problems including output power decrease and power consumption increase of the systems.To study the relationship among rotation speed,loading force,pulverized coal fineness and output power of pulverizer,this paper analyzes the operation modes of the coal pulverizers who adopts rare earth permanent magnet synchronous motor and middle-voltage frequency converter.A series of experiments were devised to measure the indicators of the retrofitted pulverizers at different rotation speeds and in different working conditions.Based on the experiment results,recommended speed values were given for the pulverizers under light load,medium load,and heavy load to guide the optimal operation of the driving system.