内反馈高频斩波调速在胜利电厂一次风机上的应用

The Application of Internal Feedback High Frequency Chopper Wave Speed Regulating Technology in Primary Fans of Shengli Power Plant

电厂一次风机作为电厂重要的辅机设备,一直靠调节风门开度来适应工况变化,电能利用率低,亟需通过高效率、低投入的电动机调速方式来节能。内反馈高频斩波调速系统由绕线式调速电动机和内反馈高频斩波调速装置两部分组成,融合"内馈调速"和"斩波控制"两项专利技术于一体,具有效率高、谐波小、安全性好等优点,是一种通过功率控制来实现低压控高压的新型、高效率高压电机调速技术。基于此,胜利电厂决定采用内反馈高频斩波调速控制技术,同时将电机由原来的鼠笼式异步电动机更换为绕线式调速特种电动机,于2014年4月份对3号机组一次风机电动机及其控制系统进行了改造;一次风机电动机及调速装置于5月安装完毕后,进行了3个阶段的调试;在调试过程中,出现了电动机在全速转调速的过程中,转换未成功的问题,解决方案是修改PLC逻辑控制。通过该改造方案,理论上,在供风量减少20%的情况下,可以节约能源49%。

As important auxiliary equipment,the primary fan of a power plant has long been relying on the degree of opening of air dampers to adapt to a change in working conditions,resulting in low power utilization rate and an urgent need for saving energy through high-efficiency,low-investment motor-based speed regulation.An internal feedback high frequency chopper wave speeding regulating system consists of a wound rotor motor and an internal feedback high frequency chopper wave speed regulating unit,integrating two patented technologies,namely ＂internal feedback speed regulation＂ and ＂chopper wave control＂.This technology features high efficiency,small harmonic waves and high safety and is a new type of high-efficiency high-voltage motor speed regulating technology by using power control to regulate high voltage with low voltage.Therefore,the Shengli Power Plant decided to introduce the internal feedback high frequency chopper wave speed regulating and control technology and meanwhile substituted a special wound rotor motor for the original squirrel cage asynchronous motor.In April 2014,the plant revamped the motor of the primary fan of its No.3 generating set as well as its control system.After completing installation of the primary fan motor and the speed regulating unit in May,the plant conducted three phases of commissioning on these units and witnessed a failure of conversion of the motor from full speed to regulated speed.The solution was to modify the PLC.Through that revamping scheme,theoretically,energy use could drop by 49% when air supply falls by 20%.