永磁耦合调速电机实现火电厂给煤机低电压穿越

LVRT for Coal Feeder of Thermal Power Plant Realized by Permanent Magnet Coupling Speed Regulating Motor

电网电压短暂跌落往往会触发火电厂给煤机的变频器保护动作,从而影响正常的电力生产。提出了一种采用永磁耦合调速电机构建给煤机的电动系统,依靠电机性能解决低电压穿越问题的方法。分析了永磁耦合调速电机实现低电压穿越性能的工作原理,设计了双闭环控制系统。建立5.5 kW给煤机电动系统试验平台进行试验,试验结果表明:永磁耦合调速电机及其控制系统的快速性和准确性优良,在电网发生短暂电压跌落时,能够维持给煤机正常工作,具有低电压穿越能力。

Power grid voltage sag often causes protection action of the coal feeder frequency converter in the thermal power plant,which affects the normal power production.A novel means of using the permanent magnet coupling speed regulating motor in coal feeder is proposed to realize low voltage ride-through(LVRT)by the motor's properties.The LVRT operating principle of the permanent magnet coupling speed regulating motor is analyzed.The double-closed-loop control system is designed.A 5.5 kW electrical drive system experimental platform of the coal feeder is built.The experimental results show that the proposed motor and its control system have good rapidity and accuracy,and when voltage sag occurs in the power grid,the coal feeder can work normally and have LVRT ability.