火电机组辅机变频调速系统低电压穿越测试

为了准确分析火电机组变频调速系统的低电压穿越能力，避免火电机组一类辅机（如给煤机、给粉机、空气预热器等）变频调速系统发生短时（小于5 s）电压暂降或中断供电造成设备损坏、机组停机或机组输出功率大量下降，提出了2种利用电压暂降发生器对火电机组辅机变频调速系统进行低电压穿越测试的原理和方法，通过对比分析研究，为变频调速系统改造前的低电压穿越能力实测和改造后的验收试验提供了理论参考，实践结果证明了该方案的可行性和正确性。

Testing Study on the Low Voltage Ride-Through Capability of Thermal Power Unit Auxiliary Machinery Variable Frequency Speed-Regulating System

In order to accurately analyze the low voltage ride-through capability of the thermal power unit variable frequency speed- regulating system for avoiding the equipment damage, unit stop or the sharp drop of unit output power caused by voltage sag in a short time (less than 5 s) or power supply interruption of the variable frequency speed regulation system of important auxiliary machinery of thermal power unit(such as the coal feeder, pulverized coal feeder, air preheater etc.), two methods are proposed for testing the low voltage ride-through capability of the thermal power unit variable frequency speed-regulating system by using the voltage sag generator. A comparative study of the two methods can provide a theoretical reference for testing the low voltage ride-through capability of the variable frequency speed regulation system. The practical application has proved the feasibility and validity of the proposed methods.