大型抽水蓄能机组静止变频起动控制技术研究

Research on Static Frequency Start-up Control Technology for Large Pumped Storage Unit

抽水蓄能机组起动时需较大的电磁转矩,同时要保证起动电流小,需采用静止变频器来拖动机组静止起动与变频运行。为此,介绍一种整流桥和逆变桥的每相上下桥各由5个晶闸管串联而成的高压静止变频器。其中,整流桥采用转速外环和电流内环双闭环控制,触发脉冲为工频控制;逆变桥根据转速范围采用不同的转子位置估算方法,采用脉冲换相和负载换相组合的换相控制方法,触发脉冲为变频控制;高压变频器输出可旁路运行切换至带变压器运行,也可一直带变压器运行。通过试验验证了高压变频器具有较好的起动和变频调速性能、整流桥和逆变桥控制策略有效、两种输出运行方式可靠。

When starting a pumped storage unit, it needs large electromagnetic torque and small starting current. Therefore, it is necessary to use static frequency converter to drive the machine for static starting and variable frequency operation. So, a high voltage static frequency converter composed of five thyristors in series for each phase of rectifier and inverter was introduced. The rectifier adopted double closed-loop control of speed outer loop and current inner loop, and the trigger pulse was power frequency control. The inverter adopted different rotor position estimation methods according to the speed range, and the commutation control method of pulse commutation and load commutation was adopted. The trigger pulse was the frequency conversion control. The output of high-voltage frequency converter could be switched from bypass operation to operation with transformer or always with transformer. Through experiments, it was verified that the high-voltage inverter has good starting and variable frequency speed regulation performance, the effectiveness of rectifier and inverter control strategy, and the reliability of two output operation modes.