压缩机电机起动理论PPT学习教案

1、会计学1 压缩机电机起动理论压缩机电机起动理论 Low Slip v Full Slip 低滑移与满滑移 0 50 100 150 200 250 300 1009080706050403020100 SLIP (%) FULL LOAD TORQUE (%) 0 100 200 300 400 500 600 700 CURRENT (%) When applying AC speed drives the motors low slip performance characteristics are important. 当使用AC速度驱动电机低滑移时，性能特征是十分重要的。 In con

2、trast, when applying soft starters the motors performance at all levels of slip is important. 相反，当使用软起动器时，在满滑移水平下的电机性能是十分重要的。 Soft Start 第1页/共31页 A motors start performance characteristics set the limits of what can be achieved with either a full voltage or reduced voltage starter. 电机起动性能规定使用全电压起动器或

3、降压起动器能达到的极限值。 It is especially important to consider motor start characteristics when seeking to: - Minimise start current -Maximise start torque 当尝试以下方式时考虑电机起动特性尤其重要： - 将起动电流降至最小 - 将起动扭矩增至最大 Motor Performance 电机性能 第2页/共31页 Rotor design affects starting performance. 转子的设计影响起动性能。 Stator design affect

4、s full speed performance. 定子的设计影响全速性能。 The shape, position and material of the rotor bars affect the current drawn and torque produced during motor starting. 转子杆的形状、位置和材料影响引入电流和电机起动时产生的扭矩。 Motor Performance 电机性能 第3页/共31页 A motors start performance can be identified by examining the motor data sheet.

5、 电机起动性能可通过检查电机数据表得到确认。 The table details selected performance data for a range of 110kW motors. 数据表详述了110kW电机系列选用的性能数据。 Typical Motor Data 典型电机数据 MotorSpeedFLCLRCLRT % FLTorque (rpm)(amps)(%FLC)(%FLT) Efncy3xFLC A1470191600263 9365.8 B1475184600190 93.547.5 C1475191570150 9241.6 D1480187660190 94.53

6、9.2 E1470185550120 9236 F1470191670150 9330.1 G1480190780200 9429.6 H1475182850220 93.527.4 I1480190670120 9424 Sample Of Typical 110kW Motors 第4页/共31页 Maximum motor start current under full voltage start conditions is defined by the motors Locked Rotor Current (LRC). 全电压起动条件下最大电机起动电流是由电机锁定转子电流（LRC）

7、确定的。 LRC levels vary considerably between motors. LRC等级在电机间有显著变化。 In the example, Motor H will draw 55% more current at start than Motor E. 在实例中，电机H引入的起动电流比电机E多55%。 Start Current 起动电流 MotorSpeedFLCLRCLRT % FLTorque (rpm)(amps)(%FLC)(%FLT) Efncy3xFLC A1470191600263 9365.8 B1475184600190 93.547.5 C147

8、5191570150 9241.6 D1480187660190 94.539.2 E1470185550120 9236 F1470191670150 9330.1 G1480190780200 9429.6 H1475182850220 93.527.4 I1480190670120 9424 LRC ranges from 550% to 850% Sample Of Typical 110kW Motors 第5页/共31页 Motor start torque performance is indicated by the motors Locked Rotor Torque (LR

9、T) figure. 电机起动扭矩性能是由电机的锁定转子扭矩（LRT）图表示的。 LRT levels vary considerably between motors. LRT等级在各个电机间有显著变化。 In the example, Motor A produces twice as much torque during start as Motor I. 在实例中，电机A起动时产生的扭矩是电机I的两倍。 Start Torque 起动扭矩 MotorSpeedFLCLRCLRT % FLTorque (rpm)(amps)(%FLC)(%FLT) Efncy3xFLC A1470191

10、600263 9365.8 B1475184600190 93.547.5 C1475191570150 9241.6 D1480187660190 94.539.2 E1470185550120 9236 F1470191670150 9330.1 G1480190780200 9429.6 H1475182850220 93.527.4 I1480190670120 9424 LRT ranges from 120% to 263% Sample Of Typical 110kW Motors 第6页/共31页 LRC 2 disconnect from the reduced volta

11、ge (open circuit); 3 connect to the full voltage. Open transition starting causes severe current & torque transients that can be more detrimental to the supply and the mechanical equipment than full voltage starting. When the motor is spinning and then disconnected from the supply, it acts as a gene

12、rator. Output voltage can be the same amplitude as the supply. At the time of reclose there can still be significant voltage present at the motor terminals. Voltage generated by the motor at the instant of reclose may be equal to the supply voltage but exactly out of phase. This equates to reclosing

13、 with twice the supply voltage on the motor. The result is a current of twice locked rotor current and a torque transient of four times locked rotor torque. 第25页/共31页 开路瞬变转换 当起动器以转换顺序通过开路段时发生。1连接降压； 2与降压（开路）断开；3连接满电压。 开路瞬变起动造成严重的电流和扭矩瞬变，这对电源和 机械设备可能比满电压起动更加有害。 当电机旋转、然后与电源断开时，起到发电机的作用。 输出电压可与电源振幅相同。再

14、合闸时，仍可有明显的 电压出现在电机终端。 再合闸瞬间电机产生的电压可与电源电压相等但正好失 相。这等于再合闸电机上有两倍的电源电压。这一结果 是两倍锁定转子电流的电流和四倍锁定转子扭矩的扭矩 瞬变。 第26页/共31页 Soft Starter 软起动器 MotorOverloadAC SwitchesContactor M 3 Soft Starters control the voltage applied to the motor by the use of solid state AC switches (SCRs) in series with the supply to the

15、motor. 软起动器通过与电机电源串接的固态AC开关（ACR）控制电机电压。 第27页/共31页 -Minimum possible start current -No current steps -No torque steps -Good start torque characteristics -起动电流可达最低 -没有电流步进 -没有扭矩步进 -良好的起动扭矩特性 Soft Starter 软起动器 0 50 100 150 200 250 300 1009080706050403020100 SLIP (%) FULL LOAD TORQUE (%) 0 100 200 300 4

16、00 500 600 700 CURRENT (%) 第28页/共31页 Motor characteristics set the limits of what can be achieved with a soft starter. 电机特性决定软起动器所能达到的极限。 Pay special attention to motor characteristics when: 在以下情况下要特别注意电机特性: -it is important to minimise start current - 将起动电流降至最低是十分重要的 - it is important to maximise start torque - 将起动扭矩增至最大是十分重要的 - dealing with large motors (200kW +) - 涉及大型电机（200kW +） Summary 总结 第29页/共31页 Soft start is technically the bes