DTC直接转矩控制技术介绍解读.ppt

DTC Basics and Benefits Back to Basics Basic drive configuration Direct Torque Control basics Flux vector versus DTC 磁通矢量与DTC Flux vector control can calculate torque control only at 1-3 ms intervals. A modulator is needed to calculate switching times Control response is around 10 ms Select feature or application requirement Select feature or application requirement Less stress on mechanics Backlash appears in gearboxes and couplings. In backlash range motor may accelerate leading to backlash impact. Fast DTC control limits impact. Mechanical resonances often appear due to elasticity of shafts or web and inertias of motor, gearbox and driven machine. Fast DTC attenuates the resonances. Applications with high demand of load stiffness The use of encoder in ACS600 Encoder is NOT needed when high starting torque is needed the need for absolute accuracy of torque is more than 4% as typically the case is the need for absolute accuracy of speed is more than 10 % of motor slip (typically 0.2 Hz electrical speed) The use of encoder in ACS600 Encoder needed when active load like in hoist or lift applications and operating below slip frequency is needed the linearity of torque over the whole speed range is critical like in winder applications What to do if not sure whether to use or not Some Reminders What do competitors say on their drives without encoder Starting torque without encoder Torque Linearity Torque linearity stands for drive capability to produce the same torque actual value in the motor shaft with given constant torque reference value exactly in every speed point in generator and motor area DTC linearity example without encoder DTC - linearity example with encoder Here the encoder improves ABB Industry Oy Drives Group - Product AC Page * Presentation Name or No. Page * Unit Name L Torque=F*L*sin(?) L F ? Torque is the arm length multiplied by force in right angle to shaft Direct Torque Control makes what we all know to be the best way to get muscl