Index
Converter (continued) power-factor, 146 reversing drive, 144–6 single-pulse, 56 six-pulse, 61 supply effects, 146 twelve-pulse, 62 two-pulse, 57 voltage range, 64 Cooling, devices, 75 Cycloconverter drive, 300 D.C. motor: armature reaction, 105 base speed, 67, 114 braking, dynamic, 124 commutator, 86 compensating windings, 106 compound, 119 constant power region, 104 constant torque region, 103 discontinuous current, 139 drives, 133 dynamic behaviour, 108 dynamic braking, 104 equivalent circuit, 94 field weakening, 104 four-quadrant operation, 119, 143 interpoles, 90 ironless rotor, 161 motional e.m.f., 90 no-load speed, 97 printed armature, 161 regenerative braking, 119 reversal, 122, 144 series-connected, 115 servo, 159 shunt-connected, 113 skewing, 125 thyristor drive, 134 time-constants, 108 torque and e.m.f. constants, 92 torque–speed calculation, 100 toy, 124 transient behaviour, 107
405
Damper, stepping motor, 335 Damping, synchronous motor, 349 Deep bar rotor, 214 Delta (mesh) connection, 172 Diode, freewheel or flywheel, 53 Direct on line (DOL) starting, 201 Discontinuous current, 139 Distortion, supply, 147, 378 Double cage rotor, 213 Double converter reversing drive, 146 Drive, d.c: armature voltage feedback, 155 chopper-fed, 155 control of, 148 current control, 150 general arrangement, 45, 148 IR compensation, 155 position control, 162 reversing, 144 servo, 159 speed control, 152 torque control, 155 Drive, inverter-fed induction motor: base speed, 285 closed-loop control, 293 comparison with d.c. drive, 280 constant-power and constant-torque, 288 control arrangements, 290 energy dump, 292 field-oriented (vector) control, 296 high-speed region, 289 motor waveforms, 282 open-loop speed control, 291 regenerative braking, 292 slip compensation, 293 starting torque, 287 steady-state operation - flux control, 284 torque–speed characteristics, 286 v/f ratio, 285 vector control, 296 voltage boost, 287 Duty cycle and rating, 376