A 2-pole, three-phase, star-connected permanent magnet brushless dc drive has a phase inductance of 20 mH...

 

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A 2-pole, three-phase, star-connected permanent magnet brushless dc drive has a phase inductance of 20 mH per phase. The induced voltage per phase developed at 1000 rpm is found by experiment to be 41.7 V rms. A resolver is used in a closed-loop control scheme such that the torque angle ß is maintained at 90° . The inverter has a maximum output voltage of 346 Vrms (line) and a maximum current rating of 10 A rms. Calculate the current and power factor when: (i) the drive develops 1 kW at 3000 rpm. (ii) the drive develops 3 kW at 3000 rpm. (iii) Calculate the maximum speed at which the maximum current can be supplied to the motor. (iv) What is the maximum no-load speed if the control strategy is maintained? (v) What strategy may be used above this speed? A 2-pole, three-phase, star-connected permanent magnet brushless dc drive has a phase inductance of 20 mH per phase. The induced voltage per phase developed at 1000 rpm is found by experiment to be 41.7 V rms. A resolver is used in a closed-loop control scheme such that the torque angle ß is maintained at 90° . The inverter has a maximum output voltage of 346 Vrms (line) and a maximum current rating of 10 A rms. Calculate the current and power factor when: (i) the drive develops 1 kW at 3000 rpm. (ii) the drive develops 3 kW at 3000 rpm. (iii) Calculate the maximum speed at which the maximum current can be supplied to the motor. (iv) What is the maximum no-load speed if the control strategy is maintained? (v) What strategy may be used above this speed?

Answer rating: 100% (QA)

i To calculate the current and power factor when the drive develops 1 kW at 3000 rpm we can use the following steps Step 1 Calculate the phase voltage at 3000 rpm The induced voltage per phase is give... View the full answer