Questions

Multiple-choice questions you can practise one by one. Open a question, tap an answer and see at once whether it is right. For a random set, try Quick practice.

34 questions

• A chopper drive requires low output ripple at a given load and inductance. Which design change can often help, subject to switching-loss limits?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• A converter must provide variable-frequency AC from a DC source for an AC motor. Which topology is most directly suitable?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• A cycloconverter's output waveform contains significant low-order harmonics. Which design concern is most directly affected?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• A cycloconverter supplies a low-frequency motor load from a three-phase source. Why is output frequency usually limited to a fraction of input frequency in conventional line-commu…

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• For a dual converter, why must the firing controls of the two bridges be coordinated?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• A dual converter is operated in circulating-current mode. What component or arrangement is commonly used to limit circulating current?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• Compared with a square-wave inverter, PWM control can improve output waveform quality by:

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• In a series resonant inverter, the resonant circuit is important mainly because it:

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• A voltage-source inverter leg must avoid turning on both complementary switches simultaneously. Why?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• In a voltage-source inverter, why is a DC-link capacitor commonly used?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• A chopper switch operates at a fixed frequency. The on-time is increased while the total period remains constant. Which parameter increases?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• An ideal boost chopper operates from 100 V with duty cycle 0.5. Using Vout = Vin/(1-D), what is the ideal output voltage?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• A DC chopper has an ideal input of 200 V and a duty cycle of 0.35 in buck operation. What is its ideal average output voltage?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Hard

• Why are cycloconverters often associated with low-speed, high-power drives?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Medium

• What is the main function of a cycloconverter?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Medium

• Why may circulating current flow in a dual converter?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Medium

• What is the basic operating idea of a dual converter?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Medium

• What is one reason for using PWM in an inverter?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Medium

• Which statement best describes a current-source inverter?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Medium

• Which statement best describes a voltage-source inverter?

  Industrial Electronics & Control of Drives › Unit 3: Inverters, Choppers, Dual Converters and Cyclo-Convertors · Medium