Questions

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30 questions

• A single-phase fully controlled bridge feeds an inductive DC load. The current is continuous and the firing angle is increased from a small value toward 90 degrees. What happens t…

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Hard

• In a three-phase bridge converter, commutation overlap increases because source inductance is significant. What is the likely effect on average DC output voltage?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Hard

• A controlled rectifier's input power factor deteriorates as firing delay increases. What is the main explanation?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Hard

• A freewheeling diode is added across an inductive DC load supplied by a controlled rectifier. Which effect is expected during the freewheeling interval?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Hard

• A three-phase fully controlled bridge has a firing-angle control fault affecting one valve pulse. What is a likely consequence?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Hard

• In a line-commutated fully controlled converter, under ideal continuous-current conditions, the average DC voltage becomes negative when the firing angle is:

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Hard

• A single-phase fully controlled bridge operates with a sufficiently large continuous DC current. What does increasing firing angle generally do in rectifier operation below the in…

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Hard

• A controlled rectifier supplies a highly inductive load. Why may the output current be smoother than the output voltage?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Hard

• An ideal single-phase half-wave controlled rectifier feeds a resistive load from a sinusoidal source. If the firing angle is increased while the supply remains unchanged, what hap…

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Hard

• Which method is commonly used to control the output of a phase-controlled rectifier?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Medium

• What does the term overlap angle refer to in a line-commutated converter?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Medium

• Which issue is commonly associated with phase-controlled rectifiers?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Medium

• What is the role of a freewheeling diode in a controlled rectifier feeding an RL load?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Medium

• In a three-phase fully controlled bridge, how many SCRs are typically used?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Medium

• What is a key reason for using a three-phase controlled rectifier in higher-power applications?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Medium

• A centre-tapped single-phase full-wave controlled rectifier normally requires:

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Medium

• What is the main benefit of a fully controlled bridge rectifier compared with a half-controlled bridge?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Medium

• Why can an inductive load continue conducting after the supply voltage crosses zero?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Medium

• For a single-phase half-wave controlled rectifier with a resistive load, conduction begins when:

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Medium

• In phase control, what generally happens to the average output of a single-phase controlled rectifier when firing angle increases?

  Industrial Electronics & Control of Drives › Unit 2: Controlled Rectifiers · Medium