Power Electronics Problem Set 2a

This video tutorial covers the analysis of switching and conduction losses in different circuits. It emphasizes understanding the concepts rather than just solving problems. The tutorial includes three main problems: calculating losses in a resistive load circuit, analyzing conduction losses in an inductive load, and determining total losses in bridge switching devices. The video also discusses the importance of thermal resistance in maintaining device temperature. Key concepts include switching and conduction losses, resistive and inductive loads, and thermal management.

What is the main objective of the tutorial session?

• To memorize the solutions to the problems

• To focus on the thermal resistance calculations

• To understand the concepts of switching and conduction losses

• To learn how to manipulate circuit questions

In Problem #1, what is the frequency of the switch operation?

• 20 kHz

• 15 kHz

• 25 kHz

• 10 kHz

What is the total power dissipation calculated in Problem #1?

• 11.5 watts

• 10 watts

• 9.75 watts

• 8.98 watts

What is the thermal resistance required to maintain the device case temperature below 80 degrees in Problem #1?

• 7 Celsius per watt

• 4 Celsius per watt

• 5 Celsius per watt

• 6 Celsius per watt

In Problem #2, what is the duty cycle of the transistor?

• 30%

• 60%

• 40%

• 50%

What is the modeled current source value for the inductive load in Problem #2?

• 4 A

• 5 A

• 7 A

• 6 A

In Problem #3, what is the frequency of the square wave output produced by the inverter?

• 6 kHz

• 7 kHz

• 5 kHz

• 4 kHz

What is the total power loss in the bridge switching devices in Problem #3?

• 96 watts

• 76 watts

• 86 watts

• 66 watts

What is the average voltage across the load in Problem #3?

• 0 volts

• 150 volts

• 600 volts

• 300 volts

In Problem #3, what is the thermal resistance required for the heat sink?

• 0.42 Celsius per watt

• 0.52 Celsius per watt

• 0.62 Celsius per watt

• 0.72 Celsius per watt