Current mode control in Power Electronics - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is current mode control in power electronics?

Current mode control is a technique used in power converters where the output current is directly controlled to improve performance and stability.

beginner

Why is current mode control preferred over voltage mode control in some applications?

Because it provides faster response to load changes and better protection against overcurrent by directly regulating the current.

intermediate

What are the two main loops in a current mode control system?

The inner current loop that controls the inductor current and the outer voltage loop that regulates the output voltage.

intermediate

How does current mode control improve converter stability?

By using the inductor current as a feedback signal, it reduces the effect of input voltage variations and load disturbances, stabilizing the system.

advanced

What is the role of the slope compensation in current mode control?

Slope compensation is added to prevent subharmonic oscillations when the duty cycle exceeds 50%, ensuring stable operation.

What does current mode control directly regulate in a power converter?

A Output current

B Output voltage

C Input voltage

D Switching frequency

Current mode control directly regulates the output current by controlling the inductor current.

Which loop in current mode control manages the output voltage?

A Outer voltage loop

B Input voltage loop

C Inner current loop

D Frequency loop

The outer voltage loop regulates the output voltage by adjusting the current reference.

What problem does slope compensation solve in current mode control?

A Overvoltage protection

B Subharmonic oscillations

C Thermal runaway

D Input voltage ripple

Slope compensation prevents subharmonic oscillations that can occur at duty cycles above 50%.

Which of the following is an advantage of current mode control?

A Slower response to load changes

B Direct control of output voltage

C Faster response to load changes

D No need for feedback loops

Current mode control offers faster response to load changes by directly controlling the current.

In current mode control, what is typically measured to provide feedback?

A Switching frequency

B Input voltage

C Output voltage

D Inductor current

The inductor current is measured and used as feedback in current mode control.

Explain the basic working principle of current mode control in power converters.

Think about how current and voltage are controlled in two loops.

Describe why slope compensation is necessary in current mode control and what issue it prevents.

Consider what happens when the duty cycle is high.