Power Electronics Component Information about Chopper | Classification of Chopper | Principle of Operation | Application | Strategies of chopper

 

What is Chopper

In this blog we discusses about an most important Power electronics component, Chopper.

Chopper is a power Electronics device or component. It is a HIGH speed ON/OFF Semiconductor Switch. Chopper convert DC to DC but the output is Controlled.

The chopper are classified into different type. There are various application of Chopper. Now we discusses about Principle of Operation of chopper, Classification of chopper, Control Strategies application of chopper. So let’s start.

Basic Principle of Operation of Chopper:

In general, A Chopper is a high-speed ON/OFF semiconductor Switch. Chopper disconnects the load from source and again connects the source to load at high-speed.

This operation is achieved by continuously triggering ON and triggering OFF the chopper by using the power switch (SCR) at rapid speed.

The duration for which the power switch (SCR) is remains in ON state, it’s called ON time.

The duration for which the power switch (SCR) is remains in OFF state, it’s called OFF time.

 The average voltage across the load can be varied by varying the ON time and OFF time of the SCR

 

 

Classification of Choppers

Basically there are two types of choppers :

•    Step-up choppers (output voltage is more than input voltage)
•     Step-down Choppers (output voltage is less than input voltage)

Choppers are classified based on different ways, such as

Based on input/output voltage levels

1. Step-up Chopper (Boost Converter)
2. Step-down Chopper (Buck Converter)
3. Buck Boost Converter

Direction of output voltage and current

• Class A
• Class B
• Class C
• Class D
• Class E

Based on Circuit operation 

1. First(single) Quadrant Chopper
2. Two-quadrant Chopper
3. Four Quadrant Chopper

Based on Commutation Method

1. Voltage Commutated Chopper
2. Current Commutated Chopper
3. Load Commutated Chopper
4. Impulse Commutated Chopper

 

Control strategies of chopper:

If you want to get controlled DC output then you must have to controlled the chopper. The output of chopper can be controlled by these methods. Such as

• PWM Control
• Variable frequency Control.
• Current Limit Control

 

PWM Control

You can control the Chopper by using PWM method. You can control the output of chopper by varying the ON-time or OFF-time of input.

Chopping period ‘T’ is Constant and On-time(t_on) is varied keeping chopping frequency ‘f  ’

Due to varying the ON-time (t_on), the output voltage is varying.

Comparison of Control Strategies of chopper in Power Electronics

Thank you.

Share the blog to Support