PWM Boost Rectifier Circuit

[maheshwaran]

Any one have an idea about PWM Boost Rectifier and also IGBT STGIPL14K60 Intelligent Power Module.

Thank you,
Maheshwaran

 

[FvM]

The voltage control loop is missing from the block diagram.

 

[maheshwaran]

Thanks for your reply. Can you suggest reference for me to understand the circuit better.

 

[FvM]

Google for "active front end rectifier" or "active front end inverter"

 

[maheshwaran]

Sir I have doubt in basic operations in the circuit because it contains parallel combination of igbt and diode Sir. So please suggest the reference which contains explanation of one full cycle of input waveform.

 

[FvM]

It's a basic three-phase bridge which should be explained in any power electronics text book.

Depending on the switch state and instantaneous current polarity, the current in each phase is either carried by an IGBT or a diode. That's not specific for the active front end rectifier application, you have the same situation e.g. in a motor inverter.

 

[maheshwaran]

Sir I had an doubt that it is act as a normal 3 phase diode bridge rectifier(for ac to dc side) and igbt inverter(for dc to ac) is it right sir?

 

[FvM]

Sir I had an doubt that it is act as a normal 3 phase diode bridge rectifier(for ac to dc side) and igbt inverter(for dc to ac) is it right sir?

It's definitely not right. Or let's say, it's right in so far that the circuit acts as a rectifier when all IGBTs are off. But that's not the intended circuit operation.

Consider that the bridge is controlled in a synchronous PWM scheme, means each phase is either switched to DC- or DC+ at a time. Usually a three-level PWM scheme is implemented, as for a motor inverter. To visualize the inverter operation, you can imagine a single phase (H-bridge) topology.

You have an AC source connected through a series inductor to the H-bridge. There are basically two phases of boost operation.
1. Both H-bridge sides are switched to the same DC bus node, either D+ or DC-. The input source is "shorted" by the inductor, current is increasing and energy stored into the inductor.
2. The H-bridge sides are switched to opposite DC nodes. The instantaneous AC voltage is smaller than the bus voltage, the inductor current is decreasing, energy is transferred from the AC source and the inductor to the DC bus.

You can also take a time-averaged view point. Imagine the inverter as a synchronous machine (acts both as motor and generator). The inverter is modulated with a sine voltage a bit lower than the AC input. Thus there will be an energy flow towards the inverter. As with the synchronous machine, phase and magnitude have to be controlled in a way that the intended current and energy flow is achieved.

 

[maheshwaran]

Thank you sir. Please suggest some reference for single phase pwm boost rectifier sir.