What does it mean by these terms : DC Reactor Connection, Braking Resistor Connection

[danishdeshmuk]

What does it mean by these terms :

DC Reactor Connection, Braking Resistor Connection & Braking Unit Connection ?

What is DC Reactor ? With what components its made up of ?

What is Braking Unit ? With what components its made up of ?

What is Braking Resistor ? With what components its made up of ?

External Dynamic Braking Resistor Vs. Internal Dynamic Braking Control Circuit ?


thanks

 

[mister_rf]

Read here:
https://www.ab.com/support/abdrives/documentation/techpapers/RegenOverview01.pdf

DC reactor = DC choke
This is used to improve the input power factor of the inverter power supply and reduce harmonics. The ''DC reactor'' is more effective than the input reactor in improving the power factor

Optional devices | TOSHIBA INVERTER | TOSVERT VF series

Braking resistor
This operation is used when sudden deceleration or stops are frequently performed, or when the deceleration time must be shortened on loads having a large inertia. This resistor is for taking up energy during power generation braking.

Optional devices | TOSHIBA INVERTER | TOSVERT VF series

 

[danishdeshmuk]

thanks for your reply but what about other questions asked in this post like:

With what components DC Reactor made up of ?

What is Braking Unit ? With what components its made up of ?

With what components Braking Resistor made up of ?

Difference in between "External Dynamic Braking Resistor" Vs. '"Internal Dynamic Braking Control Circuit" ?

Also, Difference in between "AC Reactor (Choke)" Vs. "DC reactor (Choke)" ?

thanks bundle of

 

[mister_rf]

Essentially a reactor is an inductor, so is simply a coil of wire wrapped around a laminated steel core that allows a magnetic field to form around the coil when current flows through it. Either AC reactors or DC reactors (link chokes) serve the same primary purpose, to smooth the current flow to the inverter/converter, and reduce damaging harmonics produced on the power lines.
-AC reactors are placed in series with the incoming AC power line. They have advantage to provide some protection from voltage transients created by power factor capacitor switching and lightning surges because they are installed before the input diodes. As disadvantage they may cause a voltage drop to the converter due to a condition called overlap of diode conduction. (This effectively short circuits the AC supply through the rectifier impedance, as one diode continues to conduct while another one starts conducting. This creates distinct notches on the supply voltage) Read additional details here:
**broken link removed**
http://scholar.lib.vt.edu/theses/available/etd-173510281975580/unrestricted/chapter2.pdf

-DC reactors (link chokes) are connected after the input diodes in the power circuit. One of the disadvantage of the DC reactors is they are located after the input diodes, and do not protect the diodes from possible voltage transients. One coil is needed in a DC circuit versus 3 coils in the AC circuit. Additionally DC reactors smoothing the current flow limits the high peak current pulses from abusing the capacitor bank inside the converter.

 

[danishdeshmuk]

Essentially a reactor is an inductor, so is simply a coil of wire wrapped around a laminated steel core that allows a magnetic field to form around the coil when current flows through it. Either AC reactors or DC reactors (link chokes) serve the same primary purpose, to smooth the current flow to the inverter/converter, and reduce damaging harmonics produced on the power lines.
-AC reactors are placed in series with the incoming AC power line. They have advantage to provide some protection from voltage transients created by power factor capacitor switching and lightning surges because they are installed before the input diodes. As disadvantage they may cause a voltage drop to the converter due to a condition called overlap of diode conduction. (This effectively short circuits the AC supply through the rectifier impedance, as one diode continues to conduct while another one starts conducting. This creates distinct notches on the supply voltage) Read additional details here:
**broken link removed**
http://scholar.lib.vt.edu/theses/available/etd-173510281975580/unrestricted/chapter2.pdf

-DC reactors (link chokes) are connected after the input diodes in the power circuit. One of the disadvantage of the DC reactors is they are located after the input diodes, and do not protect the diodes from possible voltage transients. One coil is needed in a DC circuit versus 3 coils in the AC circuit. Additionally DC reactors smoothing the current flow limits the high peak current pulses from abusing the capacitor bank inside the converter.

You explained almost everything but left this question unanswered .......
Difference in between "External Dynamic Braking Resistor" Vs. '"Internal Dynamic Braking Control Circuit" ?

 

[FvM]

My understanding ís this: You need both a braking control circuit (particalurly a DC switch) and a braking resistor to perform dynamic braking. There's no reasonable question about the difference, one won't work without the other.

 

[mister_rf]

"External Dynamic Braking Resistor" Vs. '"Internal Dynamic Braking Control Circuit"…….


When electric motor-driven machinery is stopped energy is created, which can be regenerated into the drive system through the motor itself acting as a generator. This braking energy needs either to be put back into the power supply or dissipated as heat. This series circuit is placed across the DC bus and is often called:

1) “Chopper”
or
2) “Dynamic Brake” = "Internal Dynamic Braking Control Circuit"

The major difference Dynamic brake vs Chopper is in the construction.

1) Dynamic brakes have the controller, switching device and resistor (Internal Dynamic Brake Resistor) housed in one self contained unit.

2) A chopper contains only the regulator circuit and switching device and is rated in amps. The resistors >> "External Dynamic Braking Resistor" are treated as a separate component. In this case the resistors can be accurately sized for a given application and the chopper module can be mounted in an enclosure while the resistor, with the large amount of heat energy to dissipatecan be remotely mounted.