help for DC motor controller

[Tair]

I need to build controller for DC motor 440V and 100 Amp. Can you help with diagramm?

 

[ronv]

Maybe a little more information:

You say 440 volts dc - does it get it's power from the 440 volt mains?

Only one direction?

 

[Ubergeek63]

I need to build controller for DC motor 440V and 100 Amp. Can you help with diagramm?

are you saying you have a 120A 440 service? At least a 3PH 50A 440V?

i do not think you want to know how much that entails. combined with regulations that are probably going to require power factor correction.

on top of that i kinda doubt it is a DC motor at that power level. BLDC perhaps but not DC.

 

[Tair]

Yes, this is from mains, 3PH. To feed DC motor on equipment. 40 KWt

 

[Tair]

Yes . its one direction.

 

[ronv]

Check out this link to see if this is what you need.

Variable-frequency drive - Wikipedia, the free encyclopedia

 

[Reloadron]

Been awhile but you are looking at a circuit similar to the attached to use one as an example. These are big SCRs for DC motors of high HP used in industrial applications. I remember circuits like the attached as well as circuits using large mercury arc rectifier tubes. The attached is rough and does not contain the SCR firing circuit but something along those lines is what you want for a 100 Amp 440 volt DC motor. SCRs like these have big heat sinks and forced air cooling. You also may want to look at thyristor circuits.

Unfortunately you don't provide details on the DC motor? Like how it is wound.

Ron

 

[ronv]

Gonna take a lot of courage to throw that switch.

 

[Reloadron]

Gonna take a lot of courage to throw that switch.

LMAO, actually they aren't all that bad. Generally you ramp the motor up to speed. The SCRs in them resemble a hockey puck. Then you have some large diameter cables for 100 amp service. I don't see as many large DC motors as I once did but I once saw like a 500 HP DC motor. Biggest motors I deal with today are 25 to 40 HP 480 VAC 60 Hz. motors and then only once in a while. Still don't know exactly what type DC motor the OP has so it's really hard to suggest much. However, motor controllers like that you generally buy a commercial drive for. Rockwell Automation and Reliance Electric come to mind.

Ron

 

[Tair]

Been awhile but you are looking at a circuit similar to the attached to use one as an example. These are big SCRs for DC motors of high HP used in industrial applications. I remember circuits like the attached as well as circuits using large mercury arc rectifier tubes. The attached is rough and does not contain the SCR firing circuit but something along those lines is what you want for a 100 Amp 440 volt DC motor. SCRs like these have big heat sinks and forced air cooling. You also may want to look at thyristor circuits.

Unfortunately you don't provide details on the DC motor? Like how it is wound.

Ron

thanks for this, but how control the motor freq.? to switch off some rectifiers?

 

[Tair]

LMAO, actually they aren't all that bad. Generally you ramp the motor up to speed. The SCRs in them resemble a hockey puck. Then you have some large diameter cables for 100 amp service. I don't see as many large DC motors as I once did but I once saw like a 500 HP DC motor. Biggest motors I deal with today are 25 to 40 HP 480 VAC 60 Hz. motors and then only once in a while. Still don't know exactly what type DC motor the OP has so it's really hard to suggest much. However, motor controllers like that you generally buy a commercial drive for. Rockwell Automation and Reliance Electric come to mind.

Ron

This motor is used in sausage cutter Zeydelmann. Its actually not working properly, at only one fixed frq 1500 RPM. I thought to build quickly PWm controller on thyristors

 

[Reloadron]

thanks for this, but how control the motor freq.? to switch off some rectifiers?

You said it was a DC motor. There is no frequency exactly. You may be able to use PWM. However you haven't said how this motor is wound (configured). Like, how many wires exit the motor frame? How was it previously speed controlled? This must be an awfully large sausage cutter if it was powered by 440 Volts at 100 Amps. There are several ways to control speed of a large DC motor and the type motor plays a roll in the speed control.

Ron

 

[Tair]

You said it was a DC motor. There is no frequency exactly. You may be able to use PWM. However you haven't said how this motor is wound (configured). Like, how many wires exit the motor frame? How was it previously speed controlled? This must be an awfully large sausage cutter if it was powered by 440 Volts at 100 Amps. There are several ways to control speed of a large DC motor and the type motor plays a roll in the speed control.

Ron

Thank you, Ron. It is DC motor. It has 4 wires. No idea of what exactly type of DC motor this is. And of course no frequency exactly its open-close implulse but I checked link and found VFD contoller needed. What easiest way to control?

 

[Reloadron]

Note:

A variable-frequency drive (VFD) is a system for controlling the rotational speed of an alternating current (AC) electric motor by controlling the frequency of the electrical power supplied to the motor.[1][2][3] A variable frequency drive is a specific type of adjustable-speed drive. Variable-frequency drives are also known as adjustable-frequency drives (AFD), variable-speed drives (VSD), AC drives, microdrives or inverter drives. Since the voltage is varied along with frequency, these are sometimes also called VVVF (variable voltage variable frequency) drives.

The units you refer to are for an AC motor and not a DC motor. You said you have a DC motor?

OK, you have 4 wires exiting the frame. Are they labeled? Anything like A1, A2 and F1, F2? You need to know exactly what you have before you worry about controlling the speed of it. Again, look at the wires exitio9ng the case. Are they all the same wire gauge or are there two heavier than the other two? Have you taken resistance readings of the wores?

Ron