DC motor control for test bench

[Mancunian69]

Hi, I have in my garage a dc motor.
Here are the specs:

200vdc
1hp
6A
2800rpm

I want to build a speed controller for it safely packaged in a plastic case.
What is the best way to go about it. I need to know what parts to buy in oder to take the mains, rectify it to make the motor infinitely variable speed.

The motor will be used for driving motorcycle engines on test bench before isntallation.

I am aware that this voltage is dangerous but have though about alternatives, such as treadmill motor or a washing machine motor or lower votalge dc motor.
I know virtually nothing about speed control.

I need your help guys.

 

[cl10greg]

Well with power at that range you are going to want safety redundancy. I would first implement a contactor/relay that activates the system and can be switched off for deactivation. Also, fusing and fail safes in a lot of locations. The controller depends on how you want the operation. If you want forward and reverse direction you are going to need to buy or build an H-bridge. If you only need one direction with variable speed, you can get away with half an h-bridge.

So essentially when you are going to be doing is getting a signal from a variable voltage source to control your speed. I have used a spring loaded potentiometer that I created to change the resistance to simulate throttle. This signal is going to feed into your microcontroller and produce an PWM signal. The PWM should ramp up and not be instantaneous to limit the inrush current and save you controller. At this point you could try a motor driver IC but at that voltage you are going to have to pay an crazy amount of money. At the same time, you're now risking dangerous voltage experimentation so be mindful. The system you want to build needs to be able to handle at least 250VDC and 12A. You want to oversize for transients and other system responses. You can either buy a low side drive and a high side drive seperate or you can do it together. You will just be looking into the the drivers to drive external mosfets (or IGBTs) to run your motor. Your PWM signal will run the drivers that will run the motor. You are going to want to find transistors with low Rds(on) values. The lower the RDS(on) the less heat it will produce. You are also going to have to time your controller to have safe dead time if you are using different high side and low side drivers. Most HSD and LSD also have some current sensing capability that is a good idea to look at while running the system.

Don't forget to use flyback diodes for the FETs because of back EMF.

Sorry for the quick run through. Let me know what some more of your questions are.

 

[goldsmith]

Hi, I have in my garage a dc motor.
Here are the specs:

200vdc
1hp
6A
2800rpm

I want to build a speed controller for it safely packaged in a plastic case.
What is the best way to go about it. I need to know what parts to buy in oder to take the mains, rectify it to make the motor infinitely variable speed.

The motor will be used for driving motorcycle engines on test bench before isntallation.

I am aware that this voltage is dangerous but have though about alternatives, such as treadmill motor or a washing machine motor or lower votalge dc motor.
I know virtually nothing about speed control.

I need your help guys.

Hi Mancunian69

For this kind of DC motor that is simple you must change the voltage across the motor or change the current .
How ?
First of all i must ask you are you familiar with PWM and PWM drivers ?
Or perhaps a better question , do you want the circuit diagram or perhaps you want to be guided to design your own circuit ?

i can help you in either ways .

Merry Christmas + Best Wishes
Goldsmith