HVDC Motor Direction changing

[anandaraj]

Hai friends...

Currently i am trying to change the direction of the HVDC (230 VDC,2A) motor during running time. I required the forward run for first 30 seconds then reverse run for next 10 seconds .

Queries:
1.Is relay based switching might helpful?
2.For sudden forward to reverse change Arc problem will occur or it is no problem?
3.Without using controller, fully electrical control is possible ?

kindly guide me.

 

[chuckey]

1. If the time period is not critical, relays would work but time could be +- 5mS.
2. Back EMF suppression will be a problem what ever form of control you use, relays are more forgiving the transistors, and if plug in are easier to change. Just remembered, switching DC with relays puts extra strain on their contacts as the arc is not self extinguishing. Relays that are rated at 2A @230V AC are rated at 12/24 V DC, so finding a sufficiently rugged relay, for a long life could be a problem.
3. A couple of NE555 timers would do the job for the timing and both time periods could be adjusted for optimum performance and some form of interface to power the main relay (s)
The system has to be fully specified, i.e. when you apply power what happens, when you switch the motor on what happens, which direction it runs in, emergency stop, etc.
Frank

 

[anandaraj]

Dear Chuckey,

Thank you for your kind response. I have answered few of your questions below.

1.Time is not a problem.(+-5 ms is ok)
2.I have attached a simple circuit with on/off sequence.kindly verify, it will work or not.(additionally Any arc protection required for this circuit)

https://obrazki.elektroda.pl/index.php

3.I am not thinking now about Relay triggering ( With NE 555 or controller)
4.Whenever applying power, it will rotate FW run for some time then it will rotate reverse run (Here relay switching to be done for our required sequence).This sequence will follow untill the main power will switched off.

- - - Updated - - -

Dear Chuckey,

I have missed few points to add.That i have listed in below.

1.I have connected the relay before rectification.Reference image is given in below link.
https://obrazki.elektroda.pl/6769604500_1428054314.html.

2.For AC switching 230VAC @ 2Amps Relay is enough or rating should be increased.