3-phase TR rectifier I/O controller design - Page 1
Forum section: electronics / projects

author: Md Mubdiul Hasan
author_rank: Regular Contributor
timestamp: May 29, 2018, 01:32:33 am
content: Hi there,I have been back to high power design.My system contains 3phase, 380V, 50Hz ac input, secondary surge protector, Aux Tr ( single phase, 380V/220V, 300VA), phase transformer( 3ph, 380v/12v,0v,12v,100VA) and a main transformer ( 3ph, 380V/9V,18V,800VA),SCR(1600V, 50A) bridge, DC reactor( DC 20V,20A). Rectifier output should be DC 20V 20A.My requested EVM should be,1. PTR secondary windings phase, amplitude and rating controller.2. MTRs secondary fuse (690V, 32 A) sensing3. SCRs switching controller.4. 50mlV, 30A shunt sensing,5. GPS communication,6. RSM7. LAN8. Display....etc,Kindly recommend me one.You can also transfer this post to suitable forum.Regards

author: oldway
author_rank: Super Contributor
timestamp: May 30, 2018, 10:01:09 am
content: 400W, I do not find it is high power.I did a similar project (1 -> 4) in 1982 but it was for much higher powers (330V 600A)Such a technology is currently totally out of date and could no longer apply, except for very high powers.Also, I doubt that you find a solution to your question.A small note about the use of a 50 mV shunt: if you choose a full bridge (6 x SCR's) without freewheeling diode, you can use 2 current transformer mounted in open triangle + 3ph rectifier to measure the current, it's much more reliable.

author: Md Mubdiul Hasan
author_rank: Regular Contributor
timestamp: May 31, 2018, 01:15:03 am
content: QuoteI was considering AC inputs also, not output DC.You know this project looks like a converter.QuoteNot sure what your mathematical notetaion means! Are you talking about turns ratio?QuoteI think main principles are same, just need electronic control through MCU and DSP.Let me know any recent technology.QuoteI am using 3 SCR with free wheeling diodes as well.

author: oldway
author_rank: Super Contributor
timestamp: June 01, 2018, 09:27:56 am
content: (1->4) means points 1 to 4 of your request.The choice between the 3 SCR 's circuit and 4 diodes and 6 SCR' s had been analyzed in 1982 and the choice was for 6 SCR's for 3 reasons:- frequency ripple 6x the network frequency instead of 3x- possibility of recovering the energy of the inductor towards the network, which makes the control more rapid during the decrease of the output current- possibility of measuring the current dc from current transformers.This same choice is found on all three-phase thyristor drives for DC motors, which confirms the accuracy of this choice.The project I developed in 1982 was for industrial battery chargers and used TCA780s (replaced by TCA785 later) and had several cards with:1) power supplies + automatic recharge2) control3) pulse generation + synchronisation filters4) fault signaling5) interface with insulation6) card with snubber and pulse transformer (1 per thyristor)7) fuse opening detection cardUsing mostly OP's and Cmos logic.EDIT: as I wrote, such a technology is currently totally out of date and could no longer apply, except for very high powers.Using it for a 20V 20A power supply is non sense !!!!Use a 3 phase bridge rectifier with a buck converter.

author: Md Mubdiul Hasan
author_rank: Regular Contributor
timestamp: June 05, 2018, 06:26:37 am
content: Nice to get your response Sir Oldway!QuoteCan you give me any related publication to better understanding, why dont we try with 3 SCRs for minimizing the cost? Hence also give some documents that why we use SCR instead of diode!QuoteDo you want me to read this paper,https://ieeexplore.ieee.org/document/6119397/I think I need more perfect one, because gate driver should control by a smart DSP/MCU. Few factors might be arise, 1. Fire angle controle 2. Phase control 3. Zero crossing controlQuoteI see, now a days all can be manage by single ARM core.QuoteEven it looks silly, but somehow real world demand is noticiable.QuoteKindly give me a reference.

author: Md Mubdiul Hasan
author_rank: Regular Contributor
timestamp: June 12, 2018, 02:18:46 am
content: Dear Sir Oldway,Did you make a device like below,