5/31/2014 4:25 PM | |
Posts: 22 Rating: (0) |
Dear Sir/Ma'm, Presently I am commissioning Low Voltage High Current Rectifier (having Hexa-Phase Transformer) with Third Party Bridge using Simoreg 6RA70 CM. Drawing of the same is enclosed. Input AC Voltage to Rectifier = 65 VAC (Coming from Hexa-Phase Transformer) Output DC Voltage from Rectifier = 45 VDC, Current = 8000 Amps Now I am checking the rectifier in open loop, connecting a 30 Ohm, 900 W resistor across DC output from bridge and Transformer Neutral (IPT) In this test I am changing the firing angle at P600 = K401, and K401 is varied from -60% to +60%. Accordingly the firing angle at r018 is also changing from 143.99deg to 30 deg. In this process the voltage is noted at r038. The output voltage is getting fixed at 13 VDC after r018 = 72 deg. The output voltage should reach around 45 V when r018 = 30 deg. But it is not happening. This is applicable for both the forward and reverse bridge. Measured Voltage between R+ and Y+, Y+ and B+, B+ and R+ / R- and Y-, Y- and B-, B- and R- = 65 VAC Measured Voltage between R+ and R- , B+ and B-, Y+ and Y- = 76 VAC (Is it correct ???) I am getting six lobes in CRO across the Resistor connected at DC though the six lobes are distorted little. 1. What may the possible reasons of voltage not build-up even if the firing angle at r018 shifts to minimum? 2. Is it because of some connection issue of the hexaphase system? If yes please suggest possible solution and how to detect the problem physically? 3. What is to be checked and rectified? Please provide possible solutions. Commissioning is in progess but held up due to this. Please suggest. AttachmentDrawing and Parameter Back-up.zip (252 Downloads) |
6/1/2014 6:15 PM | |
Joined: 8/25/2006 Last visit: 9/20/2024 Posts: 2209 Rating: (278) |
May be it is easier to ask the developer: Siemens VAI?
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