High-power high-end switching power supply

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High-power high-end switching power supply [Copy link]

DC output 48V/70AWith 350V/10ATwo types: 3500W and 48V/112AWith 350V/17AThe circuit design and component application characteristics of two 6000W high-end switching power supplies are analyzed, and some issues that need further analysis are proposed.

In July 2001 , a power supply technology enthusiast sent me two high-end power supplies that were said to be " military top secret grade " , hoping that I could do a special dissection and in-depth analysis in order to digest and absorb their advanced technology.

The nameplate on the iron shell of the power supply indicates that it is IBM 's "Bulk" power supply specifically for large ships.

One is DC output 48V/70ALong communication power supply, length × width × height =70cm×22cm×12cm, weight approx.14kgGrid input three-phase 380 ~ 415V (current13A), or you can reduce the input to 200 ~ 240V (current24A), frequency 50 ~ 60Hz . This power supply is equipped with an electric fan for forced air cooling, and a three-phase high-voltage large switch is installed on the casing. The grid input is first filtered by a large shielding box.

The other is DC output 350V/10AShort special power supply, length × width × height =40cm×30cm×8cm, re-contract10kg, no forced air cooling, and the heat sink is also shorter. The nameplate on the iron shell indicates that it is a three-phase input of the power grid, with three input ranges: 200 ~ 240V , 380 ~ 415V , 460 ~ 480V . When the voltage is low, I _IN =25A( MAX ); its output DC is 350V/12.5A( MAX ). Grid frequency 50 ~ 60Hz .

The first step of the dissection work is to desolder the high-power components on the two (two) power supply motherboards. There are three types in total:

1 ) The heaviest large magnetic components are the main power transformer and Boost energy storage inductor, and 5 iron powder core magnetic toroidal inductors ;

2 ) Large MOSFET , IGBT power switch modules, and two grid rectifier modules P425, etc.;

3 ) Large-sized high-voltage aluminum electrolytic capacitors (4 pcs 940μF/450V) , 2 pcs 220μF/450V ), and several CBB high-frequency, high-voltage, non-inductive, non-polar polypropylene large capacitors, all of which are high-quality surge absorption components.

2.1 IR 's power devices

First of all, what surprised me was that the product model markings of the MOSFET and IGBT large modules, which are all trademarks of IR Company , were replaced by fake codes, which could not be found in IR Company's thick product manuals.

1) A module with an IGBT and a diode inside is pasted on the side wall , labeled "F530 ( 9604 ) " , "F826 ( 9615 ) " , "F1670 ( 9726 ) " , "F4702 ( 9845 ) " , etc.

2 ) Judging from the circuit, it is a module with a MOSFET and a diode inside, labeled "M4005 ( 6315 ) " , "M4427 ( 9624 ) " , "M3422 ( 9611 ) " , etc.

3 ) Judging from the circuit, it is a module with two MOSFETs (half-bridge dual-tube), labeled "M5220 ( 9708 ) " , "M5662 ( 9726 ) " , "M3419 ( 9603 ) " , "M6768 ( 9814 ) " , etc.

This special shell has never been seen on the market, and each weighs nearly100gEach power supply uses 4 MOSFET modules, and the copper block on the top of the heat sink is as thick as6mm, length × width =9.2cm×2cm. The 48V power supply has exploded.

4 ) The main chip on the PFC control board is marked as "53H1747”, all 4 power supplies are the same, it should be UC3854 .

I first took 8 to 9 IR MOSFETs and IGBTs that I had unsoldered to the IR Shenzhen branch to ask the technicians for identification. The technicians said that they were " military top secret " products, not industrial civilian products, so they were not listed in the manual. According to the 3500W power supply analysis, the reverse withstand voltage of the MOSFET should be 500V to 600V , and the working current should be30A~40A. Since the IR agent confirmed that the large high-frequency switch tubes used on the motherboards of these two high-power power supplies were high-end products specially made for military equipment, they were replaced with fake codes for confidentiality. Therefore, it is worthwhile to carefully and meticulously dissect, measure and analyze the two 3500W power supplies in depth. Later, I checked the side wall trademarks of MOSFET and IGBT modules on the motherboards of several opened power supplies at the supplier several times , and recorded the main symbols in detail. Only then did I discover that the special MOSFETs of IR's factory in Mexico ( MADEINMEXICO ) concealed the following important marks:

——All those marked with "82-5039 + " at the bottom , no matter how the false code changes, are half-bridge dual-tube MOSFETs , such as "M7471 ( 9846 ) " , "M3937 ( 9613 ) " , "M3438 ( 9602 ) " , "M5706 ( 9732 ) " , "M3467 ( 9602 ) " ;

——All those marked as "82-6252 + " at the bottom , no matter how the false code is changed, are single-tube MOSFET plus a diode, such as "M7453 ( 9845 ) " , "M4045 ( 9616 ) " , "M3721 ( 9609 ) " , "M5394 ( 9714 ) " , "M3161 ( 9547 ) " , "M3453 ( 9602 ) " , etc.