I am (for educational and research purposes) trying to replace diodes with MOSFETs in a rectifier of a conventional automotive alternator (12V).

Before I proceed with hardware implementation, I would like to learn as much as possible about rectification itself and also synchronous rectification. I would like to know which parameters (hardware and software) affect parameters like efficiency and similar. I would also like to study how different MOSFET timing affects the rectification.

Can somebody suggest a good simulation software for a start? Also any advanced literature would be welcomed.

  • \$\begingroup\$ LTSpice is a decent free simulator. \$\endgroup\$ – Peter Oct 12 '15 at 21:12
  • \$\begingroup\$ If I google "synchronous rectification" I find at least half-dozen appnotes... and a PhD thesis on the first couple pages of hits (never mind the Wikipedia page). Alas on EE.SE book and software recommendations are off-topic. \$\endgroup\$ – Fizz Oct 12 '15 at 21:18
  • \$\begingroup\$ Yes, but all of these appnotes are mostly dealing with synchronous rectification in DC/DC converters ... while I would like to rectify 3-phase (distorted) sine voltage. \$\endgroup\$ – jurij Oct 14 '15 at 18:40
  • \$\begingroup\$ FYI, Infineon uses Synopsys' Saber (not PLECS) for integrated thermal-electrical modeling (besides SPICE). You can search around to see what other big semicon manufactures use for power electronics. \$\endgroup\$ – Fizz Oct 15 '15 at 10:13

LTSpice IV is an excellent simulation tool provided free of charge by Linear Technology.

It is widely used- students use it for research and homework, many companies (including GE) use it to simulate power electronics- motor drives, dc/dc converters, wind inverters, you name it.

PLECS is probably the best tool nowadays but it is not free.

While synchronous rectification is quite simple to grasp, it can be difficult to implement. Timing is crucial. Lots of research was done on driving the SR gates with the same signals as the main power switches.

A good app note is here: http://www.ti.com/lit/an/snva595/snva595.pdf

The issue with high-speed SR lies in parasitic circuit inductances, which tend to offset the turn-on of the rectifying device and hence increase losses, driving the need for increased heat-sinking properties.

Unless your application is very high-speed or high-voltage isolated (where you need to account for the opto-coupler delays), the implementation of synchronous rectification should be quite easy.

I have attached a couple of slides on SR from my university.

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  • \$\begingroup\$ Thanks. I've read the application note and everything is pretty clear to me ... but it is missing one particular field which I am interested about - transistor timing. If I quote: "Ensuring the proper timing of the gate drive signals for the SRs is an important task that designers must address to maximize converter performance." Do you maybe know where to find more info about this? Thanks! \$\endgroup\$ – jurij Oct 14 '15 at 18:52
  • \$\begingroup\$ @jurij This chapter of a VT dissertation has some nice graphs of SR : scholar.lib.vt.edu/theses/available/etd-173510281975580/… (VT is considered the world's best school for power electronics). A little bit on timing can be found here as well: m.eet.com/media/1142502/51602di.pdf \$\endgroup\$ – SunnyBoyNY Oct 14 '15 at 19:40

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