# Three phase rectification algorithm

Let's suppose we have a three phase rectifier like here:

https://www.youtube.com/watch?v=V6ZWYFTELQA

Now lets suppose we change diodes with transistors. Let's also put current probes on each of the three phases. Now we know exactly in which direction the current is flowing in each of the phases. Knowing this, what is the algorithm for opening/closing transistors, to keep the same operation as before with diodes?

• Possible duplicate of Three phase active rectification algorithm – uint128_t Jul 3 '16 at 19:27
• What is wrong with your other question on this topic – JonRB Jul 3 '16 at 19:49
• People are focusing on irrelevant stuff. – jurij Jul 3 '16 at 19:50
• The algorithm is: if the current goes forward, switch mosfet on. If the current is backward, switch it off. By the way, wouldn't it be simpler to just use comparators rather than a MCU? – dim Jul 3 '16 at 20:22
• Yes, but I have only phase current probes, not a current probe for each transistor. Lets say phase 1 current is positive, while phase 2 and 3 currents are negative. Which transistors need to be ON and which need to be OFF? By the way, you are correct, it would be simpler to use comparators, but this was already done by someone else. Also, it is much simpler to modify switching phase with MCU. – jurij Jul 3 '16 at 20:38