Indirect Frequency Converter

Indirect frequency AC-AC converter with some filtering in the intermediate circuit. LEFT SIDE rectifies 325V AC 50Hz to 685 DC (without load). MIDDLE PART (the 100mH inductor & 100uF capacitor) has a switch you can play around with to add/remove the filtering inductance. RIGHT SIDE (the transistors) has a DC-AC converter with the output connected to a 3 phase RL load. The output frequency here is a fixed 105Hz (random value I picked), but can be changed by editing the period of all 6 voltage sources (1000 / 9.5ms = 105.26Hz). I might try to add an actual driving circuit where you can set the output frequency in a future update. By default ORANGE is graphing the input current and GREEN is graphing the output current. Ignore the relays at the top. That's just there to get rid of the annoying 10A+ current spikes at the start of the simulation (I am ensuring a non-zero voltage on the capacitor and a non-zero current in the inductor), which would mess up the graphs for the first few seconds. If you do want to see what happens when you're connecting/disconnecting this - use the first switch right after the 3 phase rectifier.

published 2 years ago