A 3kW reference design - Coming soon
Hey guys! First time righting a post in this community. I'm bulding a 3kW PFC with the Frenetic tools to design the power inductor. Take a look on what's coming.
Short specs list:
This is a 3kW classic boost PFC. It is powered from mains input (230VAC +-15%) directly, outputting a nominal 390V@3000W. The design uses ICE3PCS03G as the controller IC and two Coolmos power mosfets (IPW60R099P6) in parallel to be able to handle the output power. The PFC can also work in boost follower configuration. There are also two 60x60mm fans with automated speed control to keep temperature rise under control.
Design process of a prototype:
Designing a new PFC, or in fact any other power topology, as engineers we’ve got one way to go about it. We have to build on prior knowledge gained from personal involvement in previous projects or by using the available reference designs that exist nowadays in the web. The major players in the power electronics field are Texas Instruments, Infineon, ST devices to name a few. One can find lots of reference designs out there, built by experienced engineers, to start designing his own system. The process is relatively easy when one learns all aspects of his selected topology, following the reference designs and app note equations, to calculate all system voltages, currents, component values etc. Everything is fine, right? Not so fast… Sooner rather than later, the aspiring engineer will begin to notice, that when it comes to the magnetics designs, there is practically no data available in most reference designs! What is usually the case, is the magnetics construction being assigned to another company. Designing a power inductor has lots of parameters to consider. The first thing an engineer asks is: “Can the coil sustain the current and is it going to be relatively cool under full load?”. That is a very good but complex question, as the following questions should be answered first. What’s the operating flux swing? Is the core near, or far from saturation under worst conditions? How is the inductance value dropping under DC current? Are the core losses acceptable? What about skin, proximity effect presenting an AC resistance on top of the classic DC wire resistance… Which winding topology should we use to minimize the winding losses? Answering all these questions takes lots of time and effort, and the new engineer will soon find himself in a position of spending far more time trying to configure magnetic design, rather than focusing on the rest of the system.
Using the frenetic tool, I managed to answer all of the above in a fraction of time. What I did basically is to input the PFC’s basic specs then select core materials for PFC usage. The rest of the calculations were made from the tools. So, I selected a couple of different cores and winding scenarios to verify different power dissipation levels (calculated from the tools) and ordered custom samples directly from the site.
What’s coming is an application note/performance report and the design files of the 3kW PFC shown here. Comparison of the Frenetic samples will be made in the report, as well as a video guide with all necessary steps taken to order the samples, mentioned.