New EV Charger Design - Modular

After delving deeply into the EMW 12 kW DIY charger, I think it would be best to make a new design. My concept is to make modules, each of which can be used on 120 or 240 VAC single or three phase, or up to 300 VDC. The modules would be 1.2 kVA for 120 VAC, and 2.4 kVA for 240 VAC or 300 VDC. They will be capable of being connected in parallel to obtain higher power. I think these modules could be built for a parts cost of less than $150 each.

The IGBT I show here is an ultra-fast 35A 600V device that is designed for switching applications up to 100 kHz, so I think the inductor and capacitor size and cost may be greatly reduced. And this part is only about $1.50.

Here is a "first shot" at this design. It has been done using Mentor Graphics PADS 2004 and most of the parts are fully characterized with part numbers and approximate cost, as well as PCB decals so that a board can be made directly from the schematic. A BOM in Excel format can also be produced easily with a VBA script.



Here is a PDF which is a little easier to read:
http://enginuitysystems.com/files/EMW/EV_Charger_PCB.pdf

And the BOM (preliminary) showing total parts cost less than $150:
http://enginuitysystems.com/files/EMW/EV_Charger_PCB_BOM_20141108.ods

This version is not PFC and non-isolated. It also has only a single pushbutton for start/stop, does not have a BMS connection, and has no display. But it has a serial port which can be connected to a Bluetooth module for viewing and logging data, and for commands. I am using only a 14 pin PIC16F1825 but it will probably need a 28 pin processor to provide the additional I/O needed. I have an Arduino UNO and I will try to add the connections to match its pinouts. I might also see if I can adapt the EMW control board with its display and function keys.

I am putting together an order to Mouser for some of the parts I will need for this design, and I am also going to get an AVR Dragon which is a $53 emulator/debugger/programmer which is really the very minimum needed for development of any serious design with the Atmel series microcontrollers. I plan to use this for analyzing the EMW charger (when I get a complete unit or the boards and parts needed), and hopefully be able to provide recommended modifications to the hardware and firmware to improve the reliability and performance. I think it may require a complete new set of boards, but many of the expensive components may be able to be re-used.