Search found 329 matches

by marcos
Dec 24 2016 4:53pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Only added a few bolts to support the board and changed the connector for a 12pos header. board.png Here is a 3D view, its a bit troublesome to update, I won't publish it this way very often. https://skfb.ly/XZzD And trew it in the cad to see how the 3 phases look together with a brain board on top ...
by marcos
Dec 22 2016 10:23am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

I wont comment about fc/fm stuff until I find the book... In the meanwhile, I added phase voltage sensing phase sensing.png Schematic sheet is here https://eyrie.io/board/c5ac1a5f21ce4684914535b2669bd01a?active=schematic&sheet=6&x=6492197&y=4218298&w=14165749&h=7656809&flipped=false Next stop is the...
by marcos
Dec 20 2016 9:06pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

the nH here is small... so small in fact that you might be able to get equal nH if you change the width of the tracks to compensate... Trying this random calculator found online, I get 110nHy with a 1.6mm thick pcb with 2mm traces that is 11cm long. Using this 4 layer/thin laminate approach I get 5...
by marcos
Dec 20 2016 5:52pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

agreed the cost is not prohibitive, but don't go more than 4 layers. Yes, 6 layer boards turned out to be a bit finnicky in my experience, had some non negligible warping due to power planes design. the nH here is small... so small in fact that you might be able to get equal nH if you change the wi...
by marcos
Dec 20 2016 10:02am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Changed the layout a bit for more symmetry and better placement of the caps next to transistors. driver layout.png Also, I decided to go 4 layers in order to have better current loops management, and to lower the gate tracks impedance. Its not that expensive when you factor in how many layout hours ...
by marcos
Dec 19 2016 4:29pm
Forum: Motor Technology
Topic: Hi power inverter for Nissan leaf motor. Dyno's 302.3hp p15
Replies: 577
Views: 104266

Re: Hi power high voltage inverter build for nissan leaf mot

Arlo1 wrote:Working on some gauges as well. :)
Nice dashboard! Is that a rpi?
by marcos
Dec 19 2016 1:55pm
Forum: Motor Technology
Topic: Hi power inverter for Nissan leaf motor. Dyno's 302.3hp p15
Replies: 577
Views: 104266

Re: Hi power high voltage inverter build for nissan leaf mot

8mm is a lot. The gate driver it self its only 7.5mm from the input to output side and it has a "• Safety approvals: UL approval, 5000 VRMS for 1 minute, CSA approval, IEC/EN/DIN-EN 60747-5-5 approval VIORM = 1414 VPEAK" So I wish you luck with 8mm. The trace you measured there is on the top and th...
by marcos
Dec 19 2016 7:50am
Forum: Motor Technology
Topic: Hi power inverter for Nissan leaf motor. Dyno's 302.3hp p15
Replies: 577
Views: 104266

Re: Hi power high voltage inverter build for nissan leaf mot

Hi Arlo, one thing I saw in your gate drivers (leaf and gamechanger) is that you should have larger cleareances between the traction pack side and the controller side. I see 1.6 and 2mm as the shortest path in the leaf. leaf cleareance.png For safety concerns, medical devices for example must have 5...
by marcos
Dec 17 2016 9:08am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

D.G. Homes, author of the book “Pulse Width Modulation for Power Converters: Principles and Practice” writes: The popular misconception that it is a triplen Yay! Thanks for looking it up HH, I'll give it a try. Today I figured out its a ton easier to integrate a variable duty pwm with RC than to co...
by marcos
Dec 16 2016 7:37pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

I've been thinking about adding a way to control the overshoot, by changing the negative gate control voltage, which originally was fixed at -8V. I saw this mechanism in a tesla patent, and seemed like a fairly doable way to get control over the overshoot and switching losses. So at low phase curren...
by marcos
Dec 14 2016 7:54am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

A couple of notes that HH pointed me to: I don't see snubber caps on your first page. i would like to ssee them direclty across your phase leg. don't show it with your DC link caps, put the 1uF snubber cap right across teh IGBT leg in the schematic. Placing like this in the schematic is like a remin...
by marcos
Dec 13 2016 3:38pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

What material are you using as a dielectric between the pos and neg bus and how thick will it be? I'd like to use 0.8mm bare FR4 without copper. FR4 has 20kV/mm, so it would provide adequate insulation. With a sheet like that I can drill it to align tightly the igbt, film caps and copper layers, so...
by marcos
Dec 13 2016 10:02am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

A while back when working on a water cooling system for TO 247 FETs I was looking at a 1/4 inch to 3/8 inch thick by 1 inch or so wide trip of aluminum furnace brazed to a 1/4 inch or 3/8 inch water/antifreeze tube tube. I like to add one drop of surfactant to the coolant (think Dawn dishsoap). Jus...
by marcos
Dec 13 2016 9:41am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

I have to calculate an approximate gate resistor value, and check the gate resistors power rating is okay.. gate resistor, keep in mind that its value has profound affect on performance of switch and so you don't really want it to change value due to self heating. also, gate resistors are netorious...
by marcos
Dec 13 2016 8:57am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

What PWM frequency are you planning on using, Marcos? 20khz at most. I'll probably use lower than 10khz you mean 21kHz. keep the switching frequency as a value evenly divisible by 3 and this will magic out some harmonics That short sentence got me into a lot of reading, and I still don't understand...
by marcos
Dec 10 2016 10:43am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Oh, okay okay, I'll keep that in mind. Battery pack is not laid out yet.
by marcos
Dec 10 2016 12:20am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

You want to stay away from the resonance frequency of the battery - controller(power input caps) parasitic inductance with the controller's power input caps. Thanks Njay, good to know. If cree's app note is right about the caps layout these half bridges should have <4nH and ~120uF, the resonance fr...
by marcos
Dec 09 2016 2:33pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Njay wrote:What PWM frequency are you planning on using, Marcos?
20khz at most. I'll probably use lower than 10khz
by marcos
Nov 30 2016 7:33pm
Forum: Motor Technology
Topic: power stage using SMD and IMS
Replies: 10
Views: 2084

Re: power stage using SMD and IMS

If you can point me to the gerber files of that application note I can get it quoted, I guess aluminum substrate pcb are on the expensive side.
by marcos
Nov 29 2016 1:30pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Thanks, thanks. The suggestion of an extra >100uF cap in the input is a good one, I'll check how to make room for it. I have one G-S cap placed for all transistors at the gate driver circuit: https://eyrie.io/board?active=schematic&id=c5ac1a5f21ce4684914535b2669bd01a&sheet=1&x=7753912&y=2936624&w=51...
by marcos
Nov 29 2016 9:18am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

I'd forgo that cap arrangement and use a single large DC link polypropylene cap right on the input for each phase. I used 600uF Cornell Dublier caps in my parallel research setups because the plan is to go > 1kA on low inductance motors. They can handle 100A RMS ripple current each and there are 3 ...
by marcos
Nov 26 2016 11:43am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

Its down to 13pF, and it looks less harmful now. coupling.png Yellow would represent the phase coper sheet, green the pcb bottom gnd plane. They only overlap below the igbt driver ICs. Its a 12mm x 14mm area on each side, 1mm separated from the copper sheet. That would be (12mm*14mm*2)*(4.7*8.854e-1...
by marcos
Nov 26 2016 10:25am
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

One thing to note in this general assembly, is that the PCB is on top of a large copper sheet (PHASE) that swings wildly. These 2 parallel copper planes make a capacitor that couples PHASE with the controller GND. planes.png This copper plate capacitor is 112pF between phase and gnd. Honestly I don'...
by marcos
Nov 24 2016 5:03pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

A simpler, maybe too simple approach would be this nand.png It asserts a FAULT when a wiring or firmware failure makes both inputs high, which otherwise would trigger a kAmp shoot through that would have to be dealt with the desat protection. Asserting the FAULT disables both IGBT drivers, and since...
by marcos
Nov 24 2016 12:02pm
Forum: Motor Technology
Topic: OSHW TO247 IGBT watercooled laminated half-bridge
Replies: 144
Views: 23900

Re: OSHW TO247 IGBT watercooled laminated half-bridge

I want to put some safety built in regarding accidental shoot through in case both pwm inputs are high due to noise... or bugs. Some approaches I see: * differential signaling from the controller * logic to avoid shoot throughs Differential signals like RS422 or LVDS could make the transmission more...