openinverter forum

Does anyone know of a way to test the Hübner VCU control circuits to verify their functionality?

I get 16v from the Prius Gen2 inverter on MVU, MUU, MWU wires, but am not sure if the VCU is signaling. I have a meter that will read both duty cycle and Hz in the range needed, but am not enough of an EE to prove either is working or not.

I have tried connecting lamps to the VCU wires and +12v with no joy and placing them between the VCU and inverter with no joy, attempted to measure Hz (~7.6kHz) at varying VCU command outputs with no joy.

Ideas are most welcomed!

Maybe you can try this:
If you disconnect the VCU PWM outputs from the inverter (9:MUU, 10:MVU and 11:MWU) and then measure from each of the three signals to GND for voltage, duty cycle and frequency (Hz). The VCU should be running in manual mode with all done to give PWM output.
https://openinverter.org/wiki/Schematic ... structions
See section "Connecting the gate drivers"

I expect all 3 pins to be equal with a voltage of 1,65V; 50% duty cycle and a frequency matching the setting (4,4; 8,8 or 17,6kHz).
If this is true I belive the VCU works.

Reconnect the VCU PWM to the inverter. Apply a small voltage source (~12-24V) to the inverter DC input. Now run in manual mode as above and measure between phase output for one motor phase and DC input negative. No motor connected. Measure voltage, duty and frequency for all three phases. If everything is ok all three phases should be equal.

That is VERY helpful! I did not follow that instruction list, because I misbelieved that it applied to the built-it-yourself piece of kit and not to the "RTR" kits.

Thanks!

From the "Gate Driver" instructions: "Power up the inverter, which will now pull around 300mA @ 12V.", my Prius board only pulls 122mA, (that *may be* normal for these), gate driver results suggest they are not active, hence the lower than expected supply current.

2-4Hz, regardless of settings
28-33mV, regardless of settings
78-99%, regardless of settings

Looks like the VCU is dead, now I need to figure out what went wrong and not only how to fix it, but more importantly to prevent it in the future.

ULN2003A on the way, hope this will "fix" my problem.

While thesting the PWM outputs there where no errors inhibiting PWM? Over current, over voltage etc and you had a direction selected?
I agree that your current consumtion does sound reasonable as you do not have the gate drivers connected.

I don't understand what you are trying to fix with a ULN2003A?

I would try to measure the PWM signals directly at the STM32 outputs. I don't have a schematics for your particular board so I can't give any more details.
You could also try and reprogram the STM32. Just to see if that works or not. Also double check everything for things that could inhibit PWM output.

Inverter shows to be in "Manual Run" with no active errors and settings per the "connecting gate drivers" instructions.

It has been flashed to FOC, SIN, FOC and now SIN with no change in behavior. This all started when two things happened: 1) MG2 U shorted to MG2W resulting in melted 20ga wire insulation and 2) I changed to FOC from SIN.

I have not been able to verify correct output of the VCU ever, I simply do not know how other than what has been described in this thread. Although my first tests with SIN produced motor jiggle, that is no longer true.

I do not think a short on the MG2 output should be able to damage the VCU unless you are using the same power source for both VCU and DC-link?
The VCU should be flashed with "sine" to work in manual mode, as stated in the instructions.

When trying to get PWM-output can you see direction forward selected? No output when in neutral.
Are all supply voltages on the VCU correct?

I recreated the original setup, with one change, I connected the VCU to MG1 instead of MG2 and still have no output from the Inverter. SIN, Manual Run, opmode = Run, fslippnt & ampnom = 1 per the instructions.

I have 15v on the inverter phase control wires but they are not being pulled down by the VCU with any PWM. There is 100Hz nominal to the driver chip on the 3rd pin in from the board edge as well as 5.4v on the near corner and 14.4v on the far corner (on large pin side). So, it would appear the VCU is unable to produce gate driver PWM

I agree, there seem to be something wrong with the VCU.
At this point I have no further idea than to try and find the fault on the VCU.

ZooKeeper wrote: ↑Fri Jul 24, 2020 2:16 am So, it would appear the VCU is unable to produce gate driver PWM

If you add your location to your profile we may be able to help you. I know that several forum members in Ireland and the UK are actively working together

So I bought another inverter, not that I need a 4x4 vehicle or have another MGR to use with it, but for testing as it was cheaper than another VCU.

Same results, absolutely zero inverter output on MG1 or MG2 and the resolver circuits are not working, so I am pretty sure the VCU is damaged. Resolver wiring ohms out the same as before, I will take that as good news

I found the diagram for the board, but it calls out Q1, 2 & 3 as drivers, but I can only find Q1 & Q2 on the board.

At least I know to concentrate the testing on the driver chip and resolver circuits Now if I only knew what I was looking for

Q3 is an oscillator or something like that. It is located next to the STM32 Pin 1 location. Rectangular.

Well I'll be, thanks!

Unfortunately that does not match the diagram I found (attached), not even close. From the diagram, Q2, 3 & 4 should be the PWM control connected to the inverter MUU, MVU & MWU, but shown on different pins than the production board. Guessing Q5 is for CPWM?

The good thing is I am not over my head in this, but just about

I would start by checking that all supply voltages are ok on the VCU. The tricky part is to find points to measure them without schematics and layout.
There should a least be a 3,3V supply to the STM which will be present at the STM supply pin. To find this one you need to find the exact STM used on your board and then look in the datasheet.
There should also be some sort of supply for the resolver exciter circuit. And also you should be able to measure the AC voltage output by the resolver exciter circuit to check if it is live or not.

I have been over and over the board looking for abnormalities and finding none, I performed some voltage tests as suggested. However, the diagram I found for the V1.1 board was in the "Prius Gen2 adapter board" thread and does not match what I can find on the board.

Link: viewtopic.php?f=14&t=701&start=80

So I did the best I can with a DMM and aside from Red LEDs on my board, when the diagram seems to call for Green, the board itself seems intact. The only things I see wrong or odd are that there is no PWM from the STM32 pins 41, 42, 43 that I can see and from the diagram, MCU pins 19, 32, 48 & 64 are tied together, but the voltage readings suggest that is not (or no longer) the case.

The below are all DC, I did measure the exciter/resolver pins 1-5 @ VCU connector and measured only a few mv ac or dc

Inverter Header:
Pin / "Off" / "On"
1 = 1v65 / 1v65
2 = 1v65 / 1v65
3 = 1v65 / 1v65
4 = 1v65 / 1v65
5 = 14mv / 13.4mv
6 = 0v95 / 0v95
7 = 3.1mv / 1.4mv
8 = 300mv / 210
9 = 350mv / 251
10= 367mv / 312
11= 380mv / 374
12= 1.8mv / 388mv

IC2 Pins: Off / On:
01 = 3v3
07 = 3mv
18 = 3.5mv
19 = 2v5
22 = 7 / 8.8mv
23 = 8 / 5mv
31 = 7mv
32 = 0v67
47 = 4mv
48 = 2v4
54 = 14 / 18.5mv
60 = 2v1
63 = 5.8mv
64 = 3v3

"Power Supply" (UTC ??):
1 = 2v5
2 = 5v4
3 = 2v5
4 = 2.8mv
5 = 0v5
6 =
7 =
8 = 0v5

"Excitation" (MCP60021 ??):
1 = 1v8
2 = 1v6
3 = 1v6
4 =
5 = 5v4
6 = 1v8
7 = 1v5
8 = 1v7

If you can find IC8, which should be a 3-pin IC marked REG1117, measure DC-voltage on pin 3 to pin 1 and pin 2 to pin 1. This should be VCC and VCCIO.

If you have "encmode" set to "4, Resolver" you might not get any pmw output if the resolver exiter does not work. Try and set this to "0, single channel encoder" and test if you can get PMW output in manual mode.

To get an resolver exicter output you need "encmode" to be set to "4, Resolver".
To measure the resolver exciter voltage the multimeter needs to be in AC-voltage.

I don't see IC8 on my board. We are talking about Adapter Board for Gen 2 Inverter.
There is a Zip file - prius-gen2-v1.0.pdf on Johannes' Patreon account. Have you got access to that?

No, sorry I don't.
Look for pins marked VCC and similar. This is usually the 3,3V.
Anyhow, you have still communication with the STM, right? So then the 3,3V should be ok.
Probably a good idea to start trying to figure out why you have no resolver exciter output.

I have a v1.1 Huebner Gen2 Prius board, no IC8 here and yes I can communicate with it just fine, read and write, it just will not "work". I see that not only did I lose the resolver/encoder data, but also that of the iL1 & il2 sensors

Ok, is this board similar to Damiens PriusG2_V1? Schematis can be found here: https://github.com/damienmaguire/Prius- ... ematic.pdf.

If it is, can you measure the DC voltage at the current sensor inputs, TB3 pin 7 and 8? With the inverter connected and no current.

No, there are very significant differences. The JH version uses all the Prius sensors and controls, but I can check the iL1/2 input voltage from the inverter.

Edit: I can see current data once I re-read the instructions, "Manual Run" DOH! But it swings wildly +/- 2A on both il1 & il2 and I am feeding it 2.5A, so need more power to figure out which is which.

Ok, so you can see some current but still no resolver.

To get an resolver exicter output you need "encmode" to be set to "4, Resolver".
To measure the resolver exciter voltage the multimeter needs to be in AC-voltage. Also disconnect any loads i.e. only connect the multimeter to the exciter output.

As measured in ACV on the VCU, encmode = Resolver, Mode = Man_Run
Pin / Desc
1 = B/S3
2 = S1S4
3 = A/S1
4 = MRF
5 = MRFG

1 > 2 = 0.071
3 > 2 = 0.055
4>5 / 5>4 = 1.23

Ok, so it looks like you have some exciter output. 1.23V RMS.
What is the output 4>5 with the resolver connected?
Also, with the resolver connected, what is the 1>2 and 3>2 AC voltages. If everything is correct they should vary depending on the motors position. (motor should be stationary when measuring)