Unable to activate over current protection on ST Workbench (6.1.2) with a custom board

IrianJ · ‎2023-12-04

Hello,

I've made a custom card and I'm stuck on two features in particular:
- over-current protection
- Current sensing

They don't show up in the ST Workbench Pannel.

[VERSION]: 6.1.2
[TOOL]: MC WB

[DETAILS]:

here is an extract of my custom board (current Sensing):

 {
                  "name": "CurrentSensing",
                  "type": "CurrentSensing",
                  "tRise": 59, 
                  "hwVariants": [
                      {
                          "type": "SingleShunt_AmplifiedCurrents_noOffset",
                          "shuntResistor":0.0005,
                          "opAmpGain":20,
                          "amplifyingNetworkImax":330,
                          "amplifyingNetworkVm":3.3,
                          "amplifyingNetworkPrating":10, 
                          "signals": {
                              "CURRENT_AMPL": [
                                {
                                  "name": "PA3",
                                  "help": "",
                                  "cost": 0
                                }
                              ]
                            }
                      }
                  ]
              }

And for overcurrent protection :

{
                "name":"OverCurrentProtection",
                "type":"OverCurrentProtection",
                "hwVariants": [
                  {
                    "type":"SingleInput_RawCurrents_Protection_IntRef",
                    "OCNetworkGain":20,
                    "OCNetworkOffset":0,
                    "OCComparatorThreshold":2,
                    "OCSignalPolarity": "Active high",
                    "signals": {
                      "CURRENT_INPUT_P":[
                        {
                          "name":"PA7",
                          "help":"",
                          "cost":0
                        }
                      ]
                    }
                  }
                ]
              }

Yet, on WB view, I got these :

I'm working on a custom Inverter with a STM32G431RTBx and all the other features show up well.

[EXPECTED BEHAVIOR]:be able to activate overcurrent protection and current sensing.

Thank for your help,

Irian

SRedd.5 · ‎2023-12-05

The B-G431B-ESC1 Kit based on STM32G431CB i used this, there are other boards with RB series i think.

The board B-G431B has current sensing

and over current protection. After generating the code you may need to make changes as per your requirements.

cedric H · ‎2023-12-05

Hello @IrianJ,

Do you want to use FOC algorithm or 6-steps ?

What is you targeted MCU? 6-steps algo is supported on a limited series compared to FOC.

Do you use a ST board you want to modify as a starting point ? if yes which one ?

SingleShunt_AmplifiedCurrents_noOffset is dedicated to 6-steps because the current sampled is always positive.

Regarding the OverCurrent protection, may I ask you what is your driver? Most of the time drivers have a Fault signal that is use in the MCSDK for the Driver Protection feature. Your Hardware Variant makes use of raw currents, it means non-amplified current ( connected directly from the shunt). I guess it is not your use case.

Regards

Cedric

IrianJ · ‎2023-12-07

Hello @cedric H,

Thank you for your time and your reply.

Here's a bit more background on my use of the tool. I want to evaluate the software generated by ST Workbench on our own motor controllers and motors (which run today on our own software).

- I want to use 6-steps only. MCU used is a STM32G431RBT6 (which is compatible with FOC and 6-steps). I am not starting from a ST board but I'm using them as examples to build my controller's board description.

The driver used is DRV8350RSRGZR but we want the software to be as driver-independent as possible, as the driver may change in the near future and it already has two single-shunt (redundant) current measurements in place.

You are right ! We do not use raw current ! We have two amplified current input. I want to use one for current sensing, and the other for overcurrent potection with a internal comparator and internal generated reference (as we do in our proprietary software). The two currents inputs have the same amplification ratio. Maybe this is impossible with the workbench ?

Regards,

Irian