Motor Jerks at start and multiple Speed Feedback faults

[STuser2]

I have multiple issues while driving the vehicle with the MCSDK software running. It is custom hardware MCSDK6.4.0

Hall sensor based.

1. Every time i start the vehicle at the beginning it jerks and then picks up, the behavior is not predictable, but jerking is always there some times more, less and hall fault etc. Now i have tested again on the bench and captured the waveform of the phase currents

The first few steps before the sinusoidal phase currents is problematic, so if i count i get 3 jerks before the motor started running. Can i eliminate this? It always happens when i start. Does it have anything to do with hall placement angle. I have not run the Motor pilot as i don't have the setup for that. I can perform multiple iterations of trial and error for the placement angle if the above angle is a problem at present it is 30. And my forward movement and reverse does not have the same placement angle may be due to the motor design.

Next major problem is intermittent speed feedback fault i can't predict when it happens this mainly occurs when i am starting the vehicle and also intermittently. On the bench i have tried to produce the issue

Measured angle started deviating from the super angle and fault happens.

Both the above are the same scenario 0x20 fault

All the start and stop scenarios all in between i find jerks. 

Starting jerk before starting. 

I have taken several failure graphs, if you can suggest me the correct direction i can look into. My only question the behavior shall be predictable but it is not.

[STuser2]

I wanted to know if i follow exactly the method proposed in the MCSDK documentation and get the HALL_PHASE_SHIFT.

will it be different from the value i get by running the motor profiler?

[STuser2]

It is mostly related to Hall noise trying to improve the hardware filtering.

[GMA]

Hello @STuser2,

Could you plot the STOPLL_EL_ANGLE and HALL_EL_ANGLE using Sto-Pll as the main speed sensor and Hall as the auxiliary speed sensor? The goal is to check if both angles are aligned during the startup phase.

[STuser2]

At present i am using the Hall sensor as the main sensor and not using the auxiliary sensor, for the purpose of debugging i need to do the setting as referred by you and confirm if both the angles are aligned at start up and then go back to the original configuration, is my understanding correct? 

[STuser2]

Initially i was running the MCSDK 6.2.0 now i migrated to 6.4.0, then i have done the configuration Sto-Pll as the main speed sensor and Hall as the auxiliary speed sensor as suggested, but the motor was not starting properly, so i  assumed that the motor parameters may be inaccurate, hence i started setting up the motor profiler and was successful in establishing the communication, i will run the profiler for my custom inverter and get the motor parameters and then feed into the sensor less algorithm. Could you please tell me if i am in correct direction? i need to solve the jerk issue at the start of the vehicle. 

[STuser2]

I ran the motor pilot program to determine the resistance, inductance, and other motor parameters but the motor runs upto 3 amps on the DC power supply (i have put limit on IqMax) and halts, motor runs for several iterations before it goes to speed feedback fault (28% completed). I don't know the exact procedure to run motor profiler, will it run to the maximum rpm and current or only % of the max current etc, I have not checked further on that but i am doing continuous tests on startup with different placement angles, can you please confirm the below is the best startup we can achieve, there are jerks happening at the beginning and if it is limitation using hall sensor. Regarding the placement angle i have captured the waveform as per the MCSDK documentation.

The placement angle is around 62 Degrees and i am using it the program, and the below are the startup waveforms i have captured at a particular load

How do i proceed further? 

[STuser2]

The actual scenario i have now captured in the lab the same scenario in vehicle

I have put a load of 80kg that is when the jerks start at the beginning of the vehicle, jerks are where the steps of the electrical angle are present, the rotor angle takes big time before it becomes sinusoidal. Could you please advise how do i solve this problem?

My observation is as the load is increased the jerks are increasing.

[STuser2]

I ran the profiler though it is not complete it stopped at 7% and giving the speed feedback fault, but motor was spinning for around 4 times in steps in that time i captured the waveforms, I am trying to run upto 100% but figuring out what values to be put for the constants, i don't know much theory of sensor less FOC.

Summary of the motor running

The above is in No load condition. There is slight offset i will further fine tune the hall placement angle. The main problem is coming under load condition, so can i run the profiler under load condition and capture the waveform and verify the difference?

[GMA]

Hello @STuser2,

From a feature perspective, the motor profiler is intended to be used with the motor alone.
Did you try using the torque mode (instead of speed mode) to command the maximum torque and verify if the startup is linear? Be aware that the motor will run at maximum speed in this case.

In speed mode, did you try tuning the speed regulator PID parameters to make it more reactive by increasing the proportional parameter?