Gatekill motor fault on CTE620N3 and M1-101TF

Announcements

From sunburn to sun earn – we’ve got the power! Watch our #poweringgreen videos now.

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
Airtech
Level 1
Level 1
5 questions asked 10 sign-ins 5 replies posted

Hello, trying to drive an inverter refrigeration compressor, runs perfectly at low speeds (1200 to 2000rpm) but got gatekill motor fault when speed is increased above 2000rpm.

During configuration with MCE Wizard I got warning about Overcurrent Trip Level For Internal Gatekill Comparator, reducing the value doesn't takes out the warning message.

I don't know what to adjust to have the motor running at 4500rpm (or at least 4000) without faults.

Thanks in advance for help.

Best regards.

0 Likes
1 Solution
psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @Airtech ,

  1. If the motor's stator terminals are available, then it is possible to measure the motor parameters. Kindly refer to the document on How to measure motor parameters to get the measurements. 

  2. To get the precise and accurate measured value of the back emf by following the procedure given in the above document and also by the procedure in the MCE Wizard, following the below 2 ways might be helpful.
    ~ Rotate the motor shaft without supplying the motor for one full rotation trying to maintain it at a uniform speed, and the number of peaks is the number of poles, calculate the back emf constant value for a few cycles which are similar.
    ~ Rotate the rotor shaft using some prime mover at a known uniform speed, and calculate the back emf constant value from the voltage at the stator terminals. 

  3. Request you to capture the speed data (steady state speed, steady state error, etc) at speeds where the motor works perfectly fine as well as the speeds where  the motor doesn't rotate as expected. 

  4. Refer to section 4.2, 4.3, 4.4 of the iMOTION™ Software Reference Manual while debugging. 

  5. I can see that the DC Bus under voltage level is 120V. Any specific reason for this ? As the motor is reportedly working fine for speeds till 2000 rpm, please monitor the DC Bus voltage and currents to the motor at speeds above 2000 rpm and till the max speed of 4000rpm. Request to check and correlate with overmodulation both enabled and disabled. 

Hope these steps might be of help. 

 

Best Regards,
Sai

View solution in original post

0 Likes
9 Replies
psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @Airtech , 

    Thanks for reaching out to us !

    Can you please share the MCE Wizard configuration (.mc2) file and the motor datasheet as well. You can upload them here as a compressed folder (.zip, etc). Looking at the various parameter settings and values, we can get towards the root cause. 

Best Regards,
Sai
lock attach
Attachments are accessible only for community members.
Airtech
Level 1
Level 1
5 questions asked 10 sign-ins 5 replies posted

Thanks for your reply,

In attachment you will find the .mc2 file and a photo of the compressor nameplate, unfortunately we can't find a datasheet about this compressor.

So some parameters might be wrong, I'm sure about the pole numbers, stator resistance, Lq & Ld inductance but not sure about the back EMF constant (calculated from the formula with measurements done at 2000rpm).

Best Regards.

Léo

 

0 Likes

Hi @Airtech ,

You could refer to the below document to measure the motor parameters. In general the gatekill fault you mentioned is related to inaccurate motor parameter settings. 

https://www.infineon.com/dgdl/Infineon-How-to-Measure-Motor-Parameters-ApplicationPresentation-v01_0...

Could you also send us the schematic of the current sensing circuit to see if that has any issues?

Regards,

Ram

Airtech
Level 1
Level 1
5 questions asked 10 sign-ins 5 replies posted

Hi Ram, unfortunately I can't do all tests from the document you provided since the motor is an hermetically sealed refrigeration compressor.

Here's the schematic of the CTE620N3 board, haven't changed anything on the board.

cte620necurrentsensing.png

0 Likes
psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @Airtech , 

   1. Can you please reconfirm the calculation/measurement of back emf. It is a high value for the given speed range in the motoring mode, especially above 2000rpm.

   2. What is the DC Bus Voltage being supplied ?

Meanwhile, we are back calculating a few things from the other parameters as well. 

Thanks,
Sai

Best Regards,
Sai
0 Likes
Airtech
Level 1
Level 1
5 questions asked 10 sign-ins 5 replies posted

Hello Sai,

the back emf is calculated by the formula from MCE Wizard software and measurements done on the motor.
Tried other methods but that was either impossible to calculate (number of windings turns needed) or gave very different results (such as -533V).

The DC bus voltage is 340V, supplied from mains (240V/50Hz).

Meanwhile I was able to run the motor at 2600rpm for a few minutes, then is stopped in gatekill fault when going to 2700rpm.

Also tested other values of back emf (70V/krpm and 90V/krpm) but that ended in gatekill fault a few seconds after starting.

Thanks for your help.

Léo

 

 
 

 

 

0 Likes
psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello @Airtech ,

  1. If the motor's stator terminals are available, then it is possible to measure the motor parameters. Kindly refer to the document on How to measure motor parameters to get the measurements. 

  2. To get the precise and accurate measured value of the back emf by following the procedure given in the above document and also by the procedure in the MCE Wizard, following the below 2 ways might be helpful.
    ~ Rotate the motor shaft without supplying the motor for one full rotation trying to maintain it at a uniform speed, and the number of peaks is the number of poles, calculate the back emf constant value for a few cycles which are similar.
    ~ Rotate the rotor shaft using some prime mover at a known uniform speed, and calculate the back emf constant value from the voltage at the stator terminals. 

  3. Request you to capture the speed data (steady state speed, steady state error, etc) at speeds where the motor works perfectly fine as well as the speeds where  the motor doesn't rotate as expected. 

  4. Refer to section 4.2, 4.3, 4.4 of the iMOTION™ Software Reference Manual while debugging. 

  5. I can see that the DC Bus under voltage level is 120V. Any specific reason for this ? As the motor is reportedly working fine for speeds till 2000 rpm, please monitor the DC Bus voltage and currents to the motor at speeds above 2000 rpm and till the max speed of 4000rpm. Request to check and correlate with overmodulation both enabled and disabled. 

Hope these steps might be of help. 

 

Best Regards,
Sai
0 Likes
lock attach
Attachments are accessible only for community members.
Airtech
Level 1
Level 1
5 questions asked 10 sign-ins 5 replies posted

Hi, guys,

dur to the project modification we had to change the compressor and start the configuration over. We have the "Gatekill" error again, and the motor simply wouldn't start.

Could you please advise where it could come from and how to resolve it? 

Please note that we can't measure the motor parameters as we are dealing with a hermetically sealed refrigeration compressor.

0 Likes
psb
Moderator
Moderator
Moderator
250 sign-ins 25 solutions authored 100 replies posted

Hello  @Airtech ,

  Please follow the steps as mentioned in the above solution to measure the motor parameters and also configure the system using both the eval boards of Infineon. 

Best Regards,
Sai
0 Likes