iclim Posted February 25, 2014 Share Posted February 25, 2014 Hello, I was hoping you could shed some light on an issue that we have encountered. Upon performing manual current loop tuning, when the current has reached steady state I am noticing cyclic dips in the current (which the integrator responds to). I have attached a picture We are using an ACC-5E3 card with Geo MACRO Drives I have checked all of the commutation and direct PWM setting along with the pointers to the Geo MACRO registers. Do you have any suggestions? Link to comment Share on other sites More sharing options...
iclim Posted February 26, 2014 Author Share Posted February 26, 2014 I will also add that we tested two MACRO drives and the issue exists on both amplifiers. Link to comment Share on other sites More sharing options...
Omron Forums Support Posted February 26, 2014 Share Posted February 26, 2014 What is the inductance of your motor? Do you have a ferrite core on the motor leads? That might help. What are your current loop gains (Motor[x].IiGain, Motor[x].IpbGain, Motor[x].IpfGain)? What is the value of Sys.PhaseCycleExt? What are your clock settings on the Power PMAC and on the Slave (Geo MACRO)? Link to comment Share on other sites More sharing options...
iclim Posted February 26, 2014 Author Share Posted February 26, 2014 What is the inductance of your motor? Do you have a ferrite core on the motor leads? That might help. Ph-Ph = 18.5mH, exact same setup used in production and same issue does not exist What are your current loop gains (Motor[x].IiGain, Motor[x].IpbGain, Motor[x].IpfGain)? Motor[x].IiGain = 0.152 Motor[x].IpbGain = 0 Motor[x].IpfGain = 2.3 What is the value of Sys.PhaseCycleExt? It is set to 1 What are your clock settings on the Power PMAC and on the Slave (Geo MACRO)? Standard settings Gate3[0].PhaseFreq=9035.69161891937256 Gate3[0].ServoClockDiv=3 MACRO MI992 == 3275 (18.004khz) MACRO MI997 (Phase Clock Freq Control) = 0 We are checking our power supplies to the unit later on. Link to comment Share on other sites More sharing options...
iclim Posted February 26, 2014 Author Share Posted February 26, 2014 3 Phase power supplies were checked and appear to be fine. I performed the current tuning test with different magnitudes and the problem exists at all current targets. Link to comment Share on other sites More sharing options...
steve.milici Posted February 26, 2014 Share Posted February 26, 2014 This is probably not that bad maybe even over tuned. Reduce the current loop gains for a bandwidth around 250-350Hz and this should be OK. You may also have some ADC offset. Check out the process "Current Loop Offset Compensation Auto-Detection" in the Power PMAC User's Manual, see page 169. Link to comment Share on other sites More sharing options...
iclim Posted February 27, 2014 Author Share Posted February 27, 2014 Hello Steve, I have a few concerns: 1. I have set the ADC offsets already. 2. My main concern is that if you physically hold the output shaft of the motor, when it is holding a constant position target you can feel the vibrations in the motor shaft, which in a high precision position application is not be acceptable 3. This issue is not present on our other PMAC which uses the same setup. Thank you Link to comment Share on other sites More sharing options...
Omron Forums Support Posted February 27, 2014 Share Posted February 27, 2014 Hi, Please try setting the clocks identically on both your Power PMAC and the Geo MACRO Drive. You will need to increase the phase clock on the master to 18 kHz. Link to comment Share on other sites More sharing options...
iclim Posted February 27, 2014 Author Share Posted February 27, 2014 Charles, You were correct. We set the Gate3[0].PhaseFreq to 18kHz and here is the result. Thank you for the help Link to comment Share on other sites More sharing options...
iclim Posted September 20, 2014 Author Share Posted September 20, 2014 Hello, So I have encountered another current tuning issue on the same development setup and I have no idea why this started. For some reason my PPMAC reset to default values and now the current control for my motors is doing the following. Has anyone ever encountered this I have checked all the previous setting and both GEO MACRO and PPMAC have the same PhaseFrequency Link to comment Share on other sites More sharing options...
iclim Posted September 20, 2014 Author Share Posted September 20, 2014 Also I have two MACRO stations on the ring and both have the same behavior. I am assuming there is some PPMAC variable that has not been set correctly, but I cannot determine what could be causing this Link to comment Share on other sites More sharing options...
iclim Posted September 22, 2014 Author Share Posted September 22, 2014 Issue resolved, issue was caused by MacroMode configuration issue Link to comment Share on other sites More sharing options...
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