function GFLIB_ControllerPIpFAsm in the example application AN5014SW

[kbk]

Hello,this question is about the function GFLIB_ControllerPIpFAsm in the example application AN5014SW. In the description of function GFLIB_ControllerPIpFAsm, the parameters : i16PropGainShift and i16IntegGainShift are defined as positive number, but in the file PMSM_appconfig.h ,they are defined as negative number. Can you explain it for me? Thank you.

[xiangjun_rong]

Hi,

Regarding your question, in general, proportional and integer shift  parameter: i16IntegGainShift and i16PropGainShift should be positive,for example for proportional value,  the actual proportional value is f16PropGain_Ksc =Ksc*2**(–i16PropGainShift), Ksc is proportioinal gain, i16PropGainShift is the proportional shift. From the formula, the i16PropGainShift parameter is used to increase the valid bits of the actual parameter if the i16PropGainShift is a positive. But If the i16PropGainShift is a negative, it can represent the value greater than 1. For example, the Ksc=0.5, it is represented as 0x4000, if you want to represent the value as 2, you can set the i16PropGainShift as 2, 0.5<<2=0.5*4=2

In conclusion, the shift can be positive and negative, in general, it is positive.

Hope it can help you.

BR

XiangJun Rong

[kbk]

It's very helpful,thank you very much.

I have another question. Are there any document,paper,application or code about flux-weaken control of PMSM based on MC56F827xx ? Other devices is all right. I did not find any support about flux-weaken control from your website.

Thank you very much.

BR

kb

[xiangjun_rong]

Hi, Kb,

I do not think we have specific documentation which focuses on flux-weaking method, in general, it is okay to set the Isd as a negative value so that the motor can increase speed.

But I think you can refer to an1931.pdf, which has a short part about the flux-weaking, pls refer to section 3.3.4.2 Control in Field-Weakening Range.

I attach it here.

BR

XiangJun Rong