topic Re: current wave in CodeWarrior for MCU

current wave

guochunhua — Tue, 17 Jan 2017 02:21:54 GMT

Hi.

Excuse me, in codewarrior 10.7, the MCU is 56f84789 , the motor current measured by hall sensor is distorted near the rising edge,the figure is on the attachment. the dead time is 3us, perhaps the distorted wave is influenced by dead time, how can I configure the dead time rigister correctly? thanks a lot.

电流霍尔传感器测量的电机电流波形，在电流上升沿过零点附近产生畸变，有可能是死区时间影响，死区时间是3us，可能是死区时间寄存器配置不正确，请问如何正确配置死区时间寄存器？

Best regards.

Guo chunhua

Re: current wave

xiangjun_rong — Wed, 18 Jan 2017 03:12:46 GMT

Hi, ChunHua,

Do you use VVVF algorithms to control a ACIM? The VVVF alforithms has a drawback because of deadtime insertion.

Xiangjun Rong

Re: current wave

guochunhua — Wed, 18 Jan 2017 10:38:41 GMT

Dear Xiangjun.

I use VVVF algotithms to control a PMSM, the motor current measured by hall sensor is distorted near the rising edge, if the configuration of deadtime register is wrong ,why the falling edge of current wave is not distorted? how can I do? thanks a lot.

用VVVF算法控制pmsm，电流上升沿过零点附近产生畸变，如何克服这个缺陷？如果是死区寄存器设置有问题的话，为什么只有上升沿有畸变，而下降沿没有畸变？

Best regards.

Guo chunhua

Re: current wave

xiangjun_rong — Thu, 19 Jan 2017 04:12:03 GMT

Hi, ChunHua,

The cause of the distortion is that the Sine table is accurate in top waveform, but inaccurate in bottom waveform because of deadtime insertion. But the deadtime is only dependent on the power device you are using to avoid both power device are on, the deadtime can not be changed but can be compensated for the distortion.

Pls refer to an1728.pdf.

XiangJun Rong

Re: current wave

guochunhua — Wed, 15 Feb 2017 04:07:51 GMT

Hi xianjun.rong

Thank you for your help. the attachment is my current wave and my deadtime compensation program，the current wave is distorted, what is wrong with my deadtime compensation program? thanks a lot.

Best regards.

Chunhua Guo