How to solve Error Code 8

Fault code:

【8】Bus overvoltage software protection

Reason:

Insufficient ADC sampling accuracy: Low analog-to-digital conversion bits or insufficient sampling frequency result in missed peak voltage sampling and delayed protection action.

Excessive digital filtering: Setting an excessively long sliding average window to eliminate noise, which smooths out the true overvoltage signal and misses the protection opportunity.

CPU processing load is too high: The main control chip (such as DSP, MCU) is simultaneously processing multiple tasks (such as vector control, communication protocol), causing the overvoltage detection task to be interrupted with a response time exceeding 10ms.

Unreasonable protection threshold and hysteresis setting: The threshold is too low, resulting in frequent protection during normal fluctuations; The hysteresis width is too small, and the protection is repeatedly triggered when the voltage oscillates near the threshold, causing system instability.

Defects in brake logic design: The brake starting voltage overlaps with the hardware protection threshold, resulting in dual protection conflicts;

solution:

Insufficient ADC sampling accuracy: Replace with high-resolution or external dedicated sampling chips, increase the sampling frequency to above 20kHz, use DMA to transfer data, and reduce CPU intervention.

Fault mutual inspection mechanism: The software regularly sends test signals to the hardware protection circuit to detect whether the hardware is responding. If there is no response for three consecutive times, the software redundancy protection is triggered; When hardware protection is triggered, an interrupt signal is sent to the software through GPIO, and the software records the fault and executes the shutdown process to avoid independent hardware actions causing system loss of control.

Note: Please do not dismantle the machine without permission, otherwise it will be out of the warranty of Ktech.