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FW version: Stable

Battery limiter

info

The following variables are located in the /driver/limiter folder.

note
  • Current direction from the battery to the motor is considered as positive (motoring, battery is being discharged).
  • Current direction from the motor to the battery is considered as negative (generating, battery is being charged).
  • To disable a limiter, set its threshold values to zero.

Parameters​

Battery current limitation​

ibpos [A]​

Set limitation for battery current in the positive direction (discharging, from battery to motor). Use a positive value for this threshold in typical scenario.

ibneg [A]​

Same as ibpos but, for the negative current (charging, from motor to battery). Use a negative value for this threshold in typical scenario.

warning
  • Since the limiter response time is finite, it is not possible to prevent current to flow into the battery by setting ibneg to near zero. Always use a battery (or PSU) that can handle iref current in both directions momentarily.

ibgain [-]​

This parameter sets the dynamic response. Higher values lead to quicker response to the DC-side over-current (negative or positive) but may lead to oscillation and stability issues with this limiter. Lower values lead to smoother responses.

Hints
  • This limiter is an integral-type limiter and its limitation speed depends on the ibgain parameter.
  • Due to the reaction times, this limiter may not be used for preventing the BMS short circuit protection trigger. BMS short circuit protection threshold must be set greater than the ipeak parameter in the controller (assuming comparable reaction times).

Battery voltage limitation​

ubmin [V]​

Sets the minimum battery voltage limit. Typically, this is used to prevent the controller from emptying and/or destroying the battery.

ubmax [V]​

Same as ubmin but, for the maximum voltage. Typically, this is used to prevent the controller from overcharging and/or destroying the battery.

ubgain [-]​

This parameter sets dynamic response. Higher values mean quicker response to the voltage (negative or positive), but this may lead to oscillation. Lower values will lead to smoother responses.

Hints
  • This limiter is an integral-type limiter and its limitation speed depends on the ubgain parameter.
  • If your battery's internal resistance is higher, set the ubgain parameter to a higher value.

Power limitation​

ppos [W]​

This parameter will set maximum power taken from battery.

pneg [W]​

Same as ppos but for negative power (recuperation).

pgain [-]​

This parameter sets the dynamic response. Higher values mean quicker response to the voltage (negative or positive), but this may lead to oscillation in this limiter. Lower values will lead to smoother response.

Hints
  • This limiter is an integral-type limiter and its limitation speed depends on the pgain parameter
  • Dynamic of this parameter can be set by pgain
  • In some of the applications, some parameters may be set as "volatile", rendering them as not being user-settable and not saved to the FLASH memory. This is because they are altered by the user application. Example: ppos in the LYNX is set individually per each power_map.