Reactive Current Braking is one of the 3 methods for controlling the induced EMF voltage generated on deceleration in the motor's coils as they rotate within the magnetic field. Reactive current braking uses the motor cable's resistance as well as the motor's winding resistance to dissipate this energy. By knowing the cross-sectional diameter of the motor cable conductors, the length of the cable, and the winding resistance, we can calculate the maximum energy that can be dissipated using Reactive Current Braking. When using the CMMT-ST-MP with a battery powered AGVs, forklifts and AMRs, we may be interested energy savings rather than turning this induced EMF voltage in the wasted heat. The voltage level in the battery type and the battery maintenance system (I.e. BMS) will determine the settings of the Reactive Current Braking function in the Festo's CMMT-ST-MP. In general, we will want to disable the Reactive Current Braking function to allow for Energy Savings in the CMMT-ST-MP when connected to a Battery.
Software: Festo Automation Suite - version: 2.10.1.1
Software:CMMT-ST Plugin - version: 2.9.2.0
Software:CMMT-ST Firmware - version: 36.10.4.9494
In this use case, a customer was using the CMMT-ST-MP on a AGV with a LiFePO4 Lithium battery. The measured nominal voltage of the battery was 56.5 VDC @ full charge and used as the load supply voltage to the CMMT-ST-MP. Looking at the battery's charging specification showed that the maximum charge voltage is 57 VDC.
This post is provided solely for the purpose of offering setup assistance and general guidance. It is important to note that the ultimate responsibility for ensuring the overall safety and proper functionality of the machine lies with the System Integrator / End User. It is crucial to exercise caution, adhere to proper safety protocols, and consult relevant experts or professionals when necessary.
Although Festo employees will be contributing to this blog, please note this is not the official Festo support channel. For more timely technical support please reach out to your regional Festo support channel and/or consult user manuals and relevant documentation.