ZHCSDA7G July 2014 – February 2018 DRV10983
For any given motor, the integrated value of BEMF during half of an electrical cycle is constant. It is determined by BEMF constant (Kt) (see Figure 32). It is true regardless of whether the motor is running fast or slow. This constant value is continuously monitored by calculation and used as criteria to determine the motor lock condition. It is referred to as Ktc.
Based on the Kt value programmed, create a range from Kt_low to Kt_high, if the Ktc goes beyond the range for a certain period of time, tLCK_ETR, lock is detected. Kt_low and Kt_high are determined by KtLckThr[1:0] (see Figure 33).