Current Sensing with
1 января 2018
The TIDA-00778 reference design demonstrates fast and accurate current sensing for a three-phase motor driven with sensorless field-oriented control (FOC). Drives with lower audible noise require faster andaccurate current sensing. The most common low-cost current-sensing methods use a single shunt on the DC bus return path or two to three shunts in the inverter legs. The major challenge in motor control is to enable accurate current sensing even with the lowest active vector duration. TIDA-00778 demonstrates sub-microsecond settling and accurate current sensing in such scenarios. The referencedesign is applicable to major appliances,especially in compressor motors, and the inverter power stage can work up to 2 kW.
Fast and accurate current sensing for sensorless FOC with single-, dual-, and triple-shunt topologies to minimize torque ripple and audible noise in motor drives Single-shunt current sensing with minimum settling time and gate driver with lowest propagation delay enable active voltage vector duration < 1 μs Single-shunt DC bus current sensing with < 0.15% calibrated accuracy Dual- and triple-shunt current sensing with < 1.5-μs settling time and < 0.04% calibrated accuracy enabling accurate current sensing at extreme duty cycles Overcurrent detection with response time < 1.5 μs Input voltage 270-V to 390-V DC (rectified from 195-V to 265-V AC)