SLAU927B June 2024 – November 2024 MSPM0G3507
Follow these steps if Slow first cycle is chosen as the startup method:
Step 1: Select Slow first cycle in the Motor startup option [MTR_STARTUP] in "Control Configuration – Motor Startup Stationary" tab in the GUI.
Step 2: Select align or slow first cycle current reference [ALIGN_OR_SLOW_CURRENT_ILIMIT]. Lower current reference may lose synchronization of motor. Higher current may lead to sustained oscillations for high inertia motors, or sudden jerky motion for low inertia motors. It is recommended to start with 50% of the rated current of the motor. In applications where the startup torque is high, the motor might lose synchronization. In such applications, increase the current reference. In applications where sustained oscillations or sudden jerks are observed, decrease the current reference.
Step 3: Select align or slow first cycle current ramp rate [ALIGN_SLOW_RAMP_RATE]. Current reference is ramped to avoid reverse rotation of the motor. Lower current ramp rate may lose synchronization of motor. A higher current ramp rate may lead to sustained oscillations for high inertia motors, or sudden jerking motion for low inertia motors. Start with setting the ramp time to 0.5 seconds to ramp to rated current of the motor. In applications where the startup torque is high, the motor can lose synchronization. In such applications, increase the current ramp rate. In applications where sustained oscillations or sudden jerks are observed, decrease the current ramp rate.
Step 4: Select the frequency of the first cycle [SLOW_FIRST_CYC_FREQ]. Lower frequency can give a jerky motion at startup. Higher frequency might not be able to synchronize the motor. Start with 20% of the maximum speed of the motor. In applications where the startup torque is high, the motor might lose synchronization. In such applications, decrease the frequency. In applications where jerky motions are observed, increase the frequency.