Briefly describe the stall prevention function of the frequency converter.

The stall prevention function of the frequency converter includes two aspects:
1. During acceleration: (1) If the acceleration time is set too short, it is easy to trip due to overcurrent. (2) If the acceleration time is too long, it will affect the machine's operating efficiency. Moreover, the operating conditions of the production machine are also constantly changing, which makes it difficult for users to set the "acceleration time" quickly and accurately. When an overcurrent occurs in the frequency converter during acceleration, it is not necessary to trip, but to start the "anti-trip" program (also called the self-processing program). The specific method is: if the current exceeds the preset upper limit value (i.e., the maximum allowable value of the acceleration current) during acceleration, the output frequency of the frequency converter will no longer increase, and acceleration will be temporarily suspended until the current drops below the upper limit value before acceleration continues.
2. During deceleration: For loads with high inertia, if the deceleration time is preset too short, the DC circuit may experience overvoltage due to the rapid release of the drive system's function. If the DC voltage exceeds the upper limit (i.e., the maximum allowable DC voltage) during deceleration, the inverter's output frequency will stop decreasing, deceleration will be temporarily suspended, and deceleration will resume only after the DC voltage drops below the set value. This function is often referred to as the anti-stall function.