The inverter for air compressors has undergone another round of innovation and upgrading amidst today's technological advancements, leading to changes in the screw air compressor system. Frequency control is increasingly widely applied in screw air compressors, with permanent magnet variable frequency screw air compressors and two-stage compression permanent magnet variable frequency air compressors being popular products in the current market.

Regarding air compressor inverters, we all know that their primary function is energy conservation, achieved by adjusting the motor's speed. However, air compressor inverters also offer a series of protective functions:

The inverter has a voltage detection function at its output and can automatically adjust the output voltage to prevent the motor from experiencing overvoltage. Even if the output voltage adjustment fails and the output voltage exceeds 110% of the normal voltage, the inverter will protect the motor by shutting down.

When the motor's voltage drops below 90% of the normal voltage, the inverter will shut down to protect the motor.

When the motor's current exceeds 150% of the rated value for 3 seconds or 200% of the rated current for 10 microseconds, the inverter will protect the motor by shutting down.

The inverter monitors the output voltage and, when a phase loss occurs, it will trigger an alarm. After a certain period, the inverter will shut down to protect the motor.

The inverter ensures that the motor can only rotate in one direction. The rotation direction cannot be set unless the user changes the phase sequence of the motor's A, B, and C connections, making reverse rotation impossible otherwise.

The inverter monitors the motor current and, when the current exceeds 120% of the rated current for 1 minute, it will shut down to protect the motor.

The inverter is equipped with a dedicated grounding protection circuit, typically consisting of a grounding protection transformer and a relay. When one or two phases are grounded, the inverter will trigger an alarm. If required by the user, we can also design it to shut down immediately upon grounding.

After a short circuit occurs at the inverter's output, overcurrent will inevitably result. Within 10 microseconds, the inverter will shut down to protect the motor.

The inverter has maximum and minimum frequency limit functions, ensuring that the output frequency remains within specified ranges, thereby achieving overfrequency protection.

Stall protection is generally aimed at synchronous motors. For asynchronous motors, stalling during acceleration will inevitably manifest as overcurrent, and the inverter achieves this protection function through overcurrent and overload protection. Stalling during deceleration can be prevented by setting a safe deceleration time during the debugging process.