Elevator frequency converter fault detection method and system

Abstract

The invention relates to an elevator inverter fault detection method and system. Three-phase voltage of an inverter switch tube is studied, and three-phase current is correspondingly studied; thereby, while an elevator works, three-phase current of the inverter is detected, and whether 90%-100% of a rated current value exists in a three-phase current law is further judged; if yes, whether the inverter works normally is judged; if not, the three-phase current law is further judged, and whether a U phase, a V phase and a W phase of the inverter are normal is judged. Accordingly, whether elevator inverter current is normal can be judged timely, and the inverter can be prevented from being damaged due to abnormal elevator inverter current.

Description

technical field [0001] The invention relates to frequency converter detection technology, in particular to a simple and easy-to-implement elevator frequency converter fault detection method and system. Background technique [0002] In the elevator control system, VVVF full frequency conversion control is basically adopted at present, and the output of the frequency converter is directly connected to the three-phase terminal of the motor through the output contactor and the motor line. Once there is a problem in a certain link, the elevator will run abnormally. When the elevator is running normally, after detecting that the feedback contact signal of the main output contactor is valid, the system follows the double-loop control of the closed-loop vector speed loop and current loop. The disadvantage of this method is that once the main output contactor contact feedback signal has a problem, the main output contactor has not been really closed, when the inverter and the motor ...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that once there is a problem with the feedback signal of the main output contactor contactor, the main output contactor has not been really closed, and when the inverter and the motor have not been connected

However, the control system cannot detect the current. According to the double-loop regulation rule, the inverter will output a higher voltage at this time. After a period of time, after the main output contactor is connected and the motor is connected to the inverter, such a high voltage will be applied to At the motor end, if the inverter reports an overcurrent fault, if it is serious, it may cause damage to the inverter

Or when there is an abnormality in the current detection link, due to the closed-loop control, the system may explode

Images