Frequency converter pre-charging resistor protection method

• Main Authors: OU QIBIN, HUANG KAIDONG
• Format: Patent
• Language: Chinese; English
• Published: 27.09.2022
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION

According to the frequency converter pre-charging resistor protection method disclosed by the invention, when the frequency converter is normally powered on, a coil of a second alternating current contactor (CTT2) is powered on, so that a main contact of the second alternating current contactor (CTT2) is closed, two pre-charging resistors (RFS2 and RFS3) charge an electrolytic capacitor on a bus through a CNV three-phase bridge rectifier circuit of an elevator frequency converter, after charging is completed, a first alternating current contactor (CTT3) is closed, and the first alternating current contactor (CTT3) is closed; the elevator operates normally; when the IGBT output is short-circuited, the elevator frequency converter detects through a sensor of the elevator frequency converter, performs logic judgment processing through a CPU in the elevator frequency converter, and switches the second alternating current contactor (CTT2) and the first alternating current contactor (CTT3), so that the power supply