System and method providing reliable over current protection for power converter

• Main Authors: Kang, Xiaozhi, Fang, Lieyi, Huang, Xiaomin, Yang, Dongze, Lyu, Huawei, Lin, Yuan
• Format: Patent
• Language: English
• Published: 19.02.2019
• 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

System controller and method for protecting a power converter. The system controller includes a first controller terminal configured to output a drive signal to a switch to affect a first current flowing through a primary winding of a power converter. The power converter further includes a secondary winding coupled to the primary winding, and the drive signal is associated with one or more switching periods. Additionally, the system controller includes a second controller terminal configured to receive a sensing voltage from a sensing resistor. The sensing voltage represents a magnitude of the first current flowing through the primary winding of the power converter. The system controller is configured to process information associated with the sensing voltage and a reference voltage, and determine whether an average output current of the power converter is larger than a current threshold.