Capacitor charging and discharging model-based motor relative case short circuit detection system and detection method thereof

• Main Authors: ZHU NANNAN, WANG JUN, LIN SHENG, WANG HANNING, DANG JIN, DONG JINBAO
• Format: Patent
• Language: Chinese; English
• Published: 20.05.2022
• Subjects: CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS; GENERATION; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

The invention relates to the technical field of motor driving and fault detection, in particular to a system and a method for detecting short circuit of a motor relative to a casing based on a capacitor charging and discharging model. The system further comprises a Y capacitor charging and discharging model operation module, a PWM wave sending module, a three-phase bridge driving module, a current sampling module and a fault detection and protection module. The method comprises the following specific detection steps: S51, constructing a Y capacitor charging and discharging model; s52, operating key parameters of the short-circuit model; s53, a PWM (pulse width modulation) initialization component; s54, PWM (Pulse Width Modulation) state machine control; s55, carrying out PWM key parameter operation; s56, a PWM wave sending module; s57, a three-phase bridge driving module; s58, a current sampling circuit; s59, a sigma-delta sampler and a demodulator; s510, judging whether a fault exists at present or not; s511