Protection circuit with functions of upper limit and lower limit

The invention relates to a protection circuit with functions of upper limit and lower limit, which is arranged on a motor controller of an electric vehicle, which comprises 12 parts, namely an A (DSP (digital signal processing) minimum system), a B (U-phase current sensor), a C (V-phase current sensor), a D (W-phase current sensor), an E (voltage sensor), an F (U-phase current upper/lower limit fault processing circuit), a G (V-phase current upper/lower limit fault processing circuit), an H (W-phase current upper/lower limit fault processing circuit), an I (voltage upper/lower limit fault processing circuit), a J (CPLD (complex programmable logic device)), a K (fault indicating circuit) and an L (three-phase bridge arm driving circuit). The protection circuit responds and processes faults such as over-voltage, under-voltage, over-current and the like quickly, avoids potential hazards such as dead halt and the like when software can not track in time or the system works abnormally, and simultaneously improves the protection level and enables the system safety to be higher.