Load electric quantity sensor

The utility model provides a load electric quantity sensor, comprising an electric quantity acquiring module and a display control module. The electric quantity acquiring module is divided into an electromagnetic isolation unit, an electricity conversion unit, an MCU1 unit, a communication unit, an MCU2 unit, a configuring unit and a power supply unit. The electric quantity acquiring module respectively isolates and acquires voltage and current signals of a three-phase asynchronous motor through an electromagnetic isolation acquire unit; the processed signals are transmitted to the electricity conversion unit for calculating and then sent to the MCU1 unit; the processed signals are transmitted to the MCU2 unit in the display control module through the communication unit of the module; the MCU2 unit calculates the actual load weight of the motor in the working process by fitting a mathematical model of the load in combination with the power; and finally the load weight is output by the configuring unit via the RS485 bus. The load electric quantity sensor can be used for real-time monitoring electric quantities of voltage, current, power and the like of the three-phase asynchronous motor, and can fit the real-time load weight when the motor of the headstock gear is working.