Electrical energy generator and automatic measurement circuit thereof

An electrical energy generator, having an input end connected to alternating current (AC) power of a power grid, and an output end connected to an electrical component, the electrical energy generator comprising:

• a rectifying and filtering circuit configured to rectify and filter AC power of the power grid;
• an automatic measurement circuit including:
• a discharge loop, having a switch and a discharge resistor connected in series, the discharge resistor discharging electrical energy generated by the electrical energy generator;
• a control circuit configured to control opening and closing of the switch, wherein, before the electrical energy generator supplies power to the electrical component, the control circuit is configured to control the switch to close for a first duration to perform discharging through the discharge resistor;
• a bus voltage measurement circuit configured to acquire a bus voltage value outputted by the rectifying and filtering circuit;
• and
• a discharge current measurement circuit configured to acquire a discharge resistor current value of a discharge process of the first duration, wherein the first duration is greater than or equal to one period of a rectified waveform, and wherein the discharge current measurement circuit is configured to measure a voltage across the discharge resistor;
• and
• a calculator configured to calculate an internal resistance of the power grid based on the bus voltage and the voltage across the discharge resistor.