The invention provides a health state
diagnosis early-warning circuit and method of an electric automobile high-
voltage system. The circuit comprises an
insulation resistance detection module, a connecting resistance detection module, a battery management module, a
motor control module, a pre-charging monitoring module, a
relay monitoring module and a control computing module. The modules are used for detecting an
insulation resistance value between a serial-connection
battery pack of an electric automobile and an automobile body, a connecting resistance value of a high-
voltage circuit, the health state,
voltage and current of the serial-connection
battery pack, a fault grade of a driving
motor system, voltage and current of the direct-current input end of the driving
motor system, a fault grade of a pre-charging circuit and a fault grade of a
relay on line. Quantified comprehensive representation and on-line recognition are achieved for the health state of the high-voltage
system, and therefore high-voltage safe management is performed on the safety state of the electric automobile high-voltage
system more scientifically and reasonably.