VOLTAGE CONTROL METHOD AND DEVICE FOR MOTOR

The present disclosure provides a method and apparatus for controlling a voltage of an electric machine, applied to a vehicle having an electricity-generation-starting-up integrated electric machine, which relates to the technical field of vehicle controlling. The method includes: when the vehicle is in a voltage-controlling mode, acquiring a current battery voltage, a current battery electric current and an electric-current limit value of the vehicle (101); according to the battery voltage, determining an initial target voltage (102); according to a difference between the electric-current limit value and the battery electric current, determining a superposing-voltage value (103); based on the superposing-voltage value and the initial target voltage, determining a target controlling voltage (104); and based on the target controlling voltage, controlling the battery voltage of the vehicle (105). Accordingly, the vehicle, even if in conditions such as a low temperature, can perform voltage-stabilization controlling by means of voltage superposition, to merely charge the low-voltage loads and the 48V section, and not perform assisting discharging, which can precisely control the voltage, and prevent over-charge and over-discharge of the battery, thereby prolonging the life of the 48V battery.