Voltage sag detection method, device and equipment and storage medium

The invention discloses a voltage sag detection method and device, equipment and a storage medium. The method comprises the following steps: acquiring a d-axis component and a q-axis component of a three-phase power grid voltage in a rotating coordinate system according to an actual value of each phase of power grid voltage in the three-phase power grid voltage; performing phase shifting on the q-axis component by a preset angle, and then superposing the q-axis component with the d-axis component to obtain a first output result; the actual value of each phase of power grid voltage is subjected to phase shifting by a preset angle and then is superposed with the corresponding actual value of each phase of power grid voltage, and a second output result is obtained; and performing logical operation on the first output result and the second output result to obtain a voltage sag detection result. Because the occurrence of the voltage sag has randomness and rapidness, the voltage sag detection method in the applicat