Abstract:According to the mathematical model of permanent magnet synchronous motor, this paper uses the analytical method to obtain the current and torque equation of the permanent magnet synchronous motor under the active shortcircuit operation in different working conditions, and reveals the relationship between the motor output and motor parameters. The results are verified by simulations and experiments. The significance of this paper is that the advantages and disadvantages of using active shortcircuiting as a safety shutoff path is analyzed theoretically, and the current calculation formula for permanent magnet synchronous motor under active shortcircuit condition is proposed, which provides a basis for the motor controller to select a suitable power device.