Braking method and system of frequency converter

The invention discloses a braking method and system of a frequency converter. The method is applied to a motor speed regulation system consisting of a frequency converter and a motor, and includes thesteps of entering a braking mode; acquiring the initial output frequency Ps and output current Is of the frequency converter and the initial speed Vt of the motor when entering the braking mode; regulating the output frequency of the frequency converter to a target frequency Pt and maintaining the target frequency Pt, wherein Pt=0.1*Ps; and detecting the speed Vm of the motor, and regulating theoutput frequency of the frequency converter to 0 when Vm=0.5*Vt, wherein the frequency converter maintains the output current Iz until the motor stops rotating, Iz