_

In some applications, the need to speed down, according to the principle of asynchronous motor, the greater the greater the torque, the same brake torque will increase with the increase of the speed rate of the system, so that the system can greatly shorten the time to reduce the speed, the DC bus voltage is rapidly rising, so the feedback energy quickly dissipated, and maintain the DC bus voltage in a certain range of security. The main function of the brake unit system is to quickly consume the energy (the energy is dissipated by the brake resistance). It effectively makes up the general inverter brake at slow speed, braking torque is small (less than or equal to 20% of the rated torque) of the shortcomings and to a few need to brake quickly but lower frequency is well suited.