Active short-circuit method for preventing torque impact

Abstract

The invention discloses an active short-circuit method for preventing torque impact. The method comprises the following steps: using a direct-current high-voltage detection circuit to detect a direct-current bus voltage, using a speed detection circuit to detect a rotating speed of a motor, and if the bus voltage reaches a voltage threshold value or the received rotating speed of the motor reachesa speed threshold value, entering an active short-circuit mode; providing a PWM waveform with a very small duty ratio for three transistors of a high-voltage side bridge arm in a three-phase bridge type inverter circuit, and turning off the three transistors of a low-voltage side bridge arm; gradually increasing the duty ratio of the PWM waveform of the three transistors of the high-voltage sidebridge arm; when the duty ratio of the PWM waveform of the three transistors of the high-voltage side bridge arm reaches a preset value, making the three transistors of the high-voltage side bridge arm be all switched on; and if the rotating speed of the motor is lower than a rated rotating speed, making the three transistors of the high-voltage side bridge arm be all turned off, sealing waves andstopping. A variable duty ratio method is adopted, the torque impact is reduced, driving comfort performance is improved, and a vehicle power system and personal safety are protected.

Description

technical field [0001] The invention belongs to the technical field of motor control software algorithms, and in particular relates to an active short-circuit method for preventing torque impact. Background technique [0002] At this stage, most electric vehicles will adopt an active short circuit method to prevent further damage to the system after the motor control system is out of control, thereby protecting the power system. However, the active short-circuit method will generate a large torque impact, which will cause the vehicle to vibrate violently and affect the comfort performance. Contents of the invention [0003] The technical problem to be solved by the present invention is to provide an active short-circuit method for preventing torque shock in view of the above-mentioned deficiencies in the prior art. This active short-circuit method for preventing torque shock adopts a method of variable duty ratio to reduce torque shock , improve driving comfort, protect v...

AI Technical Summary

Problems solved by technology

However, the active short-circuit method will generate a large torque impact, whi

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