DC bus current estimation method based on motor controller

Abstract

The invention discloses a DC bus current estimation method based on a motor controller. The DC bus current estimation method comprises the following steps of: S1, extracting a key quantity of a motor control system; S2, performing filtering processing on a control vector; S3, calculating alternating current side electric power; S4, judging a working state of a motor; S5, acquiring the efficiency of a controller; and S6, calculating the current of a direct-current bus. By the adoption of the DC bus current estimation method, calculation of the direct-current bus current does not need to depend on a current sensor, estimation is conducted only based on key data of an existing control system of the permanent magnet synchronous motor, meanwhile, the accurate bus current is calculated in combination with the accurate efficiency result of a synchronous motor rack calibration test, the bus current calculation precision reaches + / -1%, the cost of the motor controller is reduced, the bus current detection precision is improved, and the high-voltage safety and reliability of the electric automobile are improved.

Description

technical field [0001] The invention relates to the technical field of permanent magnet synchronous motor control for new energy vehicles, and more specifically, to a method for estimating DC bus current based on a motor controller. Background technique [0002] In the field of electric vehicle motor control, although the DC bus current is not the direct object of control, as a key quantity reflecting the charging and discharging of power batteries, it can also be used as an important reference quantity for the safety of high-voltage electric vehicles. Motor controllers are generally required on vehicles The real-time transmission of the DC bus current requires the controller hardware to be equipped with a DC bus current detection sensor and a detection circuit, which increases the cost of hardware components and occupies the AD channel resources of the DSP. The hardware itself has detection accuracy errors and failure risks. , will cause the controller to detect bus current...

AI Technical Summary

Problems solved by technology

[0002] In the field of electric vehicle motor control, although the DC bus current is not the direct object of control, as a key quantity reflecting the charging and discharging of power batteries, it can also be used as an important reference quantity for the safety of high-voltage electric vehicles. Motor controllers are generally required on vehicles The real-time transmission of the DC bus current requires the controller hardware to be equipped with a DC bus current detection sensor and a detection circuit, which increases the cost of hardware components and occupies the AD channel resources of the DSP. The hardware itself has detection accuracy errors and failure risks. , will cause the controller to detect bus current function and performance defects, and even affect the driving safety of electric vehicles in severe cases

Images