CN-121983916-A - Rapid self-adaptive multistage current limiting control method and system for BLDC (block linear direct current)

CN121983916ACN 121983916 ACN121983916 ACN 121983916ACN-121983916-A

Abstract

The invention relates to the technical field of motor control, and discloses a rapid self-adaptive multistage current limiting control method and a system for BLDC, wherein the method comprises the steps of collecting current signals and temperature signals in real time; and comparing the current signal with the dynamic current limiting threshold value to construct a multistage current limiting protection mechanism to control PWM signal output. The invention realizes the current limiting protection of the motor and solves the problems of low response speed, insufficient reliability, single protection mechanism, low intelligent degree, poor flexibility and deficient parallel processing capability in the prior art.

Inventors

HE KAI
LIN PING
HU QINGYUN
GUO PENGFEI
WANG QIANCHENG
LI GUOCUN
CHEN YUAN
WU HAO
XIA WEI

Assignees

成都凯天电子股份有限公司

Dates

Publication Date: 20260505
Application Date: 20260409

Claims (10)

1. A fast adaptive multi-stage current limit control method for BLDC, comprising the steps of: s1, collecting a current signal and a temperature signal in real time; s2, compensating the reference current limiting value by using the temperature signal through a temperature compensation self-adaptive algorithm to obtain a dynamic current limiting threshold value; s3, comparing the current signal with the dynamic current limiting threshold value to construct a multistage current limiting protection mechanism to control PWM signal output.
2. The method of claim 1, wherein the current signal comprises bus current and U/V/W phase current of the BLDC motor and the temperature signal comprises temperature of the BLDC motor and power device.
3. The method for fast adaptive multi-stage current limit control for BLDC of claim 1, wherein the step of temperature compensating the adaptive algorithm comprises: s201, constructing a temperature-current threshold mapping table, and reading the temperature signal in real time; s202, searching the corresponding current threshold value in the mapping table according to the temperature signal to serve as a reference current limit value; S203, establishing a corresponding relation between a temperature interval and a temperature coefficient, matching the temperature interval according to the temperature signal to determine the temperature coefficient, and calculating the product of the reference current limit value and the corresponding temperature coefficient to obtain the dynamic current limit threshold.
4. The fast adaptive multi-stage current limit control method for BLDC of claim 1, wherein constructing the multi-stage current limit protection scheme by comparing the current signal to the dynamic current limit threshold value, comprises: If the current signal does not exceed 120% of the dynamic current limit threshold, not intervening in the PWM signal; if the current signal exceeds 120% of the dynamic current limit threshold and does not exceed 150% of the dynamic current limit threshold, the PWM signal is not interfered, and early warning is triggered; If the current signal exceeds 150% of the dynamic current limiting threshold and does not exceed 200% of the dynamic current limiting threshold, limiting the PWM duty cycle within a preset threshold range; and if the current signal exceeds 200% of the dynamic current limiting threshold value, stopping outputting the PWM signal, and triggering protection state latching.
5. A fast adaptive multi-stage current limit control method for BLDC as set forth in claim 3, wherein the method of establishing a correspondence between the temperature interval T and the temperature coefficient K (T) includes: 。
6. a fast adaptive multi-stage current limit control system for BLDC, the system comprising: The current and temperature acquisition module is used for acquiring current signals and temperature signals in real time; the temperature compensation module is connected with the current and temperature acquisition module and is used for compensating the reference current limiting value by using the temperature signal through a temperature compensation self-adaptive algorithm to obtain a dynamic current limiting threshold value; and the current limiting decision and PWM control module is connected with the temperature compensation module and is used for constructing a multistage current limiting protection mechanism to control PWM signal output by comparing the current signal with the dynamic current limiting threshold value.
7. The fast adaptive multi-stage current limit control system for a BLDC of claim 6, wherein said current signals in said current and temperature acquisition module include bus current and U/V/W phase current of a BLDC motor, and wherein said temperature signals include temperatures of a BLDC motor and power devices.
8. The fast adaptive multi-stage current limit control system for a BLDC of claim 6, wherein the step of the temperature compensation adaptive algorithm in the temperature compensation module comprises: s201, constructing a temperature-current threshold mapping table, and reading the temperature signal in real time; s202, searching the corresponding current threshold value in the mapping table according to the temperature signal to serve as a reference current limit value; S203, establishing a corresponding relation between a temperature interval and a temperature coefficient, matching the temperature interval according to the temperature signal to determine the temperature coefficient, and calculating the product of the reference current limit value and the corresponding temperature coefficient to obtain the dynamic current limit threshold.
9. The fast adaptive multi-stage current limit control system for BLDC of claim 6, wherein the multi-stage current limit protection mechanism is constructed by comparing the current signal to the dynamic current limit threshold in the current limit decision and PWM control module, and specifically comprising: If the current signal does not exceed 120% of the dynamic current limit threshold, not intervening in the PWM signal; if the current signal exceeds 120% of the dynamic current limit threshold and does not exceed 150% of the dynamic current limit threshold, the PWM signal is not interfered, and early warning is triggered; If the current signal exceeds 150% of the dynamic current limiting threshold and does not exceed 200% of the dynamic current limiting threshold, limiting the PWM duty cycle within a preset threshold range; and if the current signal exceeds 200% of the dynamic current limiting threshold value, stopping outputting the PWM signal, and triggering protection state latching.
10. The fast adaptive multi-stage current limit control system for BLDC of claim 8, wherein in the S203, the method of establishing a correspondence of the temperature interval T and the temperature coefficient K (T) includes: 。

Description

Rapid self-adaptive multistage current limiting control method and system for BLDC (block linear direct current) Technical Field The invention relates to the technical field of motor control, and discloses a rapid self-adaptive multistage current limiting control method and system for BLDC. Background With the rapid development of power electronics technology and digital control technology, brushless direct current (BLDC) motors are widely used in fields of industrial automation, electric vehicles, aerospace, etc. due to their high efficiency, long life and good control performance. However, the BLDC may cause an overcurrent phenomenon due to abrupt load change, short circuit fault, etc. during operation, and a fast and reliable current limiting protection mechanism is required. Therefore, in BLDC control systems, current limiting protection is a critical function to ensure safe operation of the motor and drive. In the prior art, the current limiting control method of the brushless direct current motor mainly comprises the following steps of 1, a software current limiting scheme based on a Microcontroller (MCU), wherein the scheme is used for sampling a current signal through an ADC, executing a current limiting algorithm by the CPU and then adjusting output through a PWM module, 2, a current limiting scheme based on a Digital Signal Processor (DSP), wherein the processing speed of the current limiting scheme is faster than that of the MCU, but the current limiting scheme still needs to be protected through a software interrupt mechanism, and 3, an analog circuit current limiting scheme, wherein the scheme is used for realizing single-threshold overcurrent protection by analog devices such as a comparator. The current limiting control method has certain defects, wherein the response speed of the MCU-based software current limiting scheme is limited by the CPU interrupt response time and the software execution period, and is usually in the millisecond level, the DSP-based current limiting scheme has higher processing speed but still has certain response delay, and the analog circuit current limiting scheme has higher response speed but lacks flexibility, so that complex protection logic and parameter adjustment are difficult to realize. In addition, most of the existing schemes adopt fixed current limiting threshold values, and cannot be dynamically adjusted according to the actual working temperature of the motor, so that the motor is difficult to start in a low-temperature environment, and the problem of untimely protection in a high-temperature environment is solved. In summary, the existing motor current-limiting control method has obvious defects, including the problems of low response speed, insufficient reliability, single protection mechanism, low intelligent degree, poor flexibility and deficient parallel processing capability, and is difficult to meet the requirement of current-limiting protection of the motor. Disclosure of Invention Aiming at the defects in the prior art, the invention provides the rapid self-adaptive multistage current limiting control method and system for BLDC, solves the problems of low response speed, insufficient reliability, single protection mechanism, low intelligent degree, poor flexibility and deficient parallel processing capability in the prior art, and can meet the requirement of current limiting protection of a motor. The technical scheme provided by the invention comprises the following steps: A fast adaptive multi-stage current limit control method for BLDC, comprising the steps of: s1, collecting a current signal and a temperature signal in real time; s2, compensating the reference current limiting value by using the temperature signal through a temperature compensation self-adaptive algorithm to obtain a dynamic current limiting threshold value; s3, comparing the current signal with the dynamic current limiting threshold value to construct a multistage current limiting protection mechanism to control PWM signal output. Preferably, the current signal includes bus current and U/V/W phase current of the BLDC motor, and the temperature signal includes temperatures of the BLDC motor and the power device. Preferably, the step of the temperature compensation adaptive algorithm includes: s201, constructing a temperature-current threshold mapping table, and reading the temperature signal in real time; s202, searching the corresponding current threshold value in the mapping table according to the temperature signal to serve as a reference current limit value; S203, establishing a corresponding relation between a temperature interval and a temperature coefficient, matching the temperature interval according to the temperature signal to determine the temperature coefficient, and calculating the product of the reference current limit value and the corresponding temperature coefficient to obtain the dynamic current limit threshold. Preferably, the multi-stage current limitin