Fan speed control method and fan speed control module

Abstract

A fan speed control method first defines multiple first control temperature difference values ​​and multiple second control temperature difference values, then extracts a first selected control temperature difference value and a second selected control temperature difference value, and then defines multiple temperature ranges based on a desired temperature value, the first selected control temperature difference value, and the second selected control temperature difference value. Next, a proportional-integral-derivative (PID) calculation formula and a proportional-derivative (PDD) calculation formula are established. Then, a temperature detection element is used to detect a measured temperature value and a temperature change trend of a working element. Finally, based on the temperature change trend and the temperature range corresponding to the measured temperature value, a PLD value is calculated using either the PID calculation formula or the PLD calculation formula.

Claims

1. A fan speed control method, used to selectively combine at least two of a proportional calculation term, an integral calculation term, and a differential calculation term to calculate a pulse width modulation value, thereby controlling the speed of a fan to dissipate heat from a working element in a working system with a preset desired temperature value, and the fan speed control method comprising the following steps: (A) establishing a correlation between a working mode and a temperature difference value based on the working system, thereby defining a plurality of first control temperature difference values ​​and a plurality of second control temperature difference values ​​corresponding to a plurality of working modes of the working system, wherein each corresponding first control temperature difference value is less than a second control temperature difference value; (B) selecting a selected working mode from among the working modes, thereby retrieving a corresponding first selected control temperature difference value and a second selected control temperature difference value; (C) Adding the desired temperature value to the first selected control temperature difference value defines a first upper critical temperature value (SV+a); adding the desired temperature value to the second selected control temperature difference value defines a second upper critical temperature value (SV+b); subtracting the desired temperature value from the first selected control temperature difference value defines a first lower critical temperature value (SV-a); subtracting the desired temperature value from the second selected control temperature difference value defines a second lower critical temperature value (SV-b); (D) Establish a proportional-integral-differential calculation formula and a proportional-differential calculation formula, wherein, The proportional-integral-differential (PID) formula includes the proportional term, the integral term, and the differential term; the proportional-differential formula includes the proportional term and the differential term; (E) Detect a measured temperature value and a temperature change trend of the working element using a temperature sensing element; (F) Based on the detection result of step (E), when the temperature change trend is increasing and the measured temperature value is less than SV-b, calculate the pulse width modulation value according to the PID formula; when the temperature change trend is increasing and the measured temperature value is between SV-b and SV+a, calculate the pulse width modulation value according to the PID formula; when the temperature change trend is increasing and the measured temperature value is between SV+a and SV+b, calculate the pulse width modulation value according to the PID formula; when the temperature change trend is increasing and the measured temperature value is greater than SV+b, increase the fan speed to a maximum speed; and (G) Based on the detection results of step (E), when the temperature change trend is decreasing and the measured temperature value is less than SV-a, the fan speed is adjusted according to the proportional-integral-differential formula; when the temperature change trend is decreasing and the measured temperature value is between SV-a and SV+a, the fan speed is adjusted according to the proportional-integral-differential formula; when the temperature change trend is decreasing and the measured temperature value is between SV+a and SV+b, the fan speed is adjusted according to the proportional-integral-differential formula; when the temperature change trend is decreasing and the measured temperature value is greater than SV+b, the fan speed is increased to the maximum value.

2. The fan speed control method as described in claim 1, wherein, The first control temperature difference values ​​in step (A) are between 1 and 2 (°C), and the second control temperature difference values ​​are between 5 and 10 (°C).

3. A fan speed control module for executing the fan speed control method as described in claim 1, the fan speed control module comprising: a storage unit for storing the relationship between the operating mode and the temperature difference value; A processing unit, electrically connected to the storage unit and the temperature sensing element, and having built-in proportional-integral-derivative (PID) and proportional-derivative (PDD) formulas, is used to extract a first selected control temperature difference value and a second selected control temperature difference value from the relationship between the selected operating mode and the temperature difference value, based on the selected operating mode. It then defines a first upper critical temperature value (SV+a), a second upper critical temperature value (SV+b), a first lower critical temperature value (SV-a), and a second lower critical temperature value (SV-b) based on the desired temperature value, the first selected control temperature difference value, and the second selected control temperature difference value. This allows for comparison of the measured temperature value with the temperature ranges corresponding to SV+a, SV+b, SV-a, and SV-b, and the calculation of the pulse width modulation (PWM) value using the PID formulas. A pulse width modulator, electrically connected to the processing unit and the fan, is used to control the fan speed based on the PWM value.

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