Second-order sliding mode observation-based fan power control method and system

1. A second-order sliding mode observation-based fan power control method, characterized by comprising:

calculating, by second-order sliding mode observation, an observed rotational speed value of a fan, and calculating a maximum power reference current corresponding to maximum power of the fan according to a relational expression between the rotational speed and maximum power point; and

performing, by controlling a Pulse Width Modulation (PWM) switch to be toggled, system Maximum Power Point Tracking (MPPT) according to the maximum power reference current, so as to control the fan to operate stably at the maximum power point.

2. The second-order sliding mode observation-based fan power control method of claim 1 , further comprising:

constructing a second-order sliding mode differential estimator using a second-order sliding mode algorithm, so as to obtain a current error differential signal.

3. The second-order sliding mode observation-based fan power control method of claim 2 , further comprising:

constructing a current error signal differential estimator using a super-twisting algorithm.

4. The second-order sliding mode observation-based fan power control method of claim 3 , further comprising:

processing, by two parallel linearly independent first-order current models, a neutral point voltage of a brushless direct-current motor of the fan into a state space form of line voltage.

5. The second-order sliding mode observation-based fan power control method of claim 4 , further comprising:

forming, by a line current error of the brushless direct-current motor, a sliding mode surface.

6. A second-order sliding mode observation-based fan power control system, characterized by comprising:

a second-order sliding mode observer, configured to calculate, by second-order sliding mode observation, an observed rotational speed value of a fan, and calculate a maximum power reference current corresponding to maximum power of the fan according to a relational expression between the rotational speed and maximum power point; and

a tracking controller, configured to perform, by controlling a Pulse Width Modulation (PWM) switch to be toggled, system Maximum Power Point Tracking (MPPT) according to the maximum power reference current, so as to control the fan to operate stably at the maximum power point.

7. The second-order sliding mode observation-based fan power control system of claim 6 , wherein the second-order sliding mode observer is configured to:

construct a differential estimator using a second-order sliding mode algorithm, so as to obtain a current error differential signal.

8. The second-order sliding mode observation-based fan power control system of claim 7 , wherein the second-order sliding mode observer is configured to:

construct a current error signal differential estimator using a super-twisting algorithm.

9. The second-order sliding mode observation-based fan power control system of claim 8 , wherein the second-order sliding mode observer is configured to:

process, by two parallel linearly independent first-order current models, a neutral point voltage of a brushless direct-current motor of the fan into a state space form of line voltage.

10. The second-order sliding mode observation-based fan power control system of claim 9 , wherein the second-order sliding mode observer is configured to:

form, by a line current error of the brushless direct-current motor, a sliding mode surface.