Fuzzy PID (Proportion Integration Differentiation) adaptive control method for auxiliary fan in fan performance test system
By using fuzzy PID adaptive control and a two-way communication mechanism between the host computer and the frequency converter, the problems of slow nozzle switching response and insufficient stability of traditional PID control in the fan performance testing system are solved. This enables fast, stable, and precise airflow adjustment of the auxiliary fan, improving the robustness and response speed of the testing system.
Patent Information
- Application Number
- CN202511409302.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-29
- Publication Date
- 2025-11-18
AI Technical Summary
In existing wind turbine performance testing systems, nozzle switching methods suffer from slow response and limited adjustment accuracy. Traditional PID control methods exhibit large overshoot, slow convergence, and insufficient stability under nonlinear and disturbance environments. Furthermore, the lack of real-time feedback between the auxiliary wind turbine and the host computer system results in insufficient closed-loop adjustment accuracy and robustness.
A fuzzy PID adaptive control method is adopted, combined with a two-way communication mechanism between the host computer and the frequency converter. The PID parameters are corrected by fuzzy logic to realize the dynamic optimization control of the auxiliary fan. The actual air volume is calculated in real time using a differential pressure sensor and compared with the target air volume in a closed loop to form an adaptive control closed loop.
It enables rapid, stable, and precise adjustment of the auxiliary fan's output air volume, improving the stability and response speed of the test conditions. It is suitable for test scenarios with multiple operating conditions and multiple air volume ranges, and improves the degree of automation and test efficiency.
Smart Images
Figure CN120972503A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a fuzzy PID adaptive control method for an auxiliary fan in a fan performance testing system. It is applied to the fan performance testing system to achieve high-precision airflow regulation and stable test condition control, and belongs to the field of fan performance testing technology. Background Technology
[0002] Fan performance testing is a crucial step in evaluating a fan's aerodynamic performance and energy efficiency. Current testing systems commonly use nozzle switching to set test conditions. However, nozzle switching suffers from drawbacks such as coarse intervals, slow response, and limited adjustment precision, making it difficult to quickly obtain the target airflow in nonlinear and highly turbulent testing environments.
[0003] To compensate for insufficient nozzle adjustment, auxiliary fans are often introduced as a secondary adjustment method to achieve more precise airflow control. However, traditional PID control methods rely on fixed parameters, and under the influence of fan nonlinear characteristics and environmental disturbances, they often suffer from large overshoot, slow convergence, and insufficient stability. Furthermore, auxiliary fans are typically driven by frequency converters, and the interaction between existing host computer systems and frequency converters is mostly unidirectional control, lacking real-time feedback on operating status, resulting in insufficient closed-loop regulation accuracy and robustness.
[0004] Therefore, there is an urgent need for a closed-loop control method that combines fuzzy logic and adaptive PID, and based on the two-way communication mechanism between the host computer and the frequency converter, to correct the control parameters in real time, thereby achieving rapid, stable and precise adjustment of the auxiliary fan's output air volume to meet the high precision requirements of the fan performance testing system. Summary of the Invention
[0005] The purpose of this invention is to propose a fuzzy PID adaptive control method for an auxiliary fan in a fan performance testing system. By correcting the PID parameters through fuzzy logic and combining the bidirectional communication mechanism between the host computer and the frequency converter, the method can achieve dynamic optimization control of the output air volume of the auxiliary fan, thereby improving the stability and response speed of the test conditions.
[0006] The specific technical solution adopted in this invention is as follows:
[0007] A fuzzy PID adaptive control method for an auxiliary fan in a fan performance testing system is proposed. This method is applied to the fan performance testing system and achieves precise adjustment of the auxiliary fan by introducing a fuzzy PID adaptive control strategy in the host computer control stage. Its main process includes: (1) setting the target air volume Qtarget; (2) the differential pressure sensor collects the differential pressure data in the test pipeline in real time and calculates the air volume according to the air volume calculation formula specified in GB-T1236-2017. Obtain the actual air volume Q acutual =Q vWhere ε is the expansion coefficient, taken as 1; a i For the flow coefficient, refer to Table 4 of GB-T1236-2017; d i ρ is the nozzle throat diameter (m); Δp is the differential pressure gauge reading (Pa); α This refers to the ambient density (kg / m³) under operating conditions. Where p α Atmospheric pressure (Pa); p ν The partial pressure of water vapor is approximately 0 Pa; t α (3) The host computer calculates the deviation e between the target air volume and the actual air volume and its rate of change Δe; (4) Input the deviation e and the rate of change Δe into the fuzzy controller. The fuzzy controller outputs the correction amount ΔKp, ΔKi, and ΔKd of the PID parameters according to the preset membership function and rule base; (5) The host computer updates the PID controller parameters according to the correction amount to form new Kpnew, Kinew, and Kdnew, and calculates the control amount u(t) accordingly; (6) The control amount is sent to the inverter through RS485 communication. The inverter adjusts the speed of the auxiliary fan according to the received frequency command, thereby changing the output air volume; (7) The host computer receives the operating frequency of the inverter through RS485 and performs feedback judgment in conjunction with Qactual to form closed-loop control; (8) If the actual air volume meets the stability condition, that is, |Qtarget-Qactual|≤0.05*Qtarget and the error does not fluctuate significantly within a continuous period of time, the air volume is considered to be stable. Otherwise, return to step (3) to continue adjustment.
[0008] The advantages and positive effects of this invention are as follows:
[0009] (1) The fuzzy PID method is used to realize the adaptive control of the auxiliary fan, which overcomes the shortcomings of the fixed parameters of the traditional PID and improves the robustness and dynamic response capability of the control system.
[0010] (2) Introduce a two-way communication mechanism between the host computer and the frequency converter to realize the integration of command issuance and operation status feedback, and ensure the real-time performance and accuracy of adjustment.
[0011] (3) Calculate the actual air volume based on the differential pressure sensor and compare it with the target air volume in a closed loop to ensure that the output air volume converges quickly and remains stable.
[0012] (4) The method is applicable to wind turbine performance testing systems of different specifications and has good versatility and scalability. Attached Figure Description
[0013] To more clearly illustrate the technical solution of the present invention, the accompanying drawings, as part of the embodiments, are used to further describe the present invention, wherein:
[0014] Figure 1 This is a flowchart of the fuzzy PID adaptive control method for the auxiliary fan in the fan performance testing system of the present invention.
[0015] Figure 2 This is a framework diagram of the application scenario of the fuzzy PID adaptive control method for the auxiliary fan in the fan performance testing system of the present invention. Detailed Implementation
[0016] The present invention will be further illustrated below with reference to the accompanying drawings and embodiments. However, these embodiments are merely illustrative, and the scope of protection of the present invention is not limited to these embodiments.
[0017] Combination Figure 1 , Figure 2 The auxiliary fan fuzzy PID adaptive control method in the fan performance testing system of the present invention is described in detail as follows: Figure 1 As shown, this invention introduces a fuzzy logic adjustment stage into the traditional PID control framework, forming an adaptive control process. The system first uses a differential pressure sensor to collect the differential pressure signal at the auxiliary fan outlet in real time, and calculates the current actual airflow value using a formula. This actual airflow is compared with the set target airflow to generate the deviation and the rate of change of deviation, both of which serve as inputs to the fuzzy controller. The fuzzy controller infers from the input based on preset membership functions and a rule base, outputting PID parameter correction values to achieve online adjustment of the proportional coefficient Kp, integral coefficient Ki, and derivative coefficient Kd. The corrected PID controller outputs a new control quantity, which is transmitted to the frequency converter via RS485 communication protocol to drive the auxiliary fan speed adjustment, thereby enabling the actual airflow to quickly approach the target value and ensuring stable setting of the test conditions.
[0018] like Figure 2 As shown, the application framework of this invention mainly consists of a host computer, a frequency converter, an auxiliary fan, and a differential pressure sensor. The host computer, as the control core, is responsible for running the fuzzy PID algorithm and establishing bidirectional communication with the frequency converter via an RS485 bus: on the one hand, it issues control frequency commands to adjust the speed of the auxiliary fan in real time; on the other hand, it receives operating frequency information fed back from the frequency converter and monitors the execution results. The differential pressure sensor is installed in the air duct of the auxiliary fan, collecting airflow-related signals in real time and feeding them back to the host computer for control calculations. This closed-loop structure can maintain a fast dynamic response and stable steady-state output under external disturbances, load fluctuations, or changes in set operating conditions, thereby improving the reproducibility of operating conditions and the accuracy of data during fan performance testing.
[0019] In practical applications, this invention can be deployed on fan performance testing platforms that meet the requirements of standards such as ISO 5801-2017, GB / T 17713-2022, and GB / T1236-2017. By introducing fuzzy PID adaptive control, the airflow adjustment accuracy of the auxiliary fan is significantly improved. The testing system can quickly set and stably maintain the target airflow, thereby reducing fluctuations and deviations caused by manual adjustment or fixed parameter control. This method is particularly suitable for testing scenarios with multiple operating conditions and multiple airflow ranges, and can significantly improve the degree of automation and testing efficiency.
[0020] The above examples are only for the purpose of helping to understand the core idea of the present invention; at the same time, those skilled in the art will know that there will be changes in the specific implementation methods and application scope based on the idea of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.
Claims
1. A fuzzy PID adaptive control method for assisting a fan in a fan performance test system, characterized in that: The method comprises the following steps: S1, setting a target air volume Qtarget and collecting an actual air volume Qactual in real time; S2, calculating an air volume deviation e=Qtarget-Qactuale and a change rate Δe of the air volume deviation; S3, inputting the deviation e and the change rate Δe into a fuzzy inference engine to perform online PID parameter tuning to obtain updated PID parameters Kpnew, Kinew, and Kdnew; S4, performing PID control calculation based on the updated PID parameters to obtain a control amount u(t); S5, driving an auxiliary fan to perform adjustment according to the control amount to obtain an adjusted actual air volume Qadjusted; and S6, judging whether an air volume stability condition is met: when |Qtarget-Qadjusted|≤0.05*Qtarget is met, outputting a test end instruction, otherwise, returning to step S2 to continue execution. The deviation calculation and the change rate calculation of the deviation are both completed based on the air volume data collected in real time.
2. The method of claim 1, wherein: The fuzzy inference engine outputs a correction amount of the PID parameters according to a combination of the deviation e and the change rate Δe of the deviation, and updates the original PID parameters.
3. The method of claim 1, wherein: The PID control calculation adopts a proportional, integral, and differential superposition mode to generate the control amount.
4. The method of claim 1, wherein: The adjusted air volume Qadjusted obtained after the auxiliary fan performs adjustment is collected in real time and fed back to the air volume deviation calculation module to form a closed loop control.
5. The method of claim 1, wherein: When the air volume error satisfies |Qtarget-Qadjusted|≤0.05*Qtarget, it is determined that the air volume is stable, and the test is ended.
6. The method according to any one of claims 1 to 5, characterized in that: