Dynamic detection and early warning method for health state of fan

Abstract

The invention provides a dynamic detection and early warning method for the health state of a fan, and belongs to the technical field of fan state monitoring, and the method comprises the steps: enabling the fan to work at a rated working frequency at a set environment temperature Te, and obtaining and recording a first steady-state temperature and a first temperature rise rate of a fan winding at each working voltage; enabling the fan to work under the rated working voltage, and respectively obtaining and recording a second steady-state temperature and a second temperature rise rate of the fan winding under each working frequency; s3, according to the first steady-state temperatures and the second steady-state temperatures, a winding temperature expression expressed by the working voltage and the working frequency is obtained, according to the first temperature rise rates and the second temperature rise rates, a winding temperature rise rate expression expressed by the working voltage and the working frequency is obtained, and the reference temperature # imgabs0 # at the nth sampling moment is obtained; and S4, when the # imgabs 1 # or the # imgabs 2 # is detected, the health state of the fan is judged to be abnormal, and early warning is carried out. The detection sensitivity and reliability can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of fan status monitoring, and in particular relates to a dynamic detection and early warning method for the health status of a fan. Background Art

[0002] Fans are commonly used heat dissipation devices in equipment. As fans operate, aging and failure are inevitable. Real-time monitoring of fan health, along with timely warnings and repairs, is crucial to stable equipment operation. Existing technologies typically monitor fan health by setting a fixed winding overtemperature threshold. For example, an alarm is triggered when the winding temperature exceeds a preset value (e.g., 80°C). However, this approach has the following drawbacks: 1. Ignoring dynamic operating conditions: Winding temperature of a fan is affected by operating voltage, frequency, and ambient temperature. Fixed thresholds cannot adapt to varying operating conditions and may result in missed alarms (e.g., in low winter temperatures, a fan may be abnormal but not reach the threshold) or false alarms (e.g., an alarm triggered by a voltage increase under normal operating conditions).

[0003] 2. Lack of early warning capability: Relying only on the absolute value of temperature, it is impossible to capture abnormal temperature rise rate (such as the slow temperature rise caused by the early stage of bearing wear). Summary of the Invention

[0004] The purpose of the present invention is to provide a dynamic detection and early warning method for the health status of a wind turbine, which can improve the detection sensitivity and reliability.

[0005] The present invention is achieved through the following technical solutions: A method for dynamic detection and early warning of the health status of a fan comprises the following steps: Step S1: Set the ambient temperature T e Under this condition, make the fan work at the rated operating frequency and step the voltage V d Adjust the operating voltage of the fan, and obtain and record the first steady-state temperature and first temperature rise rate of the fan winding at each operating voltage at the same sampling time interval. The first temperature rise rate refers to the ratio of the difference between two adjacent first steady-state temperatures to the difference between the sampling times corresponding to the two first steady-state temperatures. Step S2: Set the ambient temperature T e Under this condition, make the fan work at the rated working voltage and step the frequency f d Adjust the operating frequency of the fan, and obtain and record the second steady-state temperature and second temperature rise rate of the fan winding at each operating frequency at the same sampling time interval. The second temperature rise rate refers to the ratio of the difference between two adjacent second steady-state temperatures to the difference between the sampling times corresponding to the two second steady-state temperatures. Step S3: According to each first steady-state temperature and each second steady-state temperature, obtain the winding temperature expression represented by the operating voltage and the operating frequency; according to each first temperature rise rate and each second temperature rise rate, obtain the winding temperature rise rate expression represented by the operating voltage and the operating frequency; and according to the formula Get the n The reference temperature at the sampling moment, where Indicates that the n The winding temperature is obtained by substituting the working voltage and working frequency at the sampling time into the winding temperature expression. Indicates the n Ambient temperature at the time of sampling; Step S4: or When the fan health status is abnormal, an early warning is issued, including: Indicates the n The fan winding temperature collected at the sampling moment, Indicates the set temperature rise abnormal threshold, t represents the sampling time interval, Indicates that the n The temperature rise rate is obtained by substituting the operating voltage and operating frequency at the sampling time into the temperature rise rate expression.

[0006] Furthermore, the setting ambient temperature T e =20-30°C, and the sampling time interval is 5-20s.

[0007] Furthermore, in step S3, the least square method is used to obtain the winding temperature expression as , the expression of the winding temperature rise rate is obtained using the least squares method: ,in, V and f Represent the operating voltage and operating frequency respectively, a, b, c, d, e, p, q, r, s, y are the fitting coefficients, k 1 and k 2 respectively represent the intercept term.

[0008] Furthermore, in step S4, when the fan winding temperature at at least 6 consecutive sampling moments meets or When the fan is in an abnormal health state,

[0009] Furthermore, the first steady-state temperature, the second steady-state temperature and the first steady-state temperature of the fan winding are obtained by a first temperature sensor provided on the fan winding. n The fan winding temperature at the sampling moment is collected by the second temperature sensor set on the fan.n The ambient temperature at the sampling time.

[0010] Furthermore, the voltage step V d Set to 1V, the frequency step f d Set to 1Hz.

[0011] Furthermore, in step S1, within the allowable operating voltage range of the fan, the operating voltage of the fan is reduced and increased based on the rated operating voltage by voltage steps. In step S2, within the allowable operating frequency range of the fan, the operating frequency of the fan is reduced and increased based on the rated operating frequency by frequency steps.

[0012] The present invention has the following beneficial effects: 1. The present invention first obtains the first steady-state temperature and the first temperature rise rate of the fan winding at the rated operating frequency and different operating voltages under the set ambient temperature, obtains the second steady-state temperature and the second temperature rise rate of the fan winding at the rated operating voltage and different operating frequencies, then obtains the winding temperature expression according to each first steady-state temperature and each second steady-state temperature, obtains the winding temperature rise rate expression according to each first temperature rise rate and each second temperature rise rate, and obtains a reference temperature expression related to the winding temperature expression and the actual ambient temperature. Finally, compares whether the absolute value of the difference between the actual winding temperature and the reference temperature is greater than a set threshold, and compares whether the winding temperature change rate at two adjacent sampling moments is greater than the corresponding winding temperature rise rate for comparison. If any one of the items is met, it is determined that the fan health status is abnormal. The comparison process involves voltage, frequency, and ambient temperature, which can effectively eliminate the defect of fixed thresholds in existing technologies that make them unable to adapt to different working conditions, avoid missed reports, and improve detection sensitivity and reliability. At the same time, the temperature rise rate is taken into account, which can identify slowly developing hidden faults (such as initial bearing wear) and issue early warnings. It can also detect sudden faults (such as local short circuits in windings), abnormal mechanical loads (such as impeller imbalance), and heat dissipation failures (such as dust accumulation) and issue timely warnings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will be further described in detail below with reference to the accompanying drawings.

[0014] Figure 1 Flowchart of the present invention. DETAILED DESCRIPTION

[0015] like Figure 1 As shown, the dynamic detection and early warning method of the wind turbine health status includes the following steps: Step S1: Set the ambient temperature T eUnder this condition, make the fan work at the rated operating frequency and step the voltage V d Adjust the operating voltage of the fan, and obtain and record the first steady-state temperature and first temperature rise rate of the fan winding at each operating voltage at the same sampling time interval. The first temperature rise rate refers to the ratio of the difference between two adjacent first steady-state temperatures to the difference between the sampling times corresponding to the two first steady-state temperatures. Specifically, in this embodiment, the ambient temperature of the standard working condition is used as the set ambient temperature, that is, T e =25℃, the sampling interval is set to 10s, and within the allowable operating voltage range of the fan (V 0-a To V 0+b ), with voltage step V d =1V. Reduce and increase the operating voltage of the fan based on the rated operating voltage V0, and record the first steady-state temperature and the first temperature rise rate in Table 1. Among them, t represents the time required for the winding temperature rise to stabilize when the operating voltage changes, that is, the sampling time interval: Table 1 Step S2: Set the ambient temperature T e Under this condition, make the fan work at the rated working voltage and step the frequency f d Adjust the operating frequency of the fan, and obtain and record the second steady-state temperature and second temperature rise rate of the fan winding at each operating frequency at the same sampling time interval. The second temperature rise rate refers to the ratio of the difference between two adjacent second steady-state temperatures to the difference between the sampling times corresponding to the two second steady-state temperatures. Specifically, within the allowable operating frequency range of the fan ( f 0-a to f 0+b ), with frequency steps f d =1Hz at rated operating frequency f 0, and record the second steady-state temperature and the second temperature rise rate in Table 2: Table 2 Step S3: According to each first steady-state temperature and each second steady-state temperature, obtain the winding temperature expression represented by the operating voltage and the operating frequency; according to each first temperature rise rate and each second temperature rise rate, obtain the winding temperature rise rate expression represented by the operating voltage and the operating frequency; and according to the formula Get the n The reference temperature at the sampling moment, where Indicates that the n The winding temperature is obtained by substituting the working voltage and working frequency at the sampling time into the winding temperature expression. Indicates the n Ambient temperature at the time of sampling; The expression for winding temperature obtained by least square method is: , the expression of winding temperature rise rate is obtained by using the least square method: ,in, V and f Represent the operating voltage and operating frequency respectively, a, b, c, d, e, p, q, r, s, y are the fitting coefficients, k 1 and k 2 respectively represent the intercept term.

[0016] In this embodiment, the first steady-state temperature, the second steady-state temperature and the first steady-state temperature of the fan winding are obtained by a first temperature sensor provided on the fan winding. n The fan winding temperature at the sampling moment is collected by the second temperature sensor set on the fan. n The ambient temperature at the sampling time.

[0017] Step S4: or When the fan health status is abnormal, an early warning is issued, including: Indicates the n The fan winding temperature collected at the sampling moment, Indicates the set temperature rise abnormal threshold, t represents the sampling time interval, Indicates that the n The temperature rise rate is obtained by substituting the operating voltage and operating frequency at the sampling time into the temperature rise rate expression; In order to avoid false alarms, when the fan winding temperature meets the or When the fan is in an abnormal health state,

[0018] The above description is merely a preferred embodiment of the present invention and therefore cannot be used to limit the scope of the present invention. In other words, equivalent changes and modifications made according to the scope of the patent application and the contents of the specification should still fall within the scope of the patent of the present invention.

Claims

1. A method for dynamic detection and early warning of wind turbine health status, characterized by: The steps include: Step S1: Set the ambient temperature T e Under this condition, make the fan work at the rated operating frequency and step the voltage V d Adjust the operating voltage of the fan, and obtain and record the first steady-state temperature and first temperature rise rate of the fan winding at each operating voltage at the same sampling time interval. The first temperature rise rate refers to the ratio of the difference between two adjacent first steady-state temperatures to the difference between the sampling times corresponding to the two first steady-state temperatures. Step S2: Set the ambient temperature T e Under this condition, make the fan work at the rated working voltage and step the frequency f d Adjust the operating frequency of the fan, and obtain and record the second steady-state temperature and second temperature rise rate of the fan winding at each operating frequency at the same sampling time interval. The second temperature rise rate refers to the ratio of the difference between two adjacent second steady-state temperatures to the difference between the sampling times corresponding to the two second steady-state temperatures. Step S3: According to each first steady-state temperature and each second steady-state temperature, obtain the winding temperature expression represented by the operating voltage and the operating frequency; according to each first temperature rise rate and each second temperature rise rate, obtain the winding temperature rise rate expression represented by the operating voltage and the operating frequency; and according to the formula Get the n The reference temperature at the sampling moment, where Indicates that the n The winding temperature is obtained by substituting the working voltage and working frequency at the sampling time into the winding temperature expression. Indicates the n Ambient temperature at the time of sampling; Step S4: or When the fan health status is abnormal, an early warning is issued, including: Indicates the n The fan winding temperature collected at the sampling moment, Indicates the set temperature rise abnormal threshold, t represents the sampling time interval, Indicates that the n The temperature rise rate is obtained by substituting the operating voltage and operating frequency at the sampling time into the temperature rise rate expression.

2. The method for dynamic detection and early warning of the health status of a wind turbine according to claim 1, characterized in that: The set ambient temperature T e =20-30°C, and the sampling time interval is 5-20s.

3. The method for dynamic detection and early warning of the health status of a wind turbine according to claim 1, characterized in that: In step S3, the least square method is used to obtain the winding temperature expression: , the expression of the winding temperature rise rate is obtained using the least squares method: ,in, V and f Represent the operating voltage and operating frequency respectively, a, b, c, d, e, p, q, r, s, y are the fitting coefficients, k 1 and k 2 respectively represent the intercept term.

4. A method for dynamic detection and early warning of the health status of a wind turbine according to claim 1, 2 or 3, characterized in that: In step S4, when the fan winding temperature at at least 6 consecutive sampling moments meets the or When the fan is in an abnormal health state, 5. A method for dynamic detection and early warning of the health status of a wind turbine according to claim 1, 2 or 3, characterized in that: The first steady-state temperature, the second steady-state temperature and the first steady-state temperature of the fan winding are obtained by a first temperature sensor arranged on the fan winding. n The fan winding temperature at the sampling moment is collected by the second temperature sensor set on the fan. n The ambient temperature at the sampling time.

6. A method for dynamic detection and early warning of wind turbine health status according to claim 1, 2 or 3, characterized in that: The voltage step V d Set to 1V, the frequency step f d Set to 1Hz.

7. A method for dynamic detection and early warning of wind turbine health status according to claim 1, 2 or 3, characterized in that: In step S1, within the allowable operating voltage range of the fan, the operating voltage of the fan is reduced and increased based on the rated operating voltage by voltage steps. In step S2, within the allowable operating frequency range of the fan, the operating frequency of the fan is reduced and increased based on the rated operating frequency by frequency steps.

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