A multi-functional lightning current and vibration monitoring system and device for wind turbines

Abstract

The present invention discloses a multifunctional lightning current and vibration monitoring system and device for a wind turbine, aiming to solve the problems of excessive workload of the microprocessor and low judgment accuracy in the prior art. The technical solution of the present invention is as follows: A multifunctional lightning current and vibration monitoring system for a wind turbine includes a lightning current signal acquisition module and a vibration signal acquisition module; the lightning current signal acquisition module and the vibration signal acquisition module are respectively connected to the microprocessor module, and the storage module, the alarm module, and the communication module are respectively interconnected with the microprocessor module. The present invention can completely and accurately collect the relevant data of the lightning current of the blades and the equipment in the nacelle of the wind turbine and the vibration information of the equipment in the nacelle, compare the data of the vibration information and the lightning information with the set parameters after analysis and processing, and give an alarm in time when the set value is not met, thereby improving the accuracy of predicting the faults of the wind turbine.

Description

Technical Field

[0001] The present invention belongs to the technical field of equipment monitoring and diagnostic analysis, and particularly relates to a multi-functional lightning current and vibration monitoring system and device for a wind turbine generator set. Background Art

[0002] Wind turbine generator sets are often installed in isolated environments with relatively complex climatic conditions. Moreover, as tall and prominent objects on the ground, due to these factors, the possibility of wind turbine generator sets being struck by lightning is greatly increased. The energy released by lightning in a short time causes great damage to wind turbine generator sets, and at the same time increases the maintenance difficulty and cost.

[0003] In previous lightning monitoring devices for wind turbine generator sets, the lightning acquisition method cannot accurately and completely obtain relevant data of lightning signals. Using a single vibration signal or a single lightning current signal to judge whether the wind turbine generator set is faulty and the degree of damage has a low accuracy rate. Therefore, it fails to give an alarm in time and accurately to notify maintenance personnel to take corresponding maintenance measures, which further causes the continuous development of faults and affects the safe operation of wind turbine generator sets. Summary of the Invention

[0004] The purpose of the present invention is to provide a multi-functional lightning current and vibration monitoring system and device for a wind turbine generator set, which solves the problem of the excessive workload of the microprocessor caused by a large amount of lightning information collected at a low sampling frequency in the prior art, and the low accuracy rate of judging the faults and damage degree of the wind turbine generator set by a single vibration information or a single lightning information.

[0005] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0006] A multi-functional lightning current and vibration monitoring system for a wind turbine generator set includes a lightning current signal acquisition module, a vibration signal acquisition module, a microprocessor module, a storage module, an alarm module, and a communication module; the lightning current signal acquisition module includes a self-integrating Rogowski coil sensor, a lightning current signal conditioning module, a change-over switch, and a triple ADC module, which are connected in sequence; the vibration signal acquisition module includes an acceleration sensor, a vibration signal conditioning module, and an ADC module; the lightning current signal acquisition module and the vibration signal acquisition module are respectively connected to the microprocessor module, and the storage module, the alarm module, and the communication module are respectively interconnected with the microprocessor module.

[0007] The lightning current signal at the corresponding monitoring point and the vibration signal in the nacelle of the wind turbine are collected by using a self-integrating Rogowski coil sensor and an acceleration sensor. The signals are preprocessed through the corresponding conditioning modules. When performing analog-to-digital conversion on the lightning current signal, a "triple parallel sequential operation" ADC module is adopted, that is, the acquisition process of the entire lightning current signal is divided into three stages, and each stage is completed by 1 ADC module with different conversion times and sampling frequencies. Its microprocessor calculates and processes the collected lightning current signal and vibration signal respectively to obtain the characteristic parameter indexes of the lightning current signal and the characteristic parameter indexes of the fan vibration signal, compares them with the set values. When the set values are not met, the alarm module is started for alarm, and various characteristic parameter indexes obtained are uploaded to the background monitoring center by using the communication module.

[0008] The device monitors the lightning current parameters in real time online and simultaneously monitors the time-domain indexes of the vibration signal, such as peak value X p , mean value root mean square value (effective value) X rms , kurtosis index K, waveform factor W s , peak factor C f , impulse index I, margin coefficient L and skewness S and other parameter indexes as well as frequency-domain indexes.

[0009] The conversion switch and the "triple parallel sequential operation" ADC module are set with i m = 3KA as the threshold value. According to experience, the lightning current amplitude I m is determined, and 50%I m is set as a threshold value. The acquisition process of the lightning current is divided into 4 stages: T0, T1, T2, and T3. As Figure 2 shown. Under normal circumstances, the ADC1 sampling module of the system works in the T0 stage and samples at the sampling frequency f0. When it is detected that the lightning current reaches i≥i m , it enters the T1 stage, and still uses the ADC1 sampling module to switch the sampling frequency f0 to the sampling frequency f1. When it is detected that the lightning current rises to i≥50%I m , it enters the T2 stage, and its microcontroller controls the conversion switch to be adjusted from the ADC1 sampling module to the ADC2 sampling module, and the sampling frequency is f2 at this time. When it is detected that the lightning current signal drops to i≤50%I m , it enters the T3 stage. The microcontroller controls the conversion switch to be adjusted to the ADC3 sampling module and samples at the sampling frequency f3. Until the lightning current i≤i m , the sampling of the lightning current ends.

[0010] A multi-functional lightning current and vibration monitoring device for wind turbines, comprising a lightning current signal acquisition module, a vibration signal acquisition module, a microprocessor module, a storage module, an alarm module and a communication module; the lightning current signal acquisition module includes a self-integrating Rogowski coil sensor, a lightning current signal conditioning module, a change-over switch and a triple ADC module; the vibration signal acquisition module includes an acceleration sensor, a vibration signal conditioning module and an ADC module;

[0011] The self-integrating Rogowski coil sensors are respectively arranged on the blades, gearboxes and generators of the wind turbines; the acceleration sensors are respectively arranged on the main shaft bearings, low-speed bearings of the gearboxes, high-speed bearings of the gearboxes, front bearings of the generators and rear bearings of the generators in the wind turbines, and are connected to the corresponding conditioning modules; the lightning current signal conditioning module, the vibration signal conditioning module, the ADC module, the microprocessor module, the storage module, the alarm module and the communication module are integrated together and arranged in the nacelle of the wind turbine.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] The present invention can completely and accurately collect the relevant data of the lightning current of the blades and the equipment in the nacelle of the wind turbine and the vibration information of the equipment in the nacelle. After analysis and processing, the vibration information and the lightning information data are compared with the set parameters. When the set value is not met, an alarm is given in time, so as to improve the accuracy of predicting the faults of the wind turbine. At the same time, even when the wind turbine is not damaged by lightning, the vibration information collected in real time can be used as the basis for judging whether the wind turbine is damaged. And when the wind turbine is struck by lightning but there is no vibration information generated by the equipment in the nacelle of the wind turbine, the damage degree of the wind turbine can be judged by the single lightning information at this time, realizing real-time online monitoring and diagnostic analysis, thereby reducing the maintenance time and ensuring the normal operation of the wind turbine. When collecting the lightning current signal, the "triple parallel sequential operation" ADC module is used, and it is adjusted to the corresponding ADC module through the change-over switch. By using the acquisition methods with different sampling frequencies and conversion times, this acquisition method reduces the workload of the microprocessor in processing a large amount of data and also provides data basis for the subsequent design of the lightning protection measures of the wind turbine. Description of the Drawings

[0014] Figure 1 is the overall structural block diagram of the present invention;

[0015] Figure 2 is the schematic diagram of collecting the lightning current signal of the present invention;

[0016] Figure 3 is the hardware connection diagram of the change-over switch and the "triple parallel sequential operation" ADC module;

[0017] Figure 4 Flow chart for collecting lightning current in the present invention. Specific embodiments

[0018] The present invention will be further described in detail below in conjunction with specific embodiments, but the implementation manners of the present invention include, but are not limited to, the scope represented by the following embodiments.

[0019] As Figure 1 shown, it is a structural diagram of a multi-functional lightning current and vibration monitoring device for a wind turbine, including a lightning current signal acquisition module, a vibration signal acquisition module, a microprocessor module, a storage module, an alarm module, and a communication module. The output ends of the lightning current signal acquisition module and the vibration signal acquisition module are respectively connected to the input end of the microprocessor, and the input ends of the storage module, the alarm module, and the communication module are respectively connected to the output end of the microprocessor. The self-integrating Rogowski coil sensor and the acceleration sensor are used to collect the lightning current signal at the corresponding monitoring point and the vibration signal in the nacelle of the wind turbine, and the corresponding conditioning module is used to preprocess the signal and convert it into the range allowed by the ADC module. The microprocessor calculates and processes the collected lightning current signal and vibration signal respectively to obtain the characteristic parameter indexes of the lightning current signal and the characteristic parameter indexes of the wind turbine vibration signal. When the set parameters are not met, the alarm module is started for alarm. And the various characteristic parameter indexes obtained are uploaded to the background monitoring center by using the communication module.

[0020] The lightning current acquisition module therein includes a self-integrating Rogowski coil sensor, a lightning current signal conditioning module, a changeover switch, and a "triple parallel sequential operation" ADC module. The self-integrating Rogowski coil sensor is used to collect the lightning current signal at the monitoring point and convert it into a 0-±10V low voltage signal. The lightning current low voltage signal is further processed by the lightning current signal conditioning module and transformed into the voltage range allowed by the ADC sampling module. Then, the changeover switch is adjusted to the corresponding ADC sampling module to sample the lightning current signal.

[0021] The vibration acquisition module includes an acceleration sensor, a vibration signal conditioning module, and an ADC module. The acceleration sensor is used to collect the vibration signal at the monitoring point. After a series of measures such as amplifying, filtering, integrating, and isolating the vibration signal by the vibration signal conditioning module, the vibration signal is transformed into the range that the ADC sampling module can receive, and then the vibration signal is sampled.

[0022] As Figure 2 shown, i m = 3KA is set as the threshold value, and 50%I m (I m is the current amplitude) is set as a threshold value, and the collection of the lightning current signal is divided into four stages. From the normal situation to i = i mWhen (i is the collected current), it is the T0 stage; from i = i m rising to i = 50%I m is the T1 stage; from i = 50%I m falling to the occurrence of the next i = 50%I m is the T2 stage; from i = 50%I m until i = i m is the T3 stage.

[0023] As Figure 3 shown, under normal circumstances, the ADC1 sampling module operates in the T0 stage and samples at the sampling frequency f0. When the collected current signal reaches the limit condition of i ≥ i m , it enters the T1 stage, and still uses the ADC1 sampling module. At this time, the sampling frequency is converted from f0 to f1. When the collected lightning current signal rises to the condition of i ≥ 50%I m , it enters the T2 stage. The switch is adjusted from the ADC1 sampling module to the ADC2 sampling module and samples at the sampling frequency f2. When the collected lightning current signal drops to the condition of i ≤ 50%I m , it enters the T3 stage. The switch is adjusted from the ADC2 sampling module to the ADC3 sampling module, and the sampling frequency is switched from f2 to f3.

[0024] As Figure 4 shown, under normal circumstances, the ADC1 sampling module operates in the T0 stage and samples at the sampling frequency f0. In this stage, it is judged whether the collected information is a lightning current. If the condition of i ≥ i m is not satisfied, the above steps are repeated. When this condition is met, it enters the T1 stage. At this time, the ADC1 sampling module continues to sample at the sampling frequency f1, and then judges whether the collected lightning current satisfies the limit condition of i ≥ 50%I m . If not, the ADC1 sampling module continues to sample at the sampling frequency f1. When this condition is met, it enters the T2 stage, uses the ADC2 sampling module to sample at the sampling frequency f2, and judges whether the collected lightning current satisfies the limit condition of i ≤ 50%I m . If not, the ADC2 sampling module continues to sample at the sampling frequency f2. When it is met, it enters the T3 stage, uses the ADC3 sampling module to sample at the sampling frequency f3. When the collected lightning current signal satisfies the condition of i ≤ i m , the sampling of the lightning current signal ends. Otherwise, the ADC3 sampling module still samples at the sampling frequency f3.

Claims

1. A multi-functional lightning current and vibration monitoring system for a wind turbine, characterized in that: It includes a lightning current signal acquisition module, a vibration signal acquisition module, a microprocessor module, a storage module, an alarm module and a communication module; the lightning current signal acquisition module includes a self-integrating Rogowski coil sensor, a lightning current signal conditioning module, a switch and a triple ADC module which are connected in sequence; the vibration signal acquisition module includes an acceleration sensor, a vibration signal conditioning module and an ADC module; the lightning current signal acquisition module and the vibration signal acquisition module are respectively connected to the microprocessor module, and the storage module, the alarm module and the communication module are respectively interconnected with the microprocessor module; The conversion switch and the "triple parallel sequential operation" ADC module are set with i m = 3KA as the threshold value. According to experience, the lightning current amplitude I m is determined, and 50%I m is set as a threshold value; the acquisition process of the lightning current is divided into 4 stages: T0, T1, T2, and T3. Under normal circumstances, the ADC1 sampling module of the system operates in the T0 stage and samples at the sampling frequency f0; when it is detected that the lightning current reaches i≥i m , it enters the T1 stage, still using the ADC1 sampling module, and switches the sampling frequency f0 to the sampling frequency f1; when it is detected that the lightning current rises to i≥50%I m , it enters the T2 stage, and the microprocessor controls the conversion switch to be adjusted from the ADC1 sampling module to the ADC2 sampling module. At this time, the sampling frequency is f2; when it is detected that the lightning current signal drops to i≤50%I m , it enters the T3 stage; the microprocessor controls the conversion switch to be adjusted to the ADC3 sampling module and samples at the sampling frequency f3; until the lightning current i≤i m , the sampling of the lightning current ends; The self-integrating Rogowski coil sensor and the acceleration sensor are used to acquire the lightning current signal at the corresponding monitoring point and the vibration signal in the nacelle of the wind turbine. The signals are preprocessed by the corresponding conditioning modules. When performing analog-to-digital conversion on the lightning current signal, a "triple parallel sequential operation" ADC module is adopted, that is, the acquisition process of the entire lightning current signal is divided into three stages, and each stage is completed by 1 ADC module with different conversion times and sampling frequencies. The microprocessor calculates and processes the acquired lightning current signal and vibration signal respectively to obtain the characteristic parameter indexes of the lightning current signal and the characteristic parameter indexes of the wind turbine vibration signal, and compares them with the set values. When the set values are not met, the alarm module is started to give an alarm, and the various characteristic parameter indexes obtained are uploaded to the background monitoring center by using the communication module.

2. The multi-functional lightning current and vibration monitoring system for a wind turbine according to claim 1, characterized in that: The system monitors the lightning current parameters online in real time and simultaneously monitors the time-domain indexes of the vibration signals online.

3. A multi-functional lightning current and vibration monitoring device for a wind turbine according to the system described in claim 1 or 2, characterized in that: It includes a lightning current signal acquisition module, a vibration signal acquisition module, a microprocessor module, a storage module, an alarm module and a communication module; the lightning current signal acquisition module includes a self-integrating Rogowski coil sensor, a lightning current signal conditioning module, a switch and a triple ADC module; the vibration signal acquisition module includes an acceleration sensor, a vibration signal conditioning module and an ADC module; The self-integrating Rogowski coil sensors are respectively arranged on the blades, gearboxes and generators of the wind turbine; the acceleration sensors are respectively arranged on the main shaft bearing, low-speed bearing of the gearbox, high-speed bearing of the gearbox, front bearing of the generator and rear bearing of the generator in the wind turbine, and are connected to the corresponding conditioning modules; the lightning current signal conditioning module, the vibration signal conditioning module, the ADC module, the microprocessor module, the storage module, the alarm module and the communication module are integrated and arranged in the nacelle of the wind turbine.

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