针对目前风电机组健康状态无法准确评估的问题,提出一种基于多参数融合和组合赋权的风电机组健康状态评估方法.根据故障频次与时长构建风电机组健康状态评估指标体系,通过将灰色关联分析法的参数层指标客观权重与层次分析法的参数层主观权重对应结合,再与上层指标权重综合,归一化得到组合指标权重,应用高斯函数确定指标对各状态等级的隶属度,采用参数-部件-系统逐层对风电机组开展健康状态评估,选取新疆某风电机组SCADA数据进行验证.结果表明:该方法可在故障发生前得出状态劣化的趋势,对机组早期的故障发出报警,从而达到整机状态预警的目的.

针对仅用时域和频域指标无法准确诊断滚动轴承故障的问题,提出一种基于灰色关联度(GRA)与偏最小二乘(PLS)的故障诊断算法.首先,对原始振动信号进行灰色关联度分析,提取关联度较高的振动信号作为样本信号;其次,通过时域分析和频域分析获得故障特征集,利用基于遗传算法(GA)和Elman神经网络的组合算法(GA-ENN)对故障特征进行提取;最后,利用PLS算法对滚动轴承的故障类别进行识别.实验结果表明,所提方法能有效剔除原始振动信号中无信息变量,并且实现时、频域指标下滚动轴承故障的准确诊断.

In order to improve the accuracy of the whole blood hemoglobin (Hb) concentration prediction model, the original whole blood transmission spectrum signals were first preprocessed by using centering, auto scaling, standard normal variate (SNV), multiplicative scatter correction (MSC), and Savitzky-Golay (SG) smoothing combined with MSC. And the best preprocessing effect was obtained with a R2 value of 0. 9441 by using SG smoothing combined with MSC. The width of the SG smoothing window was discussed, and the optimal width is 27. The baseline shift of the whole blood absorbance signals was eliminated, and the signal-to-noise ratio was improved after data preprocessing. The 190 samples were divided into a calibration set (corresponding Hb concentrations from 10. 6 to 17. 3 g.dL(-1)) of 143 samples and a validation set (corresponding Hb concentrations from 10. 3 to 17. 3 g.dL(-1)) of 47 samples. The model's applicability was ensured when two sets have a similar distribution and range of Hb concentrations. And then, the Monte Carlo uninformative variable elimination (MC-UVE) was used to select the informative wavelength, which simplified the model structure and increased the proportion of useful wavelengths. When the Monte Carlo iteration number was 1000, 191 wavelength points were selected from the 700 wavelengths of the whole blood absorbance spectrum to build the whole blood Hb concentration partial least squares (PLS) model. Finally, a comparison was performed among the model based on the original whole blood transmission spectrum, the model based on the whole blood absorbance spectrum, the SG-MSC-PLS model, the SG-MSC-MC-UVE-PLS model and an existing model. In addition to this, the number of selected wavelengths based on MC-UVE was much smaller than the total number, but the predictive effect was much better, which was beneficial to improve the calculation efficiency of the model. The results indicate that the SG-MSC-MC-UVE-PLS method effectively increases the signal-to-noise ratio of the whole blood absorption spectrum signal and simplifies the model. Besides, our procedure's prediction accuracy and calculation efficiency of the model was improved by our procedure, which has reference significance for the development of hemoglobin concentration detection technology.