基于谐波分析的电磁流量计信号处理方法

Signal processing method of electromagnetic flowmeter based on harmonic analysis

为了提出适用于不同介质和工况的基于谐波分析的电磁流量计信号处理方法,针对在不同的浆液流量测量现场需要重新确定某个高次谐波作为与流速成线性关系的特征量的问题,给出了具体的选择方法。针对在水标定时存在零点过大的问题,对数据进行去微分处理。在基于数字信号处理(DSP)的电磁流量变送器上实时实现信号处理方法。进行水流量标定和对纸浆流量信号的处理。实验结果表明,测量水流量时满足0.5级精度,测量纸浆流量时计算波动<5%,响应时间<5s,验证了该方法的有效性和普遍适用性。

In order to propose a signal processing method based on harmonic analysis suitable for different media and working conditions, it is necessary to reselect a higher-order harmonic as characteristic variable linearly related to the flow for different slurry flow measurement sites, and a selection method is given. Aiming at the problem that the zero point is too large in the water calibrating, the problem is solved by de-differentiating the data. The signal processing method is realized in the DSP-based hardware system of electromagnetic flowmeter. The experimental results of water flow calibration and slurry flow signal processing show that the accuracy meets level 0. 5 when measuring water flow. The fluctuation of calculation results is less than 5% and the response time is less than 5 seconds when measuring slurry flow. The effectiveness and general applicability of the method are verified.