High/Low Voltage Power Switching Based on Dual-Loop Constant Current Control for Electromagnetic Flowmeter Excitation Control System
YANG Shuang-long1,WANG Gang2,XU Ke-jun1,3,SHI Lei2,LI Ji-chun2
1.School of Electrical and Automation Engineering, Hefei University of Technology, Hefei, Anhui 230009, China
2.Chongqing Sichuan Automation Co. Ltd., Chongqing 404001, China
3.Engineering Technology Research Center of Industrial Automation, Anhui Province, Hefei, Anhui 230009, China
Abstract Based on the simulation analysis of constant excitation current control,a novel method of dual-loop control for constant excitation current control is proposed in order to improve high-frequency square wave excitation performance of the electromagnetic flowmeter. This method includes an outer loop for high/low voltage power switching and an inner loop for current fine-tuning,which can ensure zero satiability of the sensor output signal and high power efficiency of the excitation system when electromagnetic flowmeter is excited by high-frequency square wave. A square wave excitation control system is designed to realize to excite the coil by high frequency precisely. The simulation results show that the higher the high voltage power,the more widely the excitation frequency can be expanded. The experimental results show that the speed of constant excitation current control is fast and the sensor output signal of the electromagnetic flowmeter has steady zero when the excitation system is excited by high-frequency square wave.
YANG Shuang-long,WANG Gang,XU Ke-jun, et al. High/Low Voltage Power Switching Based on Dual-Loop Constant Current Control for Electromagnetic Flowmeter Excitation Control System[J]. Acta Metrologica Sinica, 2011, 32(3): 193-197.
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2011, Vol. 32 
