US 11,927,608 B1
AC/DC closed-loop current sensor
Peng Li, Guangzhou (CN); Qiancheng Lv, Guangzhou (CN); Bing Tian, Guangzhou (CN); Xiaopeng Fan, Guangzhou (CN); Zhong Liu, Guangzhou (CN); Zhiming Wang, Guangzhou (CN); Renze Chen, Guangzhou (CN); Jie Wei, Guangzhou (CN); Xu Yin, Guangzhou (CN); Zejie Tan, Guangzhou (CN); Zhenheng Xu, Guangzhou (CN); Senjing Yao, Guangzhou (CN); Licheng Li, Guangzhou (CN); Yuehuan Lin, Guangzhou (CN); Shengrong Liu, Guangzhou (CN); Bofeng Luo, Guangzhou (CN); and Jiaming Zhang, Guangzhou (CN)
Assigned to DIGITAL GRID RES. INST., CHINA SOUTHERN PWR. GRID, Guangzhou (CN)
Filed by DIGITAL GRID RES. INST., CHINA SOUTHERN PWR. GRID, Guangzhou (CN)
Filed on Sep. 18, 2023, as Appl. No. 18/369,353.
Claims priority of application No. 202211330609.6 (CN), filed on Oct. 26, 2022.
Int. Cl. G01R 19/00 (2006.01); G01R 15/20 (2006.01)
CPC G01R 19/0092 (2013.01) [G01R 15/205 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An AC/DC closed-loop current sensor, comprising: a magnetism gathering iron core, a TMR chip, a sampling circuit, a bandpass filtering circuit, a DC filtering circuit, a selection circuit, a signal amplification circuit, a signal generator, and a feedback coil, wherein the TMR chip is arranged at an air gap of the magnetism gathering iron core, the sampling circuit is connected to the TMR chip, the bandpass filtering circuit, and the DC filtering circuit respectively, the selection circuit is connected to the bandpass filtering circuit, the DC filtering circuit, and the signal amplification circuit respectively, the signal amplification circuit is connected to the signal generator, the feedback coil is wound around the magnetism gathering iron core and connected to the signal generator;
wherein the magnetism gathering iron core is configured to converge an induced magnetic field based on a measured current, the TMR chip is configured to output an induced signal based on the induced magnetic field, the sampling circuit is configured to sample and process the induced signal, the bandpass filtering circuit and the DC filtering circuit are configured to select a current signal component from the induced signal, the selection circuit is configured to select the current signal component, the signal amplification circuit is configured to amplify the current signal component to obtain the current signal component and send the current signal component to the signal generator, and the signal generator is configured to adjust a current output to the feedback coil based on the current signal component, and output a measurement result of the selected current signal component;
wherein the bandpass filtering circuit is a dual-phase lock-in amplification circuit, the dual-phase lock-in amplification circuit adopts a lock-in amplifier with dual-phase phase-sensitive detection technology, a parallel lock-in amplifier is set on the lock-in amplifier, and a 90° phase shift is added to the parallel lock-in amplifier; the dual-phase lock-in amplification circuit uses a cross-correlation characteristic of a reference signal and a sample signal to extract a sample signal component with the same frequency and phase as the reference signal.