Introduction to the functional principle of the split current sensor -

The split current sensor has unique advantages in terms of ease of use, and it is almost a fixed choice, especially in the field measurement occasions that do not allow interruption. The split current sensors on the market are mainly based on the Hall principle or Rogowski coils. Due to the limited working principle, the accuracy is generally not high, and can only achieve about 1%. Products with an accuracy level of 0.1% or higher are widely required in fields such as power measurement, but current products cannot meet the performance requirements. In order to provide customers with perfect solutions, Hunan Yinhe Electric Co., Ltd. has developed the SCI series of high-precision split current sensors, whose accuracy greatly exceeds the traditional split solutions, even higher than the mainstream non-split solutions. At present, the full-scale accuracy of our SCI series split-type sensors is 0.1% and 0.02%, the range covers 100A to 5000A, and the measurement frequency ranges from DC to hundreds of kHz. High-precision split-type current sensors. 2. The design principle of the split-type sensor The traditional split-type current sensor, whether based on the Hall principle or the Rogowski coil, cannot achieve high accuracy in theory. Sensors based on the Hall principle, even the non-opening closed-loop Hall sensor with high precision, the upper limit of accuracy is only about 0.3%, and the accuracy will further decrease if it is made into an open-closed type. The disadvantage of the Rogowski coil is also that the accuracy is not high, and the flexible Rogowski coil can only achieve 1%, and there are other obvious disadvantages, such as the inability to measure DC, poor low-frequency characteristics, poor waveform quality, and obvious phase delay. The high-precision open-close current sensor belongs to the DC current converter (Direct Coupled Current
Transformer, DCCT) is a new generation of isolated current measurement device, which can measure DC, AC or pulse current, and has a high level of test accuracy. In addition to the advantages of isolated measurement, it also has a series of significant advantages such as wide measurement dynamic range, high measurement accuracy, wide frequency range, fast response speed, and basically not affected by external environments such as temperature. Compared with the previous generation Hall resistive current sensor, it has a qualitative improvement in performance. The basic principle of our SCI series sensors is based on the new magnetic modulation zero flux technology, which compensates the influence of the bus current on the magnetic ring by driving the feedback current, realizes the measurement of the zero magnetic flux state in the magnetic ring, and realizes a nearly ideal bus current- Output current ratio. The SCI series of high-precision open-close current sensors apply the principle of zero magnetic flux, and through superior modulation and demodulation design ideas, the high performance of this series of sensors is guaranteed in principle; through efficient self-recovery logic, high reliability under complex working conditions is realized. Sex; by optimizing the process of manufacturing and processing, to achieve excellent product performance and ease of use. 3. High-precision open-close current sensor index test For the performance test of the SCI series high-precision open-close current sensor, our company selects the high-precision current sensor that has been calibrated by the China Institute of Metrology and awarded a calibration certificate for comparison test, but due to the comparison method The intuition is poor. On the basis of ensuring the accuracy of the split current sensor, our company uses the source meter method to test it, so that customers can see it at a glance. We selected the high-precision open-close current sensor SCI-600 with a range of 600A and a full-scale accuracy index of 0.02% for testing. As shown in Figure 3 and Figure 4, we choose our company's self-developed DC high-current source SCS-1500AU with a full scale of 1500A and an accuracy of 0.01% as the test DC current source, and use the eight-and-a-half-digit meter as the test meter, and select the voltage file (Here we choose Vishay series resistors with a calibrated resistance value of 1.000006Ω as the load resistance for testing). 4. Advantages The SCI series split current sensor adopts a split-type through-hole structure, and provides a variety of measurement apertures and ranges to choose from. It does not need to disconnect the busbar under test, which is convenient for installation and measurement. It is mainly for DC, AC and pulse current measurement fields that require high measurement accuracy.
, The secondary current is isolated from each other, and the safety performance is superior. Features Open and close, easy to install and measure Advanced zero-flux closed-loop current sensor Excellent linearity and accuracy Extremely low temperature drift Wide frequency band and low response time Primary and secondary side isolation measurement Strong anti-interference ability