Abstract
Compared with the traditional Rogowski coil, printed circuit board (PCB) Rogowski coil has the advantages of high measurement accuracy, simple manufacturing process and low cost. It has become an important device in current measurement. However, the existing PCB Rogowski coils are mostly closed, and the open-ended structure PCB Rogowski coils are susceptible to external magnetic field interference. This paper proposes an open-ended structure PCB Rogowski coil based on a new winding method, so that the two open-ended PCB Rogowski coils are evenly distributed when closed, while improving the coil’s immunity to external magnetic fields based on the winding method of equal area of the de-wired and loop. In addition, this paper uses the hybrid integration circuit and the back-end matching method to achieve the broadband measurement performance of the sensor. Finally, the experimental results show that the mutual inductance difference between the closed and open-ended structure PCB Rogowski coil is less than 0.5% under the same wiring mode. Under the equivalent current interference at 50 mm from the measured current, the maximum interference coefficient of the open-ended structure coil is 1.45%; in sine sweep and pulse current test conditions, the frequency band is 34 Hz–3.5 MHz.
Highlights
Rogowski coils are widely used in high-frequency current measurement conditions because of their simple structure, good linearity, and wide measurement band [1]
In the Rogowski coil winding method, reference [3] uses two opposite printed circuit board (PCB) Rogowski coils to offset the interference caused by external magnetic fields, but due to the number of turns and doubling of layers, its frequency band will be significantly reduced
This paper proposes an improved symmetrically-wiring open-ended PCB Rogowski coil, which makes the PCB Rogowski coil have fewer holes and is easy to be mass-produced
Summary
Rogowski coils are widely used in high-frequency current measurement conditions because of their simple structure, good linearity, and wide measurement band [1]. In Reference [8], a Rogowski coil structure with differential winding design was proposed to eliminate the interference of external magnetic fields in the vertical direction. Reference [9] proposed a PCB Rogowski coil design with symmetrical double-sided wiring and equal area loop This monolithic structure avoids the interference caused by the inter-plate gap [10], but the parameter calculation is complex. In order to eliminate the interference caused by the external parallel interference magnetic field, it is necessary to ensure that the coil winding is evenly distributed when the coil is closed, the cross-sectional area is uniform, and the plane of the single-turn coil should pass through the central axis of the Rogowski coil.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have