In fields such as new energy storage, automotive three-electric system testing, industrial automation, power measurement and control, and high-end equipment R&D, current sensors are core components for electrical signal acquisition, equipment condition monitoring, system safety protection, and precise power calculation. The accuracy of sensor selection directly determines the measurement precision, operational stability, and long-term reliability of the entire system.
The market offers a wide variety of current-sensor technologies, each with its own performance trade-offs: Hall-effect sensors, fluxgate sensors, differential transformers, Rogowski coils, CT-based current transformers, shunt-based sampling, and magnetoresistive sensors. Many projects commonly suffer from issues such as improper sensor selection, mismatched accuracy, and poor suitability for the operating conditions. As…Domestic current sensorWith continuous technological iteration and upgrades, domestic solutions now fully address all application scenarios—covering both high and low precision, AC and DC operation, wide and narrow bandwidths, and large and small measurement ranges. Leveraging advantages such as high cost-effectiveness, short delivery times, customized services, and localized technical support, these solutions are gradually replacing imported products and have become the preferred choice for equipment integration across various industries.
This article focuses on the mainstream 7 high-current sensing technology approach, systematically outlining the selection logic across five key dimensions—core principles, performance advantages, limitations, applicable operating conditions, and the advantages of domestic solutions—to help R&D engineers, equipment purchasers, and system integrators make quick and accurate selections.
I. Open-loop Hall current sensor
open-loop Hall-effect sensors operate based on the Hall magnetic-electric effect. They use a Hall element to sense changes in the magnetic field of a current-carrying conductor, linearly converting the magnetic-field signal into a voltage output. This enables isolated measurement of AC, DC, and pulsed currents, making it the most widely used basic sensing solution in industrial applications today.
This solution features a streamlined architecture, compact size, extremely low power consumption, and controllable costs, with excellent mass-production compatibility. However, it is significantly affected by core hysteresis and ambient temperature, exhibiting moderate temperature drift; its measurement accuracy and linearity are at an average level, making it unsuitable for demanding test scenarios requiring high precision and stability.
Advantages of domestic solutions: Domestic open-loop Hall-effect sensors feature mature manufacturing processes, stable quality control, and a full range of standardized measurement ranges, enabling large-scale supply. Compared with imported products, they offer an exceptional cost advantage while also supporting small-batch custom modifications, perfectly meeting the needs of general industrial mass production.
II. Closed-loop Hall current sensor
Closed-loop Hall (magnetic balance) sensors are an upgraded version of open-loop designs, featuring a compensation coil and a closed-loop feedback circuit. They counteract the magnetic field generated by the measured current through reverse compensation, keeping the magnetic core in a zero-flux equilibrium state at all times, thereby thoroughly addressing the hysteresis and linearity shortcomings of open-loop solutions.
Its core advantages include fast response speed, wide bandwidth, excellent linearity, strong resistance to electromagnetic interference, and full compatibility with both AC and DC measurements. With well-balanced overall performance, it is the mainstream solution for mid- to high-end industrial equipment; its only shortcoming is that zero-point drift under low-current conditions still has room for optimization.
Advantages of domestic solutions: Domestic closed-loop Hall sensors have achieved breakthroughs in the localization of core chips, magnetic core materials, and circuit algorithms. Their accuracy, bandwidth, and temperature drift performance are on par with imported counterparts, while offering superior cost-effectiveness and faster delivery cycles, making them well-suited to meet the mass-production needs of various mid- to high-end industrial control devices.
III. Fluxgate Current Sensor: A Benchmark Solution for High-Precision DC Measurement
fluxgate current sensors represent the core technological approach for high-precision current measurement today. Unlike the Hall-effect sensing principle, they rely on the periodic excitation and saturation characteristics of a soft magnetic core to precisely detect minute changes in magnetic fields, and use a dedicated demodulation circuit to reconstruct an accurate current signal. The closed-loop zero-flux architecture can reduce residual flux in the core to zero.
The greatest advantage of this technology isDC measurement accuracy is extremely high, zero-point drift is extremely low, and long-term stability is excellent.It can achieve ultra-high-precision measurements at the ppm level and is capable of detecting minute DC current variations; its drawbacks are relatively limited bandwidth, higher structural and circuit complexity, and a higher cost compared to Hall-effect solutions.
Advantages of domestic solutions: Breaking the foreign high-end monopoly, domestically produced fluxgate sensors have achieved technological breakthroughs in low temperature drift, high stability, and long lifespan, making them perfectly suited for various precision testing applications. They also support customized range, accuracy, and structural development, with localized after-sales technical services that are more efficient.
IV. Differential Current Sensor
differential current sensor adopts a dual-core symmetrical differential structure, with two sets of cores having completely identical parameters paired with oppositely connected coils. It operates on the principle of electromagnetic induction, features no excitation circuit, and keeps the magnetic core unsaturated throughout its operation, making it a specialized optimization solution developed to address industry-specific pain points.
Its core value lies in its ability to completely counteract the magnetic core saturation caused by DC bias, accurately measuring the AC component superimposed on the DC. This thoroughly resolves the measurement distortion and saturation failure issues that conventional current transformers and Hall sensors experience under conditions with DC bias; however, it is limited in that it cannot measure pure DC current on its own.
Advantages of the domestic solution: The domestically produced differential sensor optimizes the magnetic core matching process for the complex industrial conditions in China, achieving higher symmetry, better cancellation performance, and stronger resistance to magnetic bias. It is also tailored to meet the specific operating requirements of domestic inverters and power equipment.
V. Rogowski Coil
The Rogowski coil features a hollow, coreless structure, with no magnetic saturation or hysteresis error, and boasts core advantages such as extremely wide bandwidth, fast response speed, unlimited measurement range, flexible openable design, and convenient installation, making it specifically suited for measuring high-frequency, large-current, and transient pulse currents.
This scheme cannot directly measure DC current; it outputs a current derivative signal and must be paired with a dedicated integrator circuit to reconstruct the original waveform, making it suitable only for AC and transient pulse conditions.
Advantages of the domestic solution: The domestically produced Rogowski coil features a refined winding process, high coil uniformity, excellent measurement linearity, and strong compatibility with integration circuits. It can be custom‑made to specified lengths, diameters, and accuracies, making it suitable for various high‑power industrial testing applications.
VI. Electromagnetic Current Transformer CT
Traditional electromagnetic CTs operate on the principle of electromagnetic induction; they feature a passive structure, mature technology, high stability, and require no maintenance. They are classic auxiliary devices for power systems operating at power frequency, primarily used to achieve low-voltage sampling of large currents and electrical energy measurement.
Its inherent limitation is its inability to measure pure DC current; when a DC component is present in the operating conditions, core saturation and excessive measurement errors are highly likely, and residual magnetism can persistently affect measurement accuracy. It is suitable only for stable power-frequency AC operating conditions.
Advantages of domestic solutions: Domestic CT transformers offer a complete product range and a high degree of standardization. The core material has been optimized for power grid operating conditions, significantly enhancing anti-interference performance and stability, fully meeting the conventional metering and protection requirements of both residential and industrial power applications.
VII. Shunt Resistor Sampling
shunt sampling is based on Ohm’s law; it uses a high-precision sampling resistor in series with the circuit to measure the voltage across the resistor and convert it into a current signal. This design is extremely simple, free from hysteresis errors, offers fast response, and has very low cost.
’s core shortcoming is its lack of electrical isolation; under high-current conditions, it suffers from severe heat loss and low safety, making it suitable only for simple sampling scenarios involving low voltage, small current, and on-board integration.
Advantages of domestic solutions: Domestic high-precision shunt resistors feature low temperature drift and stable accuracy, making them suitable for on-board PCB integration. They can be mass-supplied to support small power supplies and lightweight electric
The core of selecting a current sensor for is not blindly pursuing high precision, but rather ensuring operational-condition suitability, performance alignment, and cost control. Currently, domestic current-sensor technology has reached full maturity, covering all application scenarios from general industrial use to high-end precision testing. With its core advantages of technological independence, outstanding cost-effectiveness, flexible customization, and efficient service, it has become a key enabler for equipment localization and quality upgrades across various industries, providing reliable underlying sensing support for power measurement, industrial automation, and high-end new-energy equipment.