In October 2024, the "2024 Fourth xEV Battery Technology Forum & the Second Solid-State Battery Technology Industry Conference" was grandly held in Jiading, Shanghai. At the conference, Mr. Zeng Fenglin, General Manager of Innosense Electronics, introduced an innovative high-precision open-loop Hall current sensor solution. This solution directly addresses the industry pain points in the application field of new energy vehicle battery packs, effectively resolving the issue of insufficient accuracy in open-loop Hall sensors while ensuring functional safety. It helps customers achieve cost reduction and efficiency improvement, thereby creating value for them.
01 Industry pain point analysis
Before releasing the product, Zeng Fenglin systematically expounded on the pain points of the industry at present.
First, [Demand for accurate detection of small currents in sentinel mode]
At present, a large proportion of new energy vehicles are equipped with sentinel mode. In this mode, the vehicle current is extremely low, only a few amperes. While when the battery pack is in normal operation, the current is as high as hundreds to thousands of amperes. Therefore, the current sensor needs to have the ability to accurately measure both large currents and small currents (a few amperes) with high precision, so as to avoid the long-term error in sentinel mode affecting the estimation of battery remaining capacity (SOC) and battery management strategies.
Second, [Hidden danger of overheating during fast charging]
Fast charging technology has always been a focal topic that attracts much attention in the industry. The reason behind it is self-evident. Whether it is 5C or 6C, it means a significant increase in charging current, but at the same time, it may also cause a safety hazard of overheating of the battery pack.
Third, [Cost]
Cost determines an enterprise's profit margin, market competitiveness and sustainable development.
Fourth, [Functional Safety]
At present, the development of sensors that meet functional safety requirements still faces many challenges.
02 Innosense's Solution
In response to the industry pain points and challenges mentioned above, after years of dedicated research and focused efforts, Innosense has successfully launched an innovative high-precision current sensor solution based on open-loop Hall technology.
When compared to existing sensors on the market, Innosense's current sensor solution offers the following advantages:
First: [High precision]
At present, although the open-loop Hall sensor on the market has a low cost, generally, the accuracy is not very high. It only has an accuracy of about 1%-3%.
Innosense sensor: Zero drift at room temperature ≤ 50mA, accuracy 0.2%; zero drift over full temperature range ≤ 100mA, accuracy 0.5%. Actual test data shows stable full-scale accuracy, with excellent performance in both high and low currents, particularly with errors for currents below 20A consistently within 50mA.
How can open-loop Hall technology achieve high-precision detection?
The key lies in Innosense's unique technical know-how:
First: Adopt digital-analog hybrid technology.
Different from traditional analog circuits, by combining digital circuits, errors can be better compensated and the results are more accurate.
Secondly: temperature drift compensation
Temperature drift is one of the main errors of traditional Hall sensors. However, the temperature can be measured and the temperature drift curve is stable, so it is relatively easy to compensate.
Third: Magnetic error compensation
Magnetic error is another major source of error for traditional Hall sensors and is difficult to compensate. It is usually considered unmeasurable and the working conditions are changeable. The core technical advantage of Shensi lies in realizing sensor magnetic error compensation through compensation algorithms. This is the key technology for high-precision measurement of open-loop Hall sensors.
Finally: Perform segmented calibration on the sensor.
Innosense conducts multi-point calibration specifically for sensors within a measurement range of 20A, which is the key to ensuring the accuracy of small current measurements.
Second: [Controllable temperature rise]
For high currents, Innosense conducted a copper bar temperature rise test, which is complex. Based on the conditions and standards set through communication with customers, Innosense tested the temperature rise of the sensor copper bar (dimensions: 84364mm): approximately 60 degrees Celsius for 700A sustained for 10 minutes, and approximately 55 degrees Celsius for 800A sustained for 7 minutes, which are far lower than the temperature rises of other types of sensors.
Third: [Cost Advantage]
Due to the adoption of open-loop Hall technology, the Innosense solution has significant cost advantages compared to other high-precision sensors.
Fourth: [Functional Safety]
The Innosense sensor can achieve functional safety ASIL-D, and is more reliable and cost-effective due to its simple architectural design.
In summary, Innosense's innovative high-precision Hall current sensor solution can effectively overcome multiple challenges such as small current detection, temperature rise, cost, and functional safety in sentinel mode.
03 Who is Innosense?
Innosense was founded in 2021, with its headquarters located in Jiading, Shanghai, and a research and development center in Lyon, France, focusing on cutting-edge technology research. Its core team comes from internationally renowned sensor, OEM, Tier 1, and electrical system enterprises, and its products cover current and position sensors.
Innosense aims to become a world-class supplier of sensor solutions. Currently, it has deployed in East China, North China, South China, Central China, and the European market domestically, and will further expand its coverage in the future.
Innosense has been recognized as a high-tech enterprise and has obtained IATF16949 system certification, as well as ISO14001 and ISO45001 certifications, among others, and is currently undergoing functional safety system certification.
The company boasts strong R&D capabilities, with a world-class core R&D team, holding over 30 patents and multiple software copyrights and invention patents. To date, it has mass-produced nearly ten product series, with a cumulative vehicle installation of over 300,000 units.
Meanwhile, Innosense's high-precision current sensor products have been recognized by several well-known domestic and international customers.
With the continuous expansion of the new energy vehicle market and the continuous updating of battery technology, the demand for high-precision current sensors is also growing. Innosense states that it will continue to increase investment in technology research and development, constantly innovate and make breakthroughs, contributing more to the development of global new energy vehicles and battery technology, and creating greater value for customers.
