Sensors used in hydrogen fuel cell vehicles mainly include hydrogen sensors, pressure sensors, and temperature sensors. Each type of sensor has a different function and varying levels of technical difficulty. Currently, the hydrogen and pressure sensors used in domestic hydrogen fuel cell vehicles are mainly imported products. Hydrogen sensors are primarily from Figaro (Japan), while pressure sensors are mainly from Huba Control (Switzerland) and Sensata (USA). Domestic products have a relatively high market share for temperature sensors.
There are many reasons why the hydrogen fuel cell vehicle sensor market is highly dependent on imports. The most critical factor is the small market demand, which leads to a lack of motivation for companies to conduct research and development, and insufficient testing of domestically developed products. However, as the scale of hydrogen fuel cell vehicles in China expands, some domestic companies have begun to recognize the business opportunities and have specifically launched projects to accelerate the research and development of hydrogen fuel cell vehicle sensors.
A hydrogen fuel cell system company, representing the application side, stated: "The opportunities for domestically produced sensors are enormous. However, automotive sensors need to be well-matched in terms of engineering. We suggest that sensor manufacturers better understand the needs of users and the requirements of automotive standards. As long as domestically produced products pass the tests, they will be very competitive. For example, the price of domestically produced pressure sensors is less than half that of imported ones."
The following mainly introduces the hydrogen sensor for hydrogen fuel cell vehicles.
A hydrogen sensor includes a sensitive probe, a circuit board, an outer housing, and related structural components; the sensor's interface with the outside world is mainly a communication interface. These subsystems are organically combined to form a hydrogen sensor component.
The primary function of installing a hydrogen sensor is to ensure the safe operation of hydrogen fuel cell vehicles. As is well known, hydrogen is a flammable and explosive gas. For hydrogen fuel cell vehicles, the hydrogen sensor can detect when the hydrogen concentration exceeds a safe range and promptly send an alarm signal to the vehicle. The vehicle system will then immediately implement corresponding power-off safety protection measures to prevent accidents.
Furthermore, hydrogen sensors can be used not only to monitor hydrogen leaks in the tank and fuel cell stack, but also to detect the hydrogen concentration in exhaust gases. Hydrogen fuel cell vehicles can then use this monitoring information to analyze the stack's performance and reaction rate in real time, thereby adjusting relevant input parameters or data configurations to achieve safe and efficient vehicle operation.
An executive at a fuel cell system company said, "The national standard has requirements for the hydrogen safety of hydrogen fuel cell vehicles. The number of hydrogen sensors a vehicle needs must be considered in conjunction with spatial layout, ventilation, and safety. Generally speaking, at least one is needed in the engine, hydrogen storage tank, and driver's cabin (inside the vehicle), and the exhaust system will also require one. Our internal standard is at least five."
It's worth noting that hydrogen sensors come in many specifications and have varying measurement ranges. Different fuel cell vehicle models, and even different locations within the same model, have different requirements for hydrogen sensors. Those requiring high temperature and humidity resistance, as well as high precision, will be more expensive. Considering both meeting vehicle requirements and reducing costs, users generally choose a comprehensive hydrogen sensor solution.
According to our research, most hydrogen sensors used in domestic hydrogen fuel cell vehicles can currently be from the Japanese brand Figaro.
From a technical perspective, sensors are not new, but automotive hydrogen sensors differ from consumer sensors. Their operating conditions are extremely complex, requiring them to withstand harsher high and low temperatures along with the vehicle, while also resisting external forces (such as vibration and impact). The development of automotive hydrogen sensor products must meet the basic requirements and processes of automotive-grade product development, starting with system requirements description and analysis, iterating step-by-step through design, analysis, verification, and finally vehicle testing to ensure the product's comprehensiveness, reliability, and safety.
The development of gas sensors in China is currently uneven, and the performance of consumer-grade gas sensors is insufficient to meet the requirements of complex automotive operating conditions. Developing automotive-grade hydrogen sensors is a significant challenge for most sensor manufacturers. Besides technical reasons, a more critical factor is the relatively small market demand and low unit price, which discourages companies from investing substantial resources in developing automotive-grade hydrogen sensors. Furthermore, downstream users are unwilling to spend more time validating new products.
Currently, very few manufacturers worldwide have specifically launched research and development projects for hydrogen sensors used in hydrogen fuel cell vehicles.
"We will choose those that are widely used and have been verified overseas. From a system perspective, a single system costs hundreds of thousands of yuan, while the price of several hydrogen sensors combined is less than 10,000 yuan. We don't have that much time to verify them. We just need to consider that the range, accuracy, and reliability meet the requirements." The head of a fuel cell system integrator said frankly that it is normal logic to prioritize stability and reliability in the early stages and then gradually replace them with domestic products.
However, he also stated that when there is a high demand for hydrogen sensors, domestic production should still be supported.
The TGS2615-E00 is a semiconductor-based gas sensor developed by FIGARO in Japan. It features fast response, low power consumption, and small size. The TGS2615-E00 incorporates a filter layer to eliminate interference from gases such as alcohol, exhibiting extremely high selectivity for hydrogen. It is highly suitable for detecting hydrogen leaks in hydrogen fuel cell systems. The TGS6814 is a catalytic combustion gas sensor, an upgraded version of the TGS6812. It can detect methane gas at the 100% LEL (lower explosive limit) and also H2. This sensor not only boasts excellent durability and fast response, but also features linear output and high output stability. It can also be used to detect hydrogen leaks in hydrogen fuel cell systems.
