Fuel cell system

Fuel cell systems are fuel cell engines in the general sense, consists of integrated stacks, hydrogen and oxygen supply systems, hydrothermal management systems, power exchange systems, and control systems. The stack is a credible component of the entire engine. The basic structure consists of electrodes, electrolyte diaphragms and current collectors (also known as bipolar plates).

During operation: hydrogen and oxygen enter the stack through the pressure regulator and humidifier respectively, and the electrochemical reaction generates DC current, which is then supplied to the vehicle through dedicated DC/DC voltage regulation and conversion. Then, the water produced by the reaction is discharged into the air through the air, and the unreacted hydrogen is re-entered into the stack through the circulation device, and can be directly discharged into the air in the open space.

At present, the hydrogen fuel cell passenger car of CRRC TIMES ELECTRIC VEHICLE CO., LTD. uses a third-generation fuel cell engine with a highly integrated modular design, resulting in a 20% smaller volume. Thanks to the continuous upgrading of fuel cell engines, CRRC electric hydrogen fuel cell bus has successfully realized -30 °C low temperature start, -40 °C low temperature storage and automatic shutdown, 10-15mins hydrogen filling, 400km or more cruising range, 15000h stack life and other technical breakthroughs, which greatly improve the vehicle performance.

Power battery system

The power battery is used as an auxiliary power source for fuel cell bus, mainly in the conditions of bus start, acceleration, and climbing. When the required driving power is greater than the power that the fuel cell can provide, the power battery releases the stored electrical energy, thereby reducing the peak power demand of the fuel cell, so that the fuel cell is in a stable working state; when the passenger car is under idle speed, low speed or deceleration, it stores the surplus energy of the power system, or absorbs the stored braking energy when the brake is applied, thereby improving the energy efficiency of the entire power system. The hydrogen fuel cell bus of CRRC TIMES ELECTRIC VEHICLE CO., LTD. adopt lithium manganate power battery, which has light weight, long service life, low temperature energy consumption and high safety.

Other systems

The hydrogen fuel cell bus system also includes a series of electrical and control systems, etc., covering vehicle braking, steering, air conditioning, vehicle controllers, GPS, etc.

Hydrogen safety technology

The hydrogen fuel cell bus of CRRC TIMES ELECTRIC VEHICLE CO., LTD. reasonably arranges the roof hydrogen tank, the car, and the fuel cell storage bin. The hydrogen storage bottle adopts an open design and cannot form a confined space, effectively avoiding the proportion of hydrogen co-firing explosion. Gas is evacuated in time; 3-5 safety alarms are installed in the hydrogen system, and once leaked, an alarm will be issued to develop a high-voltage (35MPa) hydrogen system design specification for over-voltage, over-temperature prevention, over-current prevention, and anti-accumulation; Test technology of extreme conditions, such as gunshot and fire burning, is developing, in order to deal with extreme conditions. Real-time concentration monitoring are applied on multi-point of finished vehicle to achieve safety warning and grading control of vehicle hydrogen system.

Electric safety technology

The hydrogen fuel cell passenger buses of CRRC TIMES ELECTRIC VEHICLE CO., LTD. realizes the safety warning and real-time control of the vehicle electrical network through accurate monitoring and online analysis of parameters such as voltage, current, temperature and insulation resistance. It includes vehicle electric safety multiple early warning protection system, vehicle electrical collision monitoring system, thermal imaging test of battery and motor temperature distribution, vehicle online insulation monitoring system and vehicle electrical fire monitoring system.

Collision safety technology

CRRC TIMES ELECTRIC VEHICLE CO., LTD. has developed the integrated hydrogen-electricity-collision multi-coupling safety integrated management and interlock control technology, successfully implemented the international first passenger car hydrogen-electric system pressure collision test, effectively avoiding the installation structure failure caused by collision