When the “double carbon” target drives the comprehensive green transformation of public transportation system, and when the new energy subsidy policy continues to deepen, the wave of technological innovation in Dongfeng Special Vehicle (Shiyan) Bus Co., Ltd.(Dongfeng SVB) with its profound car-making background and forward-looking strategic vision, has built up a strong technical barrier on the pure electric bus track, and is leading the industry in the direction of more efficient, more reliable, and more intelligent metamorphosis.
I.Power heart: high safety, long-rangebattery system
The surging power carried by Dongfeng Special SVB comes from its finely crafted three electric cores. The battery system adopts the top lithium iron phosphate (LFP) batteries of Ningde Times, BYD and other leading enterprises, which are mature, stable and safe. The battery pack adopts a combination of system protection: a high-strength aluminum alloy box with IP68+IP6K9K top protection performance; integration of high-voltage fast power-down function after collision; introduction of active spray thermal suppression system to control thermal runaway; and BMS battery management system with five levels of safety mechanisms to ensure worry-free operation. Flagship models (e.g., EQ6603LTBEV) are equipped with high-capacity battery packs, with a working range of over 340 kilometers for city buses, which can easily meet the needs of long-distance operation.
Intelligent temperature control technology ensures that the battery can perform in a wide temperature range from -30℃ to 45℃. Intelligent thermal management system adjusts the cooling/heating strategy in real time according to the external temperature and battery status, ensuring that the mileage does not shrink in the cold winter in the north (the measured attenuation of -20℃ is less than 28%). Ultra-strong energy management logic significantly extends battery life, with 80% capacity retention rate up to 4,000 cycles or more.
II. The Soul of the Drive: High-efficiency Flat-wire Motors and Precise Controls
The drive assembly adopts industry-leading flat-wire wound permanent magnet synchronous motors, with a peak efficiency of 97.5%, which is the highest in the industry. This technology not only realizes a jump in power density through a higher slot filling rate (e.g., 360kW high-power motor supporting high-speed intercity operation), but also guarantees the vehicle’s starting acceleration advantage with its compact structure and high torque output (3200N-m peak). The oil-cooling technology solves the problem of heat dissipation of the motor at high loads, and ensures continuous and stable power output during hill climbing and full load.
The motor controller (MCU) is equipped with Dongfeng’s self-developed vector control algorithm. The drive strategy can adjust the torque output according to real-time road conditions and loads, improving the energy economy by more than 7%. The energy recovery efficiency of electric braking is raised to 90%, and the battery can be recharged with considerable energy after one braking. The entire vehicle control system opens up the intelligent collaboration between the VCU, BMS and MCU to form a closed-loop response network, ensuring the precise matching and smooth output of the drive system, so that passengers can hardly feel any acceleration stutter.
III. Lightweight stance: composite materials enable efficient energy performance
Lightweight is the core strategy to realize low energy consumption. Dongfeng SVB applies an all-aluminum frame and high-strength steel hybrid body skeleton to achieve a perfect balance between crash safety and weight control. Large areas of the body are covered with glass fiber reinforced composite materials (such as SMC), which are corrosion-resistant, low-density and have flexible mold characteristics. The exterior parts (such as bumpers) are also made of lightweight PP-LGF material, which reduces the weight of the whole vehicle by more than 18% compared with traditional buses.
Structural topology optimization technology combined with CAE-assisted simulation has streamlined the bodywork while ensuring structural strength at key locations. The aerodynamic design is also excellent: the streamlined design of the entire vehicle is matched with an active grille, and the wind resistance coefficient is as low as 0.36. Through the comprehensive optimization of the trinity of lightweight, drag reduction and high efficiency, the electric power consumption of the entire vehicle is as low as 0.6-0.7 kWh/km (for the 12-meter model), which greatly reduces the cost of long-term electric power expenditure of the operator.
IV.Intelligent Control System: All-weather Safety and Intelligent Advancement
In the face of severe climatic conditions such as high temperature and cold, Dongfeng’s exclusive vehicle thermal management matrix has super adaptability. Equipped with a dual-channel air conditioning frequency conversion compressor system, energy consumption is optimized by 25% year-on-year. Multi-area heat pump technology for battery, cockpit and other areas is used for coordinated heating/cooling, and waste heat recycling is realized. Some models use phase change material (PCM) to maintain a constant temperature of the battery, realizing zero degradation of power performance under extreme temperatures.
ADAS driver assistance system reinforces the line of defense for safe operation: 360° panoramic image is equipped in the whole series to eliminate visual dead angles; FCW and AEB systems reduce the risk of collision at intersections; and intelligent hill assist makes parking easier. The chassis is equipped with the combination of EBS electronic brake + ECAS electronically controlled suspension, which improves the level of roll control in curved driving, guarantees the smoothness and safety of high-speed driving, and establishes a new safety benchmark for public transportation.
V.Conclusion
Dongfeng SVB continuously refreshes the industry benchmark with reliable three electric cornerstones, strong environmental adaptability and continuous intelligent advancement. It is not only a passenger-carrying tool, but also a mobile platform integrating China’s top electric drive technology, lightweight engineering and intelligent Internet technology. With the deep satisfaction of the three core demands of safety, efficiency and intelligence, Dongfeng Special Truck is driving the green transformation of China’s public transportation towards a more far-reaching “zero-emission” blueprint. Dongfeng has found the optimal path to break the ice in this “long slope and thick snow” belonging to new energy buses.
