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Integrated Systems And Specialized Vehicles
Integrated Systems And Specialized Vehicles
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Industrial Intelligence
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Intelligent Transportation
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Securing the "Lifeline" of Low-Voltage Power Supply: Hirain Technologies Wins Another Nomination for Its Intelligent Power Distribution Unit
Release time:
2026-09-14 18:00
The vehicle's low-voltage power network is the most inconspicuous piece of infrastructure on board — yet every controller and actuator in the body, cockpit, and chassis depends on it for stable power. And as the industry moves toward by-wire vehicle systems, the demands placed on this network are reaching entirely new heights. Once steering and braking are driven by electrical signals, power supply reliability becomes directly tied to driving safety — GB 21670-2025, GB 17675-2025, and UN R13-H have accordingly introduced stricter power supply and redundancy requirements for braking, steering, and other safety-critical systems. Combined with the rollout of advanced driver assistance and growing vehicle electrical loads, low-voltage power demand is climbing in parallel: Level 4 autonomous driving will require 5–6 kW of low-voltage power. Low-voltage power supply is evolving from a simple "power-on guarantee" into the "lifeline" of safe operation for intelligent electric vehicles.
Recently, Hirain's Intelligent Power Distribution Unit (E-Fuse Unit, EFU) secured another new nomination and will be featured on a premium new energy vehicle model. As early as 2024, Hirain's intelligent power distribution unit for complete vehicles had already entered mass production, with cumulative deliveries reaching 400,000 units.
What enables the EFU to guarantee highly reliable low-voltage power supply? The answer lies in its three integrated core technologies: grid isolation, intelligent power distribution, and voltage conversion.
▎Grid Isolator: "Dual Protection" for the Low-Voltage Power Network
A conventional low-voltage network is a single-source power system, where a fault at one point can cascade throughout the entire vehicle. The grid isolator divides the network into A/B redundant power grids: under normal conditions, the two grids supply power in an interconnected configuration; in the event of a fault on one side, disconnection occurs within microseconds, containing the fault to that side alone while the other grid remains unaffected — a critical element for achieving functional safety compliance. Hirain offers multiple isolator solutions to meet the redundancy requirements of both parallel and series grid architectures, with functional safety certified up to ASIL B / ASIL D and overcurrent capacity of up to 200 A.
▎E-Fuse: The "Intelligent" Evolution of the Fuse
Traditional fuses provide one-time melting protection — they must be replaced after a fault and offer no self-diagnostic capability. The E-Fuse replaces conventional fuses with semiconductor devices, integrating short-to-ground protection, I²t protection, overtemperature protection, and high-precision current sensing, delivering precise protection within microseconds when the wiring harness or downstream loads behave abnormally. Protection thresholds are programmable; once a fault is cleared, the E-Fuse recovers automatically with no fuse replacement required, and it supports current feedback and remote diagnostics. The solution covers power distribution needs from 0.5 A to 150 A, features Hirain's self-developed protection algorithms, and meets ASIL B functional safety requirements — serving diverse power demands at a more competitive cost.
▎48 V / 12 V DC-DC Converter: "Lightening the Load" for High-Power Demands
To meet the high low-voltage power demands of Level 4 autonomous driving, a 12 V system must carry large currents through thicker wiring — increasing harness weight and thermal losses, which has become a real burden on vehicle range. The industry is therefore trending toward a 48 V upgrade. Hirain's 48 V / 12 V DC-DC converters cover a power range of 500 W to 3,600 W, with efficiency of up to 98% and a choice of fixed-ratio or fixed-voltage configurations, solving the power supply challenge of coexisting 12 V and 48 V electrical loads during the transition period.
Built on the combination of these three core technologies, Hirain has developed a platform-based family of 12 V and 48 V intelligent power distribution units: the 12 V version supports dual power inputs with an integrated isolator, while the 48 V version incorporates a built-in 48 V / 12 V DC-DC converter. Development results can be reused across vehicle platforms, significantly shortening adaptation cycles.
Looking ahead, Hirain will continue to uphold its philosophy of "Value Innovation, Customer Service," deepening its expertise in intelligent low-voltage power distribution. With technology solutions proven in mass production at scale, Hirain will lay a solid low-voltage power supply foundation for by-wire vehicle systems, advanced driver assistance, and the evolution of E/E architecture — making every watt of power controllable, diagnosable, and trustworthy.