Intelligentization For Vehicle Electrical Power Supply System

With the development of automotive technology, the power consumption of vehicle electrical system increases continuously, and same does the complex of electrical wiring connections inside. In traditional vehicle electrical system, a power consumer always has to be wired in series with both its switch/key/relay and power supply, which results in overabundance of wiring harness in the vehicle and extreme difficult in protecting all the power lines with a simple solution. In recent years, with the development of intelligentization of vehicle electrical system, the constraints between power consumers and their switches/keys/relaysare getting released, which makes it possible for zoning the consumers and supplying electrical power to zones instead of individuals. In Vehicle Smart Electrical/Electronic Device System (SEED System), all electrical appliances are intelligentized, and their constraints with the switches/keys/relays and any other related appliances are completely released. Constraints arecarried out by the central coordinating control mechanism, and all appliances are divided into several zones. SEED system requires electrical power supply to these zones, and an intelligent electrical power supply sub-system is demanded. Hence, this paper studies the intelligentization of vehicle electrical power supply system (VEPSS) in SEED system.VEPSS supplies 2 classified electrical powers to all appliances in the vehicle: load power (LP) and controller power (CP). LP supplies power to all traditional appliances which consume big current and require lower power quality, while CP supplies power to all ECUs and controller circuits which consume low current but require high power quality. LP lines and CP lines are designed in VEPSS based on the requirements of appliance zones of SEED system, and all lines are intelligentized.For intelligentization of LP, firstly the LP power lines need switch function to shut down all possible appliances to keep quiescent current as low as possible; then the current flowing through LP lines is measured in order to provide SEED system with detailed information of VEPSS and to achieve over-current protection for LP lines as well; lastly, LP line safety protection is ensured by both short-circuit instant shutting down design and over-current protection for dynamic load based on central coordination mechanism. Additionally, all battery performance parameters including current, voltage and temperature are constantly monitored and used later as key data for battery over-discharge protection.For intelligentization of CP, firstly the CP power lines supply 2 switchable lines to SEED system and provide all ECUs and controller circuits with stable power isolated from LP, which preventspotential pollution from LP; then the safety of both LP lines is ensured by over-current protection for sustained load based on central coordination mechanism.The excitation coil of power generator is intellgentized as a non-power SEED. Its power supply is controlled by bus messages; its over-current failure is detected continuously and instantly protected; and the generating status is also monitored constantly. The correct functioning of power generator is therefore ensured, and its generating status is updated repeatedly to SEED system.All SEEDs in VEPSS are designed, made and assembled. All functions of VEPSS are verified on a bus with SEED system.