A Review of Key Technologies and Development of Low-Voltage Power Supply Systems for Electric Vehicles

Abstract

As a fundamental core unit of the electric vehicle (EV) electrical architecture, the low-voltage (LV) power supply system undertakes the core functions of supplying power to all LV electrical devices, providing vehicle-level electrical safety protection, and enabling energy coupling and coordination between high-voltage and low-voltage electrical systems. Its operational stability, structural integration level, and safety protection capability directly affect the reliability and driving safety of the entire vehicle. With the rapid proliferation of automotive electrification and onboard intelligent control systems, the vehicle electrical architecture is gradually upgrading toward a domain-centralized integration model. The shortcomings of the traditional 12 V LV power supply system have become increasingly prominent, including limited power supply capacity, insufficient adaptability to high-power loads, low hardware integration, and weak fault redundancy protection, making it difficult to support the stable operation of new high-power devices such as intelligent driving systems, onboard intelligent terminals, and multi-domain electronic control modules. Against this industrial backdrop, this paper takes the EV LV power supply technology system as its research subject and systematically reviews the technological development of LV power supply systems from four core dimensions: architectural evolution, core component technology characteristics, fault diagnosis and protection mechanisms, and industry technology trends. By comparing the technical features and practical application scenarios of different electrical architectures, this paper analyzes the technical bottlenecks and optimization challenges of core components such as DC-DC converters, LV energy storage devices, and intelligent power distribution modules, and summarizes fault generation mechanisms, safety protection schemes, and electromagnetic compatibility optimization methods under complex onboard operating conditions. Combining existing domestic and international research achievements, this paper forecasts the future technological evolution of LV power supply systems.