Highly accelerated life test of 1.5kW class Low DC-DC converters for hybrid electric vehicles

This paper confirms the operational limit and breakdown threshold of low voltage dc-dc converters (LDCs), which are a key component of electric vehicles (xEVs) systems, proposes a highly accelerated life test (HALT) method for predicting the operational lifetime of LDC, and analyzes the experimental results. HALT is the most effective test process for predicting the operational limit and breakdown threshold of products. Especially, for vehicle component HALT, the operational environment and product characteristics must be understood and the test method should be designed. Although LDC is a brand new key component for xEVs, designing the rational test process remains difficult since there are only a few research cases. In this paper, HALT has been implemented to take account of the electrical performance and operational characteristics under the real development process of an LDC. The prototypes are 1.5 kW class LDCs which are applied to the HEV in mass production, and the test has been carried out considering the condition of real vehicle installation and operational conditions. Through the test results, the upper operating limit (UOL) and lower operating limit (LOL) are identified, and the electrical mechanism which generates the operational limit is analyzed.