The combined DC-DC power supply is widely used in communication, aerospace and other fields because of its low power consumption, high efficiency, small volume, high reliability, modularization and so on. As the core component of power electronic system, its reliability prediction research has far-reaching practical significance. In this paper, the engineering application of reliability prediction is studied based on a combined DC-DC power supply of 17.2 kW. The prediction of the basic reliability based on “life profile” and the mission reliability based on “mission-profile” are studied. The block diagrams of basic reliability and mission reliability are established, respectively. The MTBF is 31,699 h, which is more than three times of the required value of the power supply. The reliability of the power supply for 1 h can reach 99.999%. The reliability prediction of the two aspects has practical guiding significance for the reliability distribution and reliability growth of the project, and can also be used as reference for the reliability work of other projects.

DC-DC组合电源由于其低功耗，高效率，小体积，高可靠性，模块化等优点而被广泛应用于通信，航空航天等领域。作为电力电子系统的核心组成部分，其可靠性预测研究具有深远的现实意义。本文研究了基于17.2 kW组合DC-DC电源的可靠性预测的工程应用。研究了基于“生命特征”的基本可靠性的预测和基于“任务特征”的任务可靠性。分别建立了基本可靠性和任务可靠性的框图。MTBF为31,699 h，是电源要求值的三倍以上。1小时的电源可靠性可以达到99.999％。