Testability Study of Medium Voltage DC Switchboard Based on Testability Index

Medium voltage DC switchboard is an important part of vessel integrated power system, which directly affects the usability and life cycle cost of the system. At present, there is little research on the testability of medium voltage DC switchboard in China, which affects the full play of its role to a certain extent. Firstly, the testability design of a ship's medium voltage DC switchboard is analyzed. Based on the D matrix-multi-signal flow graph theory, the testability model is established, the fault detection rate and fault isolation rate are calculated, and the problem of low testability index is pointed out. In order to improve the level of testability design, the testability analysis of non-detectable faults of switchboard is carried out at the present stage. The test points are designed based on the characteristic parameters of components when faults occur, and the test set selection is optimized by the theory of test point optimization. After the optimized testability model is established. Through testability prediction, the results show that all the key non-detectable faults of existing switchboard can be detected and isolated; testability indicators are greatly improved, which verifies the feasibility of testability design. This paper provides a basis and reference for improving the testability design level of the existing medium voltage DC switchboard.