Background Linear Transformer Driver (LTD) are among the most critical and complex systems in Z-pinch device, and reliability assessment is a central issue in the demonstration of device design schemes.

Purpose This study aims to establish a probabilistic model for switch self-breakdown and capacitor failure based on the basic components of the power source, and to propose a hierarchical analysis method for system-level reliability quantification.

Methods Probability models for switch self-breakdown and capacitor failure were developed based on fundamental components such as switches and capacitors. A top-down hierarchical analysis approach was adopted to construct reliability models for the brick layer, LTD cavity layer, and LTD branch layer, along with a fault-domain boundary calculation method. System-level reliability was quantified using Monte Carlo simulations based on performance-margin reliability theory.

Results The results indicate that when the allowable number of faults in both the LTD cavity layer and the branch layer is greater than one—and neglecting special cases such as simultaneous nanosecond-scale switch failures (extremely low probability) and multiple adjacent cavity failures—the system reliability does not exceed the product of the reliability of the IVA secondary and the fault-isolation switch. A single unintended switch discharge coupling voltage nearly doubles the failure probability of other switches within the same cavity, while its impact on switches in other cavities is on the order of 10⁻⁴ and on capacitors about 10⁻⁶. This coupling effect can be ignored in system reliability calculations only when the allowable number of faults in both the cavity and branch layers exceeds one. As component reliability improves, enhancing switch reliability below 0.9996 significantly affects system reliability, whereas improving capacitor reliability only noticeably influences the system when switch reliability is relatively low.

Conclusions The proposed hierarchical reliability modeling and Monte Carlo simulation approach provides a systematic framework for evaluating ultra-large-scale LTD systems in Z-pinch devices. The findings highlight the conditional negligible effects of coupling voltages and offer guidance for prioritizing component reliability improvements in engineering design.