Quality control, commissioning and diagnostic tests on insulation systems of electrical apparatus are necessary to reduce the failure risk under operation, eliminate infant mortality failures and reduce the impact of ageing on insulation system reliability. This study tries to establish a path which, based on the statistical–phenomenological modelling of the hazard rate, or bathtub curve, drives in the choice of test overvoltage and procedures. The choice of the test voltage and its waveform should be made carefully to improve reliability (reduce failure hazard) in any section of the bathtub curve. This may require, however, different choices depending on the section which corresponds to the planned test. For example, large overvoltages could be acceptable to remove the infant mortality to ensure the highest reliability of newly commissioned apparatus, but they can incept highly energetic, and, thus, fast degradation mechanisms on apparatus operating on the field for a period of time, that can worsen, rather than improving, the insulation system reliability. Resorting to partial discharge measurement during any overvoltage test seems to be the optimal solution to find the most appropriate overvoltage for any type of testing need, leveraging the Latin concept that ‘in medio stat virtus’.

必须对电气设备的绝缘系统进行质量控制，调试和诊断测试，以降低运行中的故障风险，消除婴儿死亡率故障并减少老化对绝缘系统可靠性的影响。这项研究试图根据危险率或浴盆曲线的统计学现象学模型建立一条路径，以驱动测试过电压和程序的选择。应该仔细选择测试电压及其波形，以提高浴缸曲线任何部分的可靠性（减少故障危险）。但是，根据与计划的测试相对应的部分，可能需要不同的选择。例如，可以接受大的过电压来消除婴儿死亡率，以确保新投产的设备具有最高的可靠性，但是它们可以承受很高的能量，因此，在现场运行一段时间的设备上的快速降级机制会使情况恶化，而不是提高绝缘系统的可靠性。在拉丁文中，“在中等电压状态下”，利用任何过电压测试中的局部放电测量似乎是找到适合任何类型测试需求的最合适过电压的最佳解决方案。