"电涌特性" can be translated as "surge characteristics," and "喘振特性" (referring to the characteristic of surge or pulsation in machinery, especially in compressors) can be translated as "surge (or pulsation) characteristics" as well, though in some technical contexts, it might be more specifically termed as "compressor surge characteristics" when referring to machinery. Combining them, you could say:
"Surge characteristics and compressor surge (or pulsation) characteristics"
However, if the context is clear and you're simply referring to two types of surge-related behaviors without needing to distinguish between electrical and mechanical surges in great detail, you might simplify it to:
"Surge and pulsation (or surge) characteristics"
The choice of "pulsation" or repeating "surge" depends on the nuance you want to convey and the audience's familiarity with the terms. In many technical discussions, "surge" is sufficient to cover both electrical and mechanical surges, especially when the context makes it clear which type is being discussed.