This article focuses on practical deployment: how CTs feed protective relays, how to select and size CTs for different protection schemes, common installation and testing practices, and how modern sensor technologies change protection design. As you should already know, current transformers are used for metering and relay protection purposes. Overcurrent Protection Protects against overloads and external short circuit faults: 2. Differential Protection (87) The most sensitive protection for internal transformer faults: Note: Differential. Introduction Current Transformers (CTs) are used in power systems to measure current levels and provide accurate readings for various purposes, including billing, monitoring, and control.
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