How to select and match current transformers?

    Current transformers are vital components in power supply systems. They serve as devices for detecting current and can be paired with various instruments and equipment to monitor different aspects such as current, power, energy, power factor, relay protection for secondary circuits, and motor overload protection in the circuit.

    In terms of voltage level, current transformers can be categorized into high voltage and low voltage types.

    In terms of structure, they can be classified as enclosed or open current transformers.

    Installation methods also determine their classification, with busbar type and enclosed type being the two main categories.

    Accuracy is another factor for classification, with levels such as 0.5, 0.5S, 0.2, 0.2S, 0.1, and 0.01.

    Their functions further divide them into line current transformers and zero sequence transformers.

    Mutual inductance ratio is yet another criterion for categorization, with secondary side currents of 1A and 5A.

    Transformers at the 0.5 and 0.5S levels are commonly used for motor or line detection, as well as for current monitoring and sampling. They can also be utilized for energy metering.

    Transformers at the 0.2 and 0.2S levels are typically employed for