H1102NL Current transformer is a kind of sensor used to measure current, which is often used in current measurement, protection and control applications in power system. The secondary current selection and accuracy of current transformer shall be determined according to the specific application situation.
1、 Selection of secondary current
The selection of secondary current of current transformer mainly considers the following factors:
1. Current transformation ratio: the ratio between primary current and secondary current of current transformer, usually expressed by transformation ratio. When selecting the secondary current, first determine the transformation ratio according to the actual measured primary current range, and then calculate the corresponding secondary current according to the transformation ratio. For example, if the primary current range is 0-1000A and the transformation ratio is 1000:5, the secondary current should be 0-5A.
2. Rated current of the instrument: the rated current of the instrument connected at the output end of the current transformer shall also be considered when selecting the secondary current. Generally speaking, the rated current of the instrument shall be less than or equal to the secondary current of the current transformer to ensure the normal operation of the instrument and improve the accuracy of measurement.
3. System safety: the safety of the system shall be considered when selecting the secondary current. In general, the greater the secondary current, the better the system security, because under high secondary current, the system is more sensitive and can detect faults better.
Based on the above considerations, different secondary currents can be selected according to different applications. Generally speaking, 1A secondary current can be selected for low-voltage and low-power applications, while 5A secondary current can be selected for medium voltage and high-power applications.
2、 Application occasions with different precision
The accuracy of current transformer refers to the error between its output current and actual current. According to different error ranges, the accuracy of current transformers can be divided into several levels, such as 0.5, 1, 3, etc. The selection of current transformers with different accuracy shall be determined according to the specific application situation.
1. High precision occasions: In some occasions with high requirements for current measurement, such as electric energy metering, power load monitoring, etc., high-precision current transformers need to be selected to ensure the accuracy of measurement. Generally speaking, Class 0.5 or Class 1 current transformers can meet the requirements of these occasions.
2. Where the accuracy requirement is relatively low: In some occasions where the current measurement requirement is relatively low, such as the protection and control of power equipment, the current transformer with lower accuracy can be selected to reduce the cost. Generally speaking, Class 3 current transformers are enough to meet the requirements of these occasions.
It should be noted that the actual application environment, such as temperature, humidity and other factors, should also be taken into account when selecting the accuracy of current transformers to ensure that they can work normally in the actual working environment and maintain high measurement accuracy.
To sum up, the secondary current selection and accuracy of current transformer shall be determined according to the specific application situation. The reasonable selection of secondary current and accuracy can meet the requirements of current measurement in different applications and improve the security and reliability of power system.
