Such transformers have the main function of converting any current value to the most convenient values for measuring, providing power to disconnect devices, and relay windings. Each current transformer has individual parameters and technical characteristics that determine the scope of these devices. ), duty cycle, etc., are important specifications that should be considered. They are mounted in high voltage circuits into which the measurement instruments can not be directly connected. With a certain number of turns, the voltage from the external network is supplied to the primary power winding and overcomes its total resistance. Would you like to write for us? Inclusion in the primary winding circuit is performed in series with current lead. Dimensional constraints (like width, length, thickness, etc. All products with ANY of the selected attributes will be returned as matches. The current transformer error also increases with its rise. This is the full-required range of ambient operating temperature. As a rule, one of the ends of the secondary winding is grounded, so the winding and earth potentials will be approximately equivalent. Your email address will not be published. But if you take three transformers for the same overall power with magnetic cores of different shapes, it turns […]. A “protection” current transformer (CT) must saturate sufficiently high to allow a relatively accurate measurement of the fault current by the protection whose operating threshold can be very high. The alternating current flowing in the primary winding generates a magnetic field which induces current flow in the secondary winding. The Current Transformer ( C.T. The history of industrial design dates back to the 1900s when the industrial revolution had just begun. The primary and secondary windings have a certain proportion between the currents. Bar current transformers are toroidal transformers with a bus bar permanently inserted through the window of the toroid. Required fields are marked *. Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. Why do earthquakes occur? There would appear to be no difference, because the main thing is the power the transformer is able to convert. This category only includes cookies that ensures basic functionalities and security features of the website. Evaluation of parameters, like number of primary turns, current ratio, secondary current value at specific primary current value. In electrical engineering, quantities with large values need to be calculated relatively frequently. Current Transformer is fundamentally a transformer, it translates the current from the Pecondary side, rimary to the S inversely proportional to the turns so as to maintain the relationship, IP = n IS where, n is the turns ratio of turns between the secondary and primary winding. Electrical Steel: Essential Things You Need to Know, Toroidal Transformers – Device, Application and Technical Features, What is Core Loss in transformer? Accuracy is another specification which is expressed as a maximum percentage or maximum absolute change over the complete primary current range. What is Toroidal Core? Measuring transformers forward the information received to related measuring instruments. A transformer is a device that transmits electricity from one circuit to another through inductively coupled transformer coils. are some other design specifications. ... whose value can be calculated after alternatively measuring the desired output voltage with respect to the primary current. Current transformers are thus expected to have an Accuracy Limit Factor (ALF) that is usually fairly high. Current transformers are used to solve this problem, the purpose and operating principle of which allow some measurements to be carried out. A current transformer is an integral part of electrical engineering, which when used with a potential transformer, is known as an instrument transformer. The primary of the transformer is inserted in series with the conductor that is being monitored. The load should be of low resistance and the core’s design rating should be more than the voltage time integral area, else the core may enter into saturation mode at the end of each cycle, and will affect the transformer’s efficiency. With Calculation and Formula. ), type of waveform (sine wave, square wave, triangular, etc. Use of this website signifies your agreement to our Terms of Use. A current transformer has a primary winding, a core and a secondary winding, although some transformers, including current transformers, use an air core. The reliability would ensure that the transformer works normally.