Calculation of inrush current in any terminal with depended parameters such as damping time, pick and effective current in any switching angle, etc. What is an interposing current transformer, and why is it. Interposing current transformer is defined as the one in which there is a piece of equipment with a ratio whose selection can be done by the user in order to do the achievement of the balance. They are fully insulated from the high operating voltage of the system and are usually bolted to the current carrying device. Typical voltage and current reference direction for a power transformer power transformer differential protection scheme with interposing cts. Ctdim current and voltage transformer selection, dimensioning. Some particular relays can even compensate online for ltc movement 3, 4 and.
Current transformer basics and the current transformer. Interposing current transformer interposing types can be used to modify the secondary current from an existing line ct. Ts are also used to correct the phase shift, which may result due to particular method of connection used for the. When used in providing transformer differential protection, these c. Current transformer calculations enter values in white, ct values are calculated automatically. Calculation and analysis of transformer inrush current.
Cp4 series encapsulated interposing current transformer. What is the function of interposing current transformer. Auto analyze windings connection to create desired vector group and define best choose for position of end leads of windings. Referring to the figure, the interposing current transformers icts have.
Ct winding arrangements, and software phase compensation are to be made. Bartype current transformer this type of current transformer uses the actual cable or busbar of the main circuit as the primary winding, which is equivalent to a single turn. Professionals with experience in transformer assemblies use the computer program to calculate the number of coils and wire thickness. Itl is a uk leading low voltage transformers manufacturer. Sample calculationfordifferentialrelays slideshare. The transformer calculator uses the following formulas. With modern numerical transformer differential relays all above compensations are provided in the relay software. Interposing cts also provide a convenient method of establishing a delta connection for the elimination of zero sequence currents where this is necessary. Calculation and analysis of transformer inrush current based on parameters of transformer and operating conditions article pdf available march 2011 with 16,021 reads how we. Pdf easy method for testing transformer differential relays. For engineering calculation purposes it is necessary to define only. This is useful for modifying secondary currents without replacing the line cts.
Please note that the interposing ct imposes an additional burden. The main purpose of a current transformer is to translate the primary current in a high voltage power system to a signal level that can be handled by delicate electromechanical or electronic devices. Chk gridsense, interposing ct,chk,gridsense chk power quality. It is important to note, however, that these solutions are best only for those experts who have knowledge and experience with assembly transformers. The standard current transformer secondary winding is rated at 5a as per ansi standards. Csh30 interposing ring current transformer ct installation sheet, instruction bulletin ansi, 63230216252a1, may 2007 published date. Interposing cts are equipment with a ratio that can be selected by the user to achieve the balance required.
Are you looking for the best transformer calculator software for your next project. Single phase transformer fullload current amps kva. The foremost interface device between the power system and the protective relaying is the ubiquitous current transformer. Current transformer calculation extreme electronics. For engineering calculation purposes it is necessary to define only one phasor in. Pdf differential protection for standard power transformers has. Ctdim is a software tool for current transformer ct and voltage potential. The main fuction of an interposing ct is to balance the current supplied to the relay or others where threre would otherwise be an imbalance due to the ratios of the main cts.