IEC 61869-10:2017 pdf download

IEC 61869-10:2017 pdf download.Instrument transformers – Part 10: Additional requirements for low-power passive current transformers
1 Scope
This part of IEC 61 869 is a product standard and covers only additional requirements for low- power passive current transformers. The product standard for low-power passive current transformers comprises IEC 61 869-1 , together with IEC 61 869-6 and this document with specific requirements. This document is applicable to newly manufactured low-power passive current transformers with analogue output for use with electrical measuring instruments or electrical protective devices having a rated frequency from 1 5 Hz to 1 00 Hz. This document covers low-power passive current transformers used for measurement or protection and multi-purpose low-power passive current transformers used for both measurement and protection. Subclause 5.6.1 001 covers the accuracy requirements that are necessary for low-power passive current transformers for use with electrical measuring instruments. Subclause 5.6.1 002 covers the accuracy requirements that are necessary for low-power passive current transformers for use with electrical protective relays, and particularly for forms of protection in which the prime requirement is to maintain the accuracy up to several times the rated current. If required, the transient accuracy of low-power passive current transformers during fault is also given in 5.6.1 002. Low-power passive current transformers have analogue voltage output only (for digital output or for technology using any kind of active electronic components refer to IEC 61 869-8 2 ). Such low-power passive current transformers can include the secondary signal cable (transmitting cable). The principle of operation of derivative low-power passive current transformers using air-core coils (Rogowski coils) is given in Annex 1 0B and the principle of operation of proportional low-power passive current transformers using iron-core coils with integrated shunt is given in Annex 1 0C.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. Clause 2 of IEC 61 869-6:201 6 is applicable with the following additions: IEC 60059, IEC standard current ratings IEC 61 869-6:201 6, Instrument transformers – Part 6: Additional general requirements for low- power instrument transformers
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61 869-1 and IEC 61 869-6 apply with the following additions and modifications. 3.1 General definitions 3.1 .61 3 transmitting system Definition 3.1 .61 3 of IEC 61 869-6:201 6 is applicable with the following addition: Note 1 001 to entry: For low-power passive current transformers the transmitting system is just a transmitting cable.
5.6.1 002 Accuracy based on individual corrected transformation ratio and corrected phase offset
As an alternative to the accuracy based on rated transformation ratio and rated phase offset, for passive LPCT the accuracy can be calculated based on the individual corrected transformation ratio or individual ratio correction factor and the individual corrected phase offset or individual phase offset correction factor. More information about the individual correction is shown in Annex 1 0A. Corrected ratio error ε cor I or corrected composite error ε c cor I is calculated by the formula in Note 1 of definitions 3.4.1 005 and 3.4.1 006. The correction factor CF I shall be in the range 0,900 to 1 ,1 00 and specified with the suitable accuracy and number of decimals according to the relevant accuracy class (with a minimal resolution of 0,001 ). The corrected phase error is calculated by the formula in Note 1 of definition 3.4.1 007. For passive LPCT the individual corrected phase offset φ cor φo replaces the rated phase offset φ or . Because rated delay time for passive LPCT is not applicable, φ tdr is zero. The phase offset correction shall be in the range of ±300 min and specified with the suitable accuracy and number of decimals according to the relevant accuracy class (with a minimal resolution of 1 min). If the accuracy is based on the individual correction, the correction factors or the corrected transformation ratio and the corrected phase offset shall be indicated on the rating plate. 5.6.1 003 Measuring low-power passive current transformers 5.6.1 003.1 Accuracy class designation for low-power passive current transformers For measuring passive LPCT, the accuracy class is designated by the highest permissible percentage of the ratio error (ε) at rated primary current and rated output.