UNE-EN IEC 61869-11:2019

This part 11 of IEC 61869 is a product standard and covers only additional requirements for low-power passive voltage transformers (passive LPVT). The product standard for low-power passive voltage transformers is composed by the IEC 61869-1, in addition with IEC 61869-6 and this standard with specific requirements.This International Standard is applicable to newly manufactured low-power passive voltage transformers with analogue output having rated frequencies from 15 Hz to 100 Hz for use with electrical measuring instruments or electrical protective devices.This Standard covers low-power passive voltage transformers used for measurement or protection and low-power passive voltage transformers used for both measurement and protection.Low-power passive voltage transformers are based on the voltage divider principle. They can be built for example as resistive dividers, capacitive dividers or resistive-capacitive dividers.Low-power passive voltage transformers have analogue output only (for digital output or for technology using any kind of active electronic components refer to IEC 61869-7). Such low-power passive voltage transformers may include the secondary signal cable (transmitting cable).According to a general block diagram given in Figure 601 (IEC 61869-6), the low-power passive voltage transformers do not use an active primary converter (i.e. without any active electronic component); therefore, there is no need for primary power supply. Additionally, neither the secondary converter nor the secondary power supply is used.The general block diagram of a low-power passive voltage transformer is given in Figure 1101.The applied technology decides which part is necessary for the realization of a low-power passive voltage transformer, i.e. it is not necessary that transmitting cable or primary converter described in Figure 1101 are included in the low-power passive voltage transformer.