IEC 61869-15:2018 ED1

Instrument transformers - Part 15: Additional requirements for voltage transformers for DC applications

Scope

IEC 61869-15:2018 provides all requirements specific to voltage transformers to be used in DC applications (DCVTs), whatever the technology used. The output signal can be analogue or digital.
It is applicable to newly manufactured voltage transformers used for measuring, protection and/or control applications in DC power systems with a rated voltage above 1,5 kV.
This document covers passive voltage dividers as well as active voltage transformers, used for measurement, control and protection.
The general configuration of a single-pole low-power instrument transformer is described in Figure 601 of IEC 61869-6:2016.
IEC 61869-15:2018 applies to voltage transformers (VT) intended to be used in DC applications with the following functions:
• measure DC voltage (with significant harmonics);
• withstand DC voltage.
Two main technologies of DC converters exist today: LCC and VSC
• Line-commutated converters (LCC) are based on thyristor converters. They are characterized by a single direction of current flow, and a voltage polarity reversal possibility. Significant voltage and current harmonics exist up to frequencies of about 3 kHz to 4 kHz.
• Voltage source converters (VSC) are based on transistor converters. They are characterized by a bi-directional current flow and a single voltage polarity. Voltage and current harmonics exist up to frequencies of about 20 kHz.