Evaluation of Line Side Prospective Transient Recovery and Determination of Current Zero Crossing for Short Line Fault Interruption

The line side prospective transient recovery voltage (TRV) for circuit breakers should be measured by using a switching device with low stray elements and minimized or ideally no effects on the test circuit. A common method is the capacitor current injection circuit with a diode as a switching element described in IEC 62271‐100 annex E.3.3. This paper discusses the diode effects (current zero crossing, voltage drop, stray capacitance) on the determination of the line side TRV. Furthermore, the influence of stray elements from the current measuring sensors such as CTs and shunts on the current zero crossing was investigated. Other procedures to determine the prospective TRV for short line faults are the reverse current injection method and the current step response method. These methods will be introduced in this paper. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.