Fault Diagnosis of Transmission Lines with Rogowski Coils as Current Sensors

Abstract

This paper presents implementation of algorithms developed for fault classification and location detection on transmission lines with data from current & voltage sensors. Rogowski coil as current sensor is gaining importance due to its linearity and wide band width. A lumped parameter model of Rogowski coil is developed and integrated with a power system model in SIMULINK to simulate all types of faults at different locations, fault inception angles and fault resistances. A fault classification scheme based on the evaluation of angles of fault currents and voltages is extended to secondary values obtained from Rogowski coil. Further after estimation of phasors, fault location is detected. The test results show that the proposed algorithm on primary values is equally applicable on secondary values thus offering a fast and reliable technique for fault diagnosis of transmission lines in power systems.

Capacitive voltage sensors for an auxiliary fault locating service with travelling waves

“…As an alternative capacitive voltage dividers can be used for traveling wave measurement. Figure 5 shows the Rogowski coil electrical circuit according to [4] with the input voltage uin, the output voltage uout, the resistance R, the inductance L, the capacitance C and the termination impedance Z. The corresponding transfer function H1 is as in (7).…”

“…Figure 2, the fault distance calculation is based on local transient measurements only and exploits the reflection pattern of the fault generated traveling waves. Whereas in many other works a Rogowski coil is the preferred solution for traveling wave measurement as in [4], this work is based on the idea to exploit the capacitive voltage sensors within the medium voltage substation, as suggested in [5]. Those are capacitive voltage dividers as known from high voltage applications.…”

Use of Rogowski Coil as Current Transducer for Distance Relay Reach Correction

“…Where, i p is the current which is to be sensed and M is the mutual coupling between primary conductor and secondary winding [27]. The RC output voltage (V out ) in Laplace domain is given by Eq.6.…”