An autonomous sensor system for monitoring of high voltage overhead power supply lines

Abstract

Condition monitoring of overhead power lines is usually done by means of on-ground and helicopter-aided visual inspection. Therefore, the intervals between the inspections can be months or even years. In contrast, online condition monitoring provides a 24=7 observation of power lines and provides a better accuracy than remote monitoring. With energy harvesting from the electric field that surrounds the conductor, a monitoring system can operate as soon as the power line is turned on. Quantities of interest comprise the distance between conductor and ground (or other objects), temperature, degree of icing and vibrations and others. The measurement data can be transmitted to a relay station, e.g. using the 433 MHz ISM band, or utilizing the GSM or UMTS mobile phone networks. This paper presents a system concept, the energy harvesting and preliminary investigations on a capacitive icing sensor. Ein autonomes Sensorsystem zur € U Uberwachung von Hochspannungsfreileitungen. Zustands€ u uberwachung von Freileitungen erfolgt € u ublicherweise durch optische Inspektion vom Boden aus oder mit Hilfe von Hubschraubern. Diese € U Uberwachung erfolgt nur punktuell, und die Zeiten zwischen zwei Erfassungen sind typischerweise Monate oder Jahre. Im Gegensatz dazu bietet eine Echtzeit-Zustands€ u uberwachung eine durchgehende Erfassung. Rasche Ver€ a anderungen k€ o onnen damit schnell und zuverl€ a assig erkannt werden. Wird die Energie zur Versorgung der Sensoreinrichtung aus dem elektrischen Feld, das den Leiter umgibt, bezogen, steht ein System zur Verf€ u ugung, das unmittelbar mit Inbetriebnahme der Freileitung mit der € U Uberwachung beginnen kann. Interessierende Messgr€ o oßen umfassen dabei Temperatur des Leiterseils, Durchhang, Abstand zu Objekten bzw. zum Boden, Grad der Vereisung und Vibrationen. Die Messdaten k€ o onnen beispielsweise € u uber das 433-MHz-ISM-Band oder € u uber das GSM=UMTS-Netz an einen Zentralrechner € u ubermittelt werden. Der vorliegende Beitrag beschreibt ein Systemkonzept, Energieversorgung aus dem elektrischen Feld und erste Ergebnisse zur Ermittlung des Vereisungsgrads mit Hilfe eines kapazitiven Sensors. Schl€ u usselw€ o orter: Echtzeit-Prozess€ u uberwachung; Zuverl€ a assigkeit des Stromversorgungsnetzes; drahtlose Sensorik; kapazitive Sensoren; Eisdetektion

The development of a voltage transducer for faults monitoring on high voltage overhead lines using numerical methods

“…b w C C s π 2 l = (4) However, due to end-effects at the edges of the sensing probe, the extra capacitance within the gap between the sensing probe and the guard electrode needs to be taken into consideration, and is approximated by (5).…”

“…In order to obtain the equivalent capacitance between the sensing probe and HV conductor, the per unit length capacitance needs to be scaled to the dimensions (length, l and width, w of the sensing probe) of the sensing probe as shown in (4).…”

“…In addition, their frequency response is not adequate for the measurement of fast transient. Moreover, increases in power distribution system voltages which up to several hundred kV and load growth have led to increase operating stresses on the transformer insulation, which are becoming increasingly complex and costly [4].…”

The Design of CT Energy Harvesting Power Supply Based on Phase-Controlled Method

“…However, the method has the following difficulties: 1. The dead-region current is required to be reduced as much as possible [8], so enough power can be output at lower current in conductor; 2. When the current in conductor exceeds the rated current or it is even in the case of short circuit, energy harvesting devices can operate reliably [9]; 3.…”

Optimization Design of an Inductive Energy Harvesting Device for Wireless Power Supply System Overhead High-Voltage Power Lines

“…In recent years, domestic and foreign scholars have proposed several methods for HVPL fault diagnosis and online monitoring [3], but the problem of an convenient and efficient power supply for monitoring equipment remains unresolved. Previous studies [4][5][6][7] have introduced several commonly-used power supply methods: (1) on the basis of the capacitor dividing principle, energy obtained from electric fields around the power line can be used to power the monitoring equipment;…”