Conceptual design and evaluation of an optical sensor for wide-area high-voltage metering and protection applications

Abstract

This paper considers the design of a fiber-optic voltage sensor for applications in the field of wide area monitoring, protection and control of high voltage power networks. The proposed 132-kV sensor, combining a capacitive voltage divider (CVD) and an optical medium voltage transducer (MVT), was theoretically evaluated through software simulations and its expected performance was assessed based on the operational requirements specified by the IEC standards for electronic voltage transformers. The simulation results suggest that the sensor, when fabricated, should be capable of meeting the requirements for metering and protection classes specified by the IEC 60044-7 standard.

Construction and Evaluation of an Optical Medium Voltage Transducer Module Aimed at a 132 kV Optical Voltage Sensor for WAMPAC Systems

“…Electricity distribution networks are essential to wide-area power systems and combine overhead lines, underground cables, and step-down transformers to distribute electrical power to primary and secondary customers [ 9 , 10 ]. Among many problems related to the electrical network functionality and stability are temporary or permanent faults potentially causing damage to electrical equipment and leading to temporary power outages or blackouts with durations sometimes reaching several hours [ 10 , 11 , 12 , 13 ]. Therefore, novel sensor systems offering remote and distributed voltage and current measurements while remaining cost-competitive with the current technology are desired for the developing WAMPAC systems.…”

“…Hard piezoelectric materials can be operated at higher voltages and demonstrate better linearity, smaller hysteresis, and better short- and long-term stability than the soft equivalents [ 10 ]. Narrower hysteresis in the hard PZTs directly translate into smaller phase displacements between input and output signals of the sensors.…”

“…It is also expected that long-term voltage-to-strain response of hard PZTs is superior over the soft PZTs due to the more stable material properties of the hard PZT transducers [ 19 , 20 , 21 ]. In the previous tests that were carried out by the authors, the effects of aging and de-aging (sensitivity changes) in the soft PZT were worse than those in the hard PZT [ 10 , 19 , 22 ], which is especially important at rapid signal changes, such as those during faults or lightning impulse events. However, for the application of the hard PZT for direct measurement of high voltage, a scaled-up version of the previous design for MV networks [ 16 , 18 ] does not seem to be feasible.…”

“…However, for the application of the hard PZT for direct measurement of high voltage, a scaled-up version of the previous design for MV networks [ 16 , 18 ] does not seem to be feasible. This is because the requirements for the limits of the permissible electric field in the PZT components and the consequent dimensions of the component do not seem to be practical for an HV sensor [ 10 ]. To protect the PZT stack against overvoltage conditions, it must be designed to withstand excessive voltage of power frequency and the lightning impulse tests, which requires large piezoelectric transducers.…”

“…This can be achieved by designing the sensor to operate at voltage levels being only a fraction of the sensor maximum working range, but the size of the component would not be practical in this case. Therefore, a medium-voltage hard piezoelectric transducer (MVT) was proposed by the authors as reported in [ 10 ] to work in tandem with a CVD. The proposed MVT is aimed at monitoring 132 kV networks, but it could easily be adapted to other network voltage levels by providing a suitable CVD.…”