Actively Calibrated Capacitively Coupled Electrostatic Device for High Voltage Measurement

Stanford researchers have designed a capacitively coupled electrostatic device (CCED) for measuring high voltage. The CCED is compact, low cost, safe, easy to use, accurate, and actively calibrated. Current distribution line level Phasor Measurement Units (PMUs) or synchrophasors can be prohibitively expensive to install and can be unreliable due to line to ground paths. Alternatives are unable to reach the metering quality required due to changes in conductor and ground geometry. This invention addresses these shortcomings by integrating ungrounded, capacitively coupled devices with advanced signal processing and multiple sensors for calculating the device capacitance as well as line voltage phasor.
Stage of Research
Researchers have built and tested the line mounted device at low voltages. The next stage is to build and test a GPS enabled, distribution voltage level CCED with inexpensive wireless technology and self-powering electronics. If extensively deployed, this high voltage CCED will ease the integration of wind and solar power in the high-voltage grid, and increase the amount of energy that can be reliably transmitted.