An Electroscope System Based on Electric Field Measurement Method for UHV Transmission Lines

Abstract

The paper describes an electric field measurement method based electroscope system to check the electrification state of ultra-high voltage transmission lines, which is composed of three parts: 1) Measuring terminal; 2) Central sever; 3) GPRS and Internet network. The measuring terminal was used to measure the electric field and the location of the measuring points, then the measured data was sent to the central sever by GPRS and Internet network, and requested for an electricity state confirmation.When the sever received a request from a terminal, the electric fields and locations of the measuring points were obtained first, then according to the location of the measuring points, the server searches the corresponding objective transmission lines in the database and read their parameters. According to the parameters of the measuring points and transmission lines, a calculation would be carried out to confirm the electrification state of the transmission lines. For the confirmation calculation, equations for the electric field inverse problem of the transmission lines were set up first, then global regularization and damped Gauss Newton (DGN) method were used to solve the inverse problem.A 500kV double loops transmission line was taken as an example to verify the validity of this method. The electric field and location of 11 measuring points were measured by the measuring terminal firstly, and then sent to the central sever. Electrification state was confirmed by the central sever.

Research on Power Distribution Control of Parallel Inverters in Off-grid Mode

“…(1) The value of active power and reactive power output by the inverter is shown in Equation (2) and equation (3).…”

“…With the rapid progress of new energy power generation technology, wind power and photovoltaics become the main force of new power supply [1] . To accelerate the consumption of new energy, it is inevitable that there are multiple new energy units at the same time and space, which will involve the control problem of parallel operation of multiple inverters [2][3] .…”