High reliability and large working range induction energy harvesting device and control method based on adjustable impedance

Abstract

The present invention proposes a high-reliability and large-working-range induction energy-harvesting device based on adjustable impedance, including an energy-harvesting current transformer (energy-harvesting CT), an adjustable impedance circuit, an AC-DC conversion circuit, batteries and supercapacitor energy Management module and power load. By studying the influence of the secondary side load on the energy harvesting effect, the mathematical relationship between the active power output by the energy harvesting CT and the secondary side impedance is established. By adopting the method of paralleling the adjustable impedance on the secondary side, by adjusting the adjustable impedance, the required power output can be obtained when the primary side current changes in a large range. The present invention reduces the lower limit of the primary side current threshold of the energy-harvesting CT by means of parallel resonance, and raises the upper limit of the primary-side current threshold by means of adjustable impedance shunting, thereby broadening the working range of the energy-harvesting CT. And according to the mathematical relationship between the output power and the secondary side impedance, the energy harvesting CT can output the required target power when the primary side current fluctuates in a large range.

Description

technical field [0001] The invention relates to the technical field of power supply applied to an on-line monitoring system of a transmission line, in particular to an adjustable impedance-based high-reliability and large-working-range induction energy harvesting device and a control method. Background technique [0002] With the rapid development of smart grids, the voltage level and transmission capacity of power system transmission lines are constantly improving. On-line monitoring of the operating status of high-voltage transmission lines and accurate positioning of line faults have attracted more and more attention. In a high-voltage, strong electromagnetic environment, a stable and reliable power supply is the premise and basis for the long-term stable operation of the online monitoring device. [0003] In recent years, Chinese and foreign scholars have conducted a large number of fruitful researches on the power supply of transmission line on-line monitoring devices. ...

AI Technical Summary

Problems solved by technology

[0010] 2. When the current on the primary side is too large, that is: greater than the upper threshold, the magnetic circuit of the energy harvesting CT is saturated at this time, and cannot provide stable energy for the secondary side

But at the same time, it also brings many unfavorable factors such as large iron core volume, frequent battery charging and discharging, battery life limit, etc., which adversely affects the application range, cost and operation reliability of the entire energy harvesting device.

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