A New Line Temperature Transmitting Device

Abstract

The present invention discloses a novel line temperature transmission device used for leading the current of the secondary winding of a CT (current transformer) to a heating resistor loop in line temperature measurement of the power transformer. The device includes a current acquisition module for acquiring the current of the secondary winding of the CT, a control circuit and an alternating-current constant current source circuit for leading output current to the heating resistor loop; the control circuit comprises a central processing unit and a liquid crystal display module; the alternating-current constant current source circuit is connected with the central processing unit through a serial communication circuit; the current acquisition module is connected with the central processing unit; and the liquid crystal display module is connected with the central processing unit. According to the novel line temperature transmission device of the invention, a current acquisition sensor is adopted to acquire the current of the secondary winding; the central processing unit processes acquired current data and communicates with the alternating-current constant current source circuit so as to control the magnitude of output current, so that the output current of the alternating-current constant current source circuit and acquired input current can be synchronous and consistent, and therefore, the risk of the open circuiting of the secondary winding of the CT can be lowered, and the stability of a transformer system can be improved.

Description

technical field

[0001] The invention relates to a line temperature transmission device, in particular to a line temperature transmission device for measuring the temperature of a secondary winding current during line temperature measurement of a power transformer. Background technique

[0002] At present, the method of measuring the line temperature of the power transformer is mainly that the current of the secondary winding of the CT flows through the heating resistor to compensate the oil temperature, and the line temperature of the transformer is obtained after conversion. Since this measurement method connects resistors in series in the CT secondary winding circuit, and the environment around the converter transformer is relatively harsh, there is a risk of resistor burnout in long-term operation, causing the CT secondary winding to open and threatening the safety of the transformer. run. At present, the temperature measurement principle of the winding at home and abroa...

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