On-line evaluation method of switching resistor of transformer substation in three-second wiring mode

Abstract

The invention discloses an on-line evaluation method of a switching resistor of a transformer substation in a three-second wiring mode. The method is realized based on a CRIO platform. A current collection card arranged on the CRIO platform is used for obtaining switching currents at different moments; an inequality constraint condition of the switching resistor and the current is established based on a Kirchhoff voltage law and a maximum value of the switching resistor of the transformer substation is selected as a target function, thereby establishing an optimum planning model of the switching resistor; and then an optimum planning model is resolved by using a genetic algorithm. According to the invention, an effect of on-line operation resistor evolution of the switch in the three-second transformer substation can be realized effectively; a fault switch in the transformer substation can be found timely; and the result has the obvious parameter identification effect.

Description

technical field [0001] The invention belongs to the technical field of power system analysis, in particular to an online evaluation method for switch resistance of a 3 / 2 connection mode substation. Background technique [0002] In engineering applications, the most commonly used methods for measuring switch resistance in substations are the DC voltage drop method and the DC double-arm bridge method. The DC voltage drop method is to pass a constant large current of more than 100A to the switch, measure the voltage drop at both ends of the switch, and calculate the contact resistance value of the switch according to Ohm's law. However, the disadvantage of this method is that passing a constant large current for a long time will easily cause excessive heat and accelerated oxidation of the contacts, which will cause additional errors in the measured value of the contact resistance, and the usually used large current generators are relatively large in size and weight, which is no...

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Problems solved by technology

This method needs to select working conditions from a large amount of current data, and the calculation amount is relatively large, and errors such as instantaneous current phase are ignored in the process of establishing the equation, and the calculation results are not accurate enough.

[0004] It can be seen from the above that there is no method in the prior art to accurately evaluate the resistance value of the switchgear in the 3 / 2 wiring mode substation

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