A simulation analysis method and device for protection characteristics of power supply circuit of electric energy meter

Abstract

The invention discloses a method and a device for the simulation and analysis of the protection characteristic of the power circuit of an electric energy meter. The method comprises the following steps: obtaining the change of the resistance of a positive temperature coefficient thermistor in a pressure-sensitive and heat-sensitive composite resistor in the power circuit of an electric energy meter with temperature, and analyzing the dispersity of the Curie temperature at the positive temperature coefficient thermistor; measuring the electrical parameters of the transformer in the power circuit of the electric energy meter, substituting the obtained electrical parameters into a circuit simulation model and carrying out simulation to obtain the loss power of the transformer, and analyzing the dispersity of the loss power of the transformer; loading the loss power into a thermal simulation model, setting a limit condition as the thermal simulation condition, and carrying out thermal simulation to obtain the temperature distribution at the positive temperature coefficient thermistor under the limit condition; drawing a dispersity curve of the Curie temperature at the positive temperature coefficient thermistor and a curve of the influence of the loss power change of the transformer under the limit condition on the temperature of the thermistor; and analyzing the protection characteristic of the power circuit of the electric energy meter according to the two curves.

Description

technical field [0001] The present application relates to the technical field of electric energy meters, in particular to a method and device for simulating and analyzing protection characteristics of a power supply circuit of an electric energy meter. Background technique [0002] As a voltage conversion and energy supply module, the safe and reliable operation of the power circuit is particularly important for the normal operation of the meter. The power circuit is mainly composed of a transformer, a voltage stabilizing circuit and a voltage-sensitive thermistor composite resistor in front of the transformer. Under the premise of not achieving overvoltage and overcurrent protection, due to transformer heating and other reasons, the temperature at the PTC (Positive Temperature Coefficient, positive temperature coefficient) thermistor in the composite resistor may exceed its Curie temperature, thereby making its resistance The value increases exponentially, cut off the inpu...

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Problems solved by technology

[0004] The purpose of the embodiment of this application is to provide a simulation analysis method and device for the protection characteristics of the power supply circuit of the electric energy meter, and to solve the technical problem of low precision in the prior art for the research on the cooperation between the PTC thermistor and the transformer in the electric energy meter

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